JP3697199B2 - Solar cell manufacturing method and solar cell - Google Patents

Description

【００７０】
前記表１から明らかなようにＳｉＨ₂Ｃｌ₂を全Ｓｉガスの流量に対して流量比で１０〜４０％の範囲で添加した原料ガスを用いて製膜した実施例１のｉ型微結晶Ｓｉ層は、ＳｉＨ₂Ｃｌ₂を添加せずＳｉＨ₄およびＨ₂からなる原料ガスを用いて製膜した比較例１のｉ型微結晶Ｓｉ層に比べて（１１０）配向比が5倍以上の２９の値を示すことがわかる。
【００７１】
また、実施例１および比較例１の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、試料温度：室温）をそれらの透明絶縁性基板側から入射し、発電特性を評価した。その結果を図４に示す。
【００７２】
図４から明らかなように実施例１の太陽電池は、比較例１の太陽電池に比べて短絡電流が向上されることがわかる。これは、実施例１の太陽電池を構成するｉ型微結晶Ｓｉ層の（１１０）配向比が向上されたためである。
【００７３】
（実施例２）
この実施例２では、透明絶縁性基板側から光を入射するタイプでｐｉｎ構造が多結晶Ｓｉからなる太陽電池の製造工程を図５を参照して説明する。
【００７４】
まず、光透過を有する青板ガラスからなる透明絶縁性基板１１上に酸化錫からなる第１透明電極１２を形成した。
【００７５】
次いで、前述した図１に示すプラズマＣＶＤ装置におけるｐ層製膜用反応容器１内の陽極３に前記透明電極１２が形成された透明絶縁性基板１１を被処理物８として保持し、被処理物８をリードを通して接地された反応容器１に接続した後、図示しない真空ポンプを作動して排気管７を通して前記反応容器１内を１×１０^-8Ｔｏｒｒ以下に真空排気した。つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１８０℃の温度に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＢ₂Ｈ₆をガス供給管６を通して導入し、反応容器１内を５００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から周波数１００ＭＨｚの高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８の第１透明電極１２上に厚さ３００ｎｍのｐ型多結晶Ｓｉ層１８を製膜した。
【００７６】
次いで、ｐ型多結晶Ｓｉ層１８を製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｉ層製膜用の反応容器１内に被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を２１０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器内１に原料ガスであるＳｉＨ₄とＳｉＨ₂Ｃｌ₂とＨ₂との混合ガスをガス供給管６を通して導入した後、反応容器１内の圧力を１.０Ｔｏｒｒに制御した。このとき、前記各ガスの量はＳｉＨ₄：５〜１０ｓｃｃｍ、ＳｉＨ₂Ｃｌ₂（１％水素希釈）：１００〜２００ｓｃｃｍ、Ｈ₂：１００〜２００ｓｃｃｍとした。また、ＳｉＨ₂Ｃｌ₂は全Ｓｉガスの流量に対して流量比で１０〜３０％の範囲であった。原料ガスを導入した後、反応容器１内の温度及び圧力を十分安定させた後、高周波電源４からインピーダンス整合器５を通して放電用はしご型電極２に周波数１００ＭＨｚ、１００ｍＷ／ｃｍ²の高周波電力を供給することによりプラズマを発生させ、前記ｐ型多結晶Ｓｉ層１８上に厚さ１５００ｎｍのｉ型多結晶Ｓｉ層１９を製膜した。このｉ型多結晶Ｓｉ層１８は、塩素を４×１０¹⁹ｃｍ^-3含有されていた。
【００７７】
次いで、ｉ型多結晶Ｓｉ層１９の製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｎ層製膜用の反応容器１内へ被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１８０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、この反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＰＨ₃をガス供給管６を通して導入し、反応容器１内を７００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８のｉ型多結晶Ｓｉ層１９上に厚さ３０ｎｍのｎ型多結晶Ｓｉ層２０を製膜した。この後、前記被処理物をプラズマＣＶＤ層の反応容器１から取り出し、前記ｎ型多結晶Ｓｉ層２０に酸化インジウムからなる第２透明電極１６およびＡｌからなる裏面電極１７を順次形成して図５に示す太陽電池を製造した。
【００７８】
実施例２で製膜したｉ型多結晶Ｓｉ層の（１１０）配向比を調べた結果、実施例１と同様な２９の値を示した。
【００７９】
また、実施例２の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその透明絶縁性基板側から入射し、発電特性を評価した。その結果は、実施例１と同様な大きな短絡電流が得られた。
【００８０】
（実施例３）
この実施例３では、透明絶縁性基板側から光を入射するタイプでｐｉｎ構造が微結晶Ｓｉからなり、かつタンデム構造を有する太陽電池の製造工程を図６を参照して説明する。
【００８１】
まず、光透過を有する青板ガラスからなる透明絶縁性基板１１上に酸化錫からなる第１透明電極１２を形成した。
【００８２】
次いで、前述した図１に示すプラズマＣＶＤ装置における反応容器１内の陽極３に前記透明電極１２が形成された透明絶縁性基板１１を被処理物８として保持し、被処理物８をリードを通して接地された反応容器１に接続した後、図示しない真空ポンプを作動して排気管７を通して前記反応容器１内を１×１０^-8Ｔｏｒｒ以下に真空排気した。つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１３０℃の温度に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＢ₂Ｈ₆をガス供給管６を通して導入し、反応容器１内を１００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から周波数１３.５６ＭＨｚの高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８の第１透明電極１２上に厚さ３０ｎｍのｐ型アモルファスＳｉ層３１を製膜した。
【００８３】
次いで、ｐ型アモルファスＳｉ層３１を製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｉ層製膜用の反応容器１内に被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１６０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄（流量：５０ｓｃｃｍ）およびＨ₂（流量：５０ｓｃｃｍ）をガス供給管６を通して導入した後、反応容器１内の圧力を１００ｍＴｏｒｒに制御した。原料ガスを導入した後、反応容器１内の温度及び圧力を十分安定させた後、高周波電源４からインピーダンス整合器５を通して放電用はしご型電極２に周波数６０ＭＨｚ、２００ｍＷ／ｃｍ²の高周波電力を供給することによりプラズマを発生させ、前記ｐ型アモルファスＳｉ層３１上に厚さ３００ｎｍのｉ型アモルファスＳｉ層３２の製膜した。
【００８４】
次いで、ｉ型アモルファスＳｉ層３２の製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｎ層製膜用の反応容器１内へ被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１３０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、この反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＰＨ₃をガス供給管６を通して導入し、反応容器１内を１００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８のｉ型アモルファスＳｉ層３２上に厚さ４０ｎｍのｎ型アモルファスＳｉ層３３を製膜した。
【００８５】
次いで、ｎ型アモルファスＳｉ層３３上に前述した実施例１と同様な方法によりｐ型微結晶Ｓｉ層１３、ｉ型微結晶Ｓｉ層１４、ｎ型微結晶Ｓｉ層１５、酸化インジウムからなる第２透明電極１６およびＡｌからなる裏面電極１７を順次形成して図６に示すタンデム構造の太陽電池を製造した。
【００８６】
実施例３の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその透明絶縁性基板側から入射し、発電特性を評価した。その結果、比較例１を上記タンデムに適用した場合に比べて大きな短絡電流値１.１０（相対値）が得られた。
【００８７】
（実施例４）
この実施例４では、透明絶縁性基板側から光を入射するタイプでｐｉｎ構造が多結晶Ｓｉからなり、かつタンデム構造を有する太陽電池の製造工程を図７を参照して説明する。
【００８８】
まず、光透過を有する青板ガラスからなる透明絶縁性基板１１上に酸化錫からなる第１透明電極１２を形成した。つづいて、この透明電極１２上に実施例３と同様な方法によりｐ型アモルファスＳｉ層３１、ｉ型アモルファスＳｉ層３２およびｎ型アモルファスＳｉ層３３を順次製膜した。ひきつづき、ｎ型アモルファスＳｉ層３３上に前述した実施例２と同様な方法によりｐ型多結晶Ｓｉ層１８、ｉ型多結晶Ｓｉ層１９、ｎ型多結晶Ｓｉ層２０、酸化インジウムからなる第２透明電極１６およびＡｌからなる裏面電極１７を順次形成して図７に示すタンデム構造の太陽電池を製造した。
【００８９】
実施例４の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその透明絶縁性基板側から入射し、発電特性を評価した。その結果、実施例３と同様に大きな短絡電流値が得られた。
【００９０】
（実施例５）
この実施例５では、第２透明電極側から光を入射するタイプでｎｉｐ構造が微結晶Ｓｉからなる太陽電池の製造工程を図８を参照して説明する。
【００９１】
まず、光透過を有する青板ガラスからなる透明絶縁性基板４１上にＡｌからなる裏面電極４２および酸化亜鉛（ＺｎＯ）からなる第１透明電極４３を形成した。
【００９２】
次いで、前述した図１に示すプラズマＣＶＤ装置におけるｎ層製膜用の反応容器１内の陽極３に前記透明電極４３が形成された透明絶縁性基板４１を被処理物８として保持し、被処理物８をリードを通して接地された反応容器１に接続した後、図示しない真空ポンプを作動して排気管７を通して前記反応容器１内を１×１０^-8Ｔｏｒｒ以下に真空排気した。つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１６０℃の温度に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＰＨ₃をガス供給管６を通して導入し、反応容器１内を７００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から周波数１００ＭＨｚの高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８の第１透明電極４３上に厚さ３０ｎｍのｎ型微結晶Ｓｉ層４４を製膜した。
【００９３】
次いで、ｎ型微結晶Ｓｉ層４４を製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｉ層製膜用の反応容器１内に被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１９０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器内１に反応容器１内に原料ガスであるＳｉＨ₄とＳｉＨ₂Ｃｌ₂とＨ₂との混合ガスをガス供給管６を通して導入した後、反応容器１内の圧力を２.０Ｔｏｒｒに制御した。このとき、前記各ガスの量はＳｉＨ₄：３〜７ｓｃｃｍ、ＳｉＨ₂Ｃｌ₂（１％水素希釈）：５０〜２５０ｓｃｃｍ、Ｈ₂：１００〜２５０ｓｃｃｍとした。また、ＳｉＨ₂Ｃｌ₂は全Ｓｉガスの流量に対して流量比で１０〜４０％の範囲であった。原料ガスを導入した後、反応容器１内の温度及び圧力を十分安定させた後、高周波電源４からインピーダンス整合器５を通して放電用はしご型電極２に周波数１００ＭＨｚ、１０Ｗの高周波電力を供給することによりプラズマを発生させ、前記ｎ型微結晶Ｓｉ層４４上に厚さ１５００ｎｍのｉ型微結晶Ｓｉ層４５の製膜した。このｉ型微結晶Ｓｉ層４５は、塩素を６×１０¹⁹ｃｍ^-3含有されていた。
【００９４】
次いで、ｉ型微結晶Ｓｉ層４５の製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｐ層製膜用の反応容器１内へ被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１６０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、この反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＢ₂Ｈ₆をガス供給管６を通して導入し、反応容器１内を５００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８のｉ型微結晶Ｓｉ層４５上に厚さ３０ｎｍのｐ型微結晶Ｓｉ層４６を製膜した。この後、前記被処理物をプラズマＣＶＤ層の反応容器１から取り出し、前記ｐ型微結晶Ｓｉ層４６に酸化インジウムからなる第２透明電極４７を形成して図８に示す太陽電池を製造した。
【００９５】
実施例５で製膜したｉ型微結晶Ｓｉ層の（１１０）配向比を調べた結果、実施例１と同様な２９の値を示した。
【００９６】
また、実施例５の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその第２透明電極側から入射し、発電特性を評価した。その結果は、実施例１と同様な大きな短絡電流が得られた。
【００９７】
（実施例６）
この実施例６では、第２透明電極側から光を入射するタイプでｎｉｐ構造が多結晶Ｓｉからなる太陽電池の製造工程を図９を参照して説明する。
【００９８】
まず、光透過を有する青板ガラスからなる透明絶縁性基板４１上にＡｌからなる裏面電極４２および酸化亜鉛（ＺｎＯ）からなる第１透明電極４３を形成した。
【００９９】
次いで、前述した図１に示すプラズマＣＶＤ装置におけるｎ層製膜用の反応容器１内の陽極３に前記透明電極４３が形成された透明絶縁性基板４１を被処理物８として保持し、被処理物８をリードを通して接地された反応容器１に接続した後、図示しない真空ポンプを作動して排気管７を通して前記反応容器１内を１×１０^-7Ｔｏｒｒ以下に真空排気した。つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１８０℃の温度に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＰＨ₃をガス供給管６を通して導入し、反応容器１内を７００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から周波数１００ＭＨｚの高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８の第１透明電極４３上に厚さ３００ｎｍのｎ型多結晶Ｓｉ層４８を製膜した。
【０１００】
次いで、ｎ型多結晶Ｓｉ層４８を製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｉ層製膜用の反応容器１内へ被処理物８を移動し上記ｎ型微結晶Ｓｉ層１３の製膜と同様にセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を２１０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、反応容器１内に原料ガスであるＳｉＨ₄とＳｉＨ₂Ｃｌ₂とＨ₂との混合ガスをガス供給管６を通して導入した後、反応容器１内の圧力を１.０Ｔｏｒｒに制御した。このとき、前記各ガスの量はＳｉＨ₄：５〜１０ｓｃｃｍ、ＳｉＨ₂Ｃｌ₂（１％水素希釈）：１００〜２００ｓｃｃｍ、Ｈ₂：１００〜２００ｓｃｃｍとした。また、ＳｉＨ₂Ｃｌ₂は全Ｓｉガスの流量に対して流量比で１０〜３０％の範囲であった。原料ガスを導入した後、反応容器１内の温度及び圧力を十分安定させた後、高周波電源４からインピーダンス整合器５を通して放電用はしご型電極２に周波数１００ＭＨｚ、７０ｍＷ/ｃｍ²の高周波電力を供給することによりプラズマを発生させ、前記ｎ型多結晶Ｓｉ層４８上に厚さ１５００ｎｍのｉ型多結晶Ｓｉ層４９の製膜した。このｉ型多結晶Ｓｉ層４９は、塩素を４×１０¹⁹ｃｍ^-3含有されていた。
【０１０１】
次いで、ｉ型多結晶Ｓｉ層４９の製膜後、原料ガスの供給を停止し、反応容器１内を真空排気した。つづいて、ｐ層製膜用の反応容器１内へ被処理物８を移動し上記製膜と同様の手順でセットした。１×１０^-7Ｔｏｒｒ以下に真空排気した後、つづいて、陽極３に内蔵された加熱ヒーターに通電し、前記被処理物８の基板を１８０℃に加熱した。加熱ヒーターによる加熱温度が十分安定した後、この反応容器１内に原料ガスであるＳｉＨ₄、Ｈ₂およびＢ₂Ｈ₆をガス供給管６を通して導入し、反応容器１内を７００ｍＴｏｒｒの圧力に制御した。反応容器１内の温度および圧力が十分安定した後、高周波電源４から高周波電力をインピーダンス整合器５を通して放電用はしご型電極２に供給することにより前記放電用はしご型電極２と前記被処理物８の間にプラズマ９を発生させ、前記被処理物８のｉ型多結晶Ｓｉ層４９上に厚さ３０ｎｍのｐ型多結晶Ｓｉ層５０を製膜した。この後、前記被処理物をプラズマＣＶＤ層の反応容器１から取り出し、前記ｐ型多結晶Ｓｉ層５０に酸化インジウムからなる第２透明電極４７を形成して図９に示す太陽電池を製造した。
【０１０２】
実施例６で製膜したｉ型多結晶Ｓｉ層の（１１０）配向比を調べた結果、実施例１と同様な２９の値を示した。
【０１０３】
また、実施例６の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその第２透明電極側から入射し、発電特性を評価した。その結果は、実施例１と同様な大きな短絡電流が得られた。
【０１０４】
（実施例７）
この実施例７では、第２透明電極側から光を入射するタイプでｎｉｐ構造が微結晶Ｓｉからなり、かつタンデム構造を有する太陽電池の製造工程を図１０を参照して説明する。
【０１０５】
まず、光透過を有する青板ガラスからなる透明絶縁性基板４１上にＡｌからなる裏面電極４２および酸化錫からなる第１透明電極４３を形成した。つづいて、この第２透明電極４３上に実施例５と同様な方法によりｎ型微結晶Ｓｉ層４３、ｉ型微結晶Ｓｉ層４４、ｐ型微結晶Ｓｉ層４５を順次形成した。ひきつづき、ｐ型微結晶Ｓｉ層４５上に実施例３と同様な方法によりｎ型アモルファスＳｉ層５１、ｉ型アモルファスＳｉ層５２およびｐ型アモルファスＳｉ層５３を順次製膜し、さらに酸化インジウムからなる第２透明電極４７を形成して図１０に示すタンデム構造の太陽電池を製造した。
【０１０６】
実施例７の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその第２透明電極側から入射し、発電特性を評価した。その結果、比較例１を上記タンデムに適用した場合に比べて大きな短絡電流値１.１０（相対値）が得られた。
【０１０７】
（実施例８）
この実施例８では、透明絶縁性基板側から光を入射するタイプでｎｉｐ構造が多結晶Ｓｉからなり、かつタンデム構造を有する太陽電池の製造工程を図１１を参照して説明する。
【０１０８】
まず、光透過を有する青板ガラスからなる透明絶縁性基板４１上にＡｌからなる裏面電極４２および酸化錫からなる第１透明電極４３を形成した。つづいて、この第２透明電極４３上に実施例６と同様な方法によりｎ型多結晶Ｓｉ層４８、ｉ型多結晶Ｓｉ層４９、ｐ型多結晶Ｓｉ層５０を順次形成した。ひきつづき、ｐ型多結晶Ｓｉ層５０上に実施例３と同様な方法によりｎ型アモルファスＳｉ層５１、ｉ型アモルファスＳｉ層５２およびｐ型アモルファスＳｉ層５３を順次製膜し、さらに酸化インジウムからなる第２透明電極４７を形成して図１１に示すタンデム構造の太陽電池を製造した。
【０１０９】
実施例８の太陽電池に模擬太陽光（スペクトル：ＡＭ１．５、照射強度：１００ｍＷ／ｃｍ²、照射温度：室温）をその第２透明電極側から入射し、発電特性を評価した。その結果、実施例７と同様に大きな短絡電流値が得られた。
【０１１０】
【発明の効果】
以上詳述したように本発明によれば、透明絶縁性基板上に第１透明電極、ｐｉｎ構造またはｎｉｐ構造を持つ微結晶シリコン層または多結晶シリコン層、第２透明電極および裏面電極を順次形成し、前記透明絶縁性基板側から光を入射させる構造の太陽電池の製造において、少なくともｉ型の微結晶シリコン層または多結晶シリコン層を従来技術に比べてより低温で、かつ低コストで製膜することによって前記第１透明電極の光透過性の低下、ｐｉ接合界面またはｎｉ接合界面での電気特性の劣化を招くことなく、前記ｉ型の微結晶シリコン層または多結晶シリコン層を（１１０）優先配向させることを可能にし、ひいては短絡電流のような発電特性が向上された太陽電池の製造方法を提供することができる。
【０１１１】
また、本発明によれば透明絶縁性基板上に裏面電極、第１透明電極、ｐｉｎ構造またはｎｉｐ構造を持つ微結晶シリコン層または多結晶シリコン層および第２透明電極を順次形成し、前記第２透明電極側から光を入射させる構造の太陽電池の製造において、少なくともｉ型の微結晶シリコン層または多結晶シリコン層を従来技術に比べてより低温で、かつ低コストで製膜することによって前記第１透明電極の光透過性の低下、ｐｉ接合界面またはｎｉ接合界面での電気特性の劣化を招くことなく、前記ｉ型の微結晶シリコン層または多結晶シリコン層を（１１０）優先配向させることを可能にし、ひいては短絡電流のような発電特性が向上された太陽電池の製造方法を提供することができる。
【０１１２】
さらに、本発明によれば（１１０）優先配向性を示すｉ型の微結晶シリコン層または多結晶シリコン層を含むｐｉｎ構造の微結晶シリコン層または多結晶シリコン層を有し、短絡電流のような発電特性が向上された太陽電池を提供することができる。
【図面の簡単な説明】
【図１】本発明の太陽電池を製造したプラズマＣＶＤ装置の断面図。
【図２】放電用はしご型電極の平面図。
【図３】本発明の実施例１におけるの太陽電池の構造を示す断面図。
【図４】本発明の実施例１および比較例１における太陽電池の短絡電流を示す特性図。
【図５】本発明の実施例２におけるの太陽電池の構造を示す断面図。
【図６】本発明の実施例３におけるの太陽電池の構造を示す断面図。
【図７】本発明の実施例４におけるの太陽電池の構造を示す断面図。
【図８】本発明の実施例５におけるの太陽電池の構造を示す断面図。
【図９】本発明の実施例６におけるの太陽電池の構造を示す断面図。
【図１０】本発明の実施例７におけるの太陽電池の構造を示す断面図。
【図１１】本発明の実施例８におけるの太陽電池の構造を示す断面図。
【図１２】従来の太陽電池の構造を示す断面図。
【図１３】従来の太陽電池の製造工程での問題点を説明するための断面図。
【図１４】従来の太陽電池の製造工程での他の問題点を説明するための断面図。
【符号の説明】
１…反応容器、
２…放電用はしご型電極、
３…陽極、
４…高周波電源、
５…整合器、
６…ガス供給管、
７…排気管、
８…被処理物、
９…プラズマ、
１１，４１…透明絶縁性基板、
１２，４２…第１透明電極、
１３，４６…ｐ型微結晶Ｓｉ層、
１４，４５…ｉ型微結晶Ｓｉ層、
１５，４４…ｎ型微結晶Ｓｉ層、
１６，４７…第２透明電極、
１７，４２…裏面電極、
１８，５０…ｐ型多結晶Ｓｉ層、
１９，４９…ｉ型多結晶Ｓｉ層、
２０，４８…ｎ型多微結晶Ｓｉ層、
３１，５３…ｐ型アモルファスＳｉ層、
３２，５２…ｉ型アモルファスＳｉ層、
３３，５１…ｎ型アモルファスＳｉ層。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a solar cell and a solar cell, and more particularly, to a solar cell having an improved i-type microcrystalline silicon layer or polycrystalline silicon layer among microcrystalline silicon layers or polycrystalline silicon layers having a pin structure. The present invention relates to a method and a solar cell.
[0002]
[Prior art]
In a solar cell having a thin-film crystalline silicon layer (microcrystalline Si layer or polycrystalline Si layer) having a pin structure, the quality of the i-type microcrystalline Si layer or polycrystalline Si layer as a power generation layer is improved (mainly (110 It is known that it is useful to improve the photoelectric conversion efficiency. The (110) preferred orientation is generally determined by comparing the diffraction intensity from the (220) plane with the diffraction intensity from other planes in the X-ray diffraction pattern. Here, in the thin film silicon crystal formed by plasma CVD, The ratio of the diffraction intensity between the (220) plane and the (111) plane, which is the main peak, is defined as the (110) orientation ratio.
[0003]
By the way, in the Vol. 63 No. 1 and No. 2 of the Institute of Electronics Technology Research Institute, i-type microcrystalline Si layer (i layer) is made SiH._FourA gas is introduced into a chamber of a plasma CVD apparatus as a raw material gas to generate plasma in the chamber and to form a film at an atmospheric temperature (temperature of the substrate to be processed) higher than 350 ° C. , It is disclosed that the i layer exhibits (110) preferential orientation. However, for example, in the production of a solar cell having a pin structure of thin-film crystalline silicon (microcrystalline Si or polycrystalline Si) by making light incident from the surface of a transparent insulating substrate, the i layer is produced at a high temperature exceeding 300 ° C. The film causes the following problems.
[0004]
That is, as shown in FIG. 12, the solar cell having the simplest structure has a first transparent electrode 102, a p-type microcrystalline Si layer (p layer) 103, an i-type microcrystalline Si layer (i Layer) 104, n-type microcrystalline Si layer (n layer) 105, second transparent electrode 106, and back electrode 107 are sequentially formed. The first and second transparent electrodes 102 and 106 are usually made of metal oxide such as tin oxide, but H is a source gas when the i layer 104 is formed.₂Or SiH_FourHydrogen radicals derived from gas are generated in the plasma. As shown in FIG. 13, when the hydrogen radical diffuses in the p layer 103 and reaches the lower first transparent electrode 102, oxygen of the metal oxide as the electrode material is extracted by a reduction reaction. Since the reduction reaction is remarkably accelerated when the i layer 104 is formed at a high temperature, the transparency of the first transparent electrode 102 decreases, the light transmittance decreases, and the photoelectric conversion efficiency decreases. .
[0005]
Further, by heating the transparent insulating substrate 101 to a high temperature, diffusion of p-type impurities (for example, boron) from the p layer 103 to the i layer 104 is promoted as shown in FIG. Since the p-type diffusion layer 108 is formed on the 104 side, the electrical characteristics of the junction interface deteriorates, the leakage current increases, and the photoelectric conversion efficiency decreases.
[0006]
Therefore, when the substrate temperature is increased to form the i-type microcrystalline Si layer 104 having the (110) preferential orientation as in the prior art, the optical characteristics of the transparent electrode 102 are deteriorated and the p-type at the pi junction interface is formed. Deterioration of electrical characteristics due to the generation of the diffusion layer 108 occurs, resulting in a problem of reducing the photoelectric conversion efficiency.
[0007]
Further, on the transparent insulating substrate, a back electrode, a first transparent electrode, an n-type microcrystalline Si layer (n layer), an i-type microcrystalline Si layer (i layer), a p-type microcrystalline Si layer (p layer), and Even in a solar cell having a structure in which the second transparent electrode is sequentially formed and light is incident from the second transparent electrode side, when the i layer is formed at a high temperature exceeding 300 ° C. as described above, the first transparent electrode This results in a decrease in light transmittance and a decrease in photoelectric conversion efficiency due to the formation of an n-type impurity layer on the i-layer side of the ni junction interface.
[0008]
[Problems to be solved by the invention]
In the present invention, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed on a transparent insulating substrate, and the transparent insulating substrate side In the manufacture of a solar cell having a structure in which light is incident from the first transparent electrode, at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer is formed at a lower temperature and at a lower cost than in the prior art. The i-type microcrystalline silicon layer or polycrystalline silicon layer can be (110) preferentially oriented without incurring a decrease in light transmittance and deterioration of electrical characteristics at the pi junction interface or ni junction interface. An object of the present invention is to provide a method for manufacturing a solar cell.
[0009]
In the present invention, a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, and the second transparent electrode side is formed. In the manufacture of a solar cell having a structure in which light is incident from the first transparent electrode, at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer is formed at a lower temperature and at a lower cost than in the prior art. The i-type microcrystalline silicon layer or polycrystalline silicon layer can be (110) preferentially oriented without incurring a decrease in light transmittance and deterioration of electrical characteristics at the pi junction interface or ni junction interface. An object of the present invention is to provide a method for manufacturing a solar cell.
[0010]
The present invention intends to provide a solar cell having a pin structure microcrystalline silicon layer or polycrystalline silicon layer including an i-type microcrystalline silicon layer or polycrystalline silicon layer exhibiting (110) preferential orientation. .
[0011]
[Means for Solving the Problems]
  A method for manufacturing a solar cell according to the present invention includes a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode on a transparent insulating substrate. In order to produce a solar cell in which light is incident from the transparent insulating substrate side,
  A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging the gas in the reaction vessel, a discharge ladder electrode disposed in the reaction vessel, and A power supply for supplying glow discharge generating power to the discharge ladder electrode, and a support electrode that is disposed in parallel with the discharge ladder electrode in the reaction vessel in parallel with the heater for heating. Using a CVD device,
  Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer has a transparent insulating substrate as a support electrode of the CVD apparatus. SiH is heated by supporting the processed material._FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂As a raw material gasThe chlorinated silicon-based compound gas is the SiH _Four And 1 to 80% of the total flow rate of the chlorinated silicon compound gasBy supplying the gas supply means into the reaction vessel, and supplying the ladder-type electrode with high frequency power for generating glow discharge having a frequency of 60 MHz or more from the power source to cause glow discharge in the reaction vessel to generate plasma. Film-formedAnd 1 × 10 chlorine ¹⁸ cm ^-3 ~ 8x10 ²⁰ cm ^-3 ContainIt is characterized by that.
[0012]
  A method for manufacturing a solar cell according to the present invention includes a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode on a transparent insulating substrate. In order to manufacture a solar cell in which light is incident from the second transparent electrode side,
  A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging the gas in the reaction vessel, a discharge ladder electrode disposed in the reaction vessel, and A power supply for supplying glow discharge generating high-frequency power to the discharge ladder-type electrode, and a support electrode that is disposed in parallel with the discharge ladder-type electrode in the reaction container and is parallel to the discharge ladder-type electrode. Use a CVD device with
  Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer has a transparent insulating substrate as a support electrode of the CVD apparatus. SiH is heated by supporting the processed material._FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂As a raw material gasThe chlorinated silicon-based compound gas is the SiH _Four And 1 to 80% of the total flow rate of the chlorinated silicon compound gasProduced by supplying plasma from the gas supply means into the reaction vessel, supplying glow discharge generation power having a frequency of 60 MHz or more from the power source to the ladder-type electrode, and generating glow discharge in the reaction vessel. MembraneAnd 1 × 10 chlorine ¹⁸ cm ^-3 ~ 8x10 ²⁰ cm ^-3 ContainIt is characterized by that.
[0013]
In the solar cell according to the present invention, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed on a transparent insulating substrate. In the solar cell that makes light incident from the transparent insulating substrate side,
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 1 chlorine.¹⁸cm^-3~ 8x10²⁰cm^-3It is characterized by containing.
[0014]
Another solar cell according to the present invention includes a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode on a transparent insulating substrate. In a solar cell that is sequentially formed and makes light incident from the second transparent electrode side,
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 1 chlorine.¹⁸cm^-3~ 8x10²⁰cm^-3It is characterized by containing.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0016]
FIG. 1 is a schematic view showing a plasma CVD apparatus used for forming a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure in manufacturing a solar cell according to an embodiment described below, and FIG. It is a perspective view which shows the ladder-type electrode for discharge integrated in 1 CVD apparatus.
[0017]
In the grounded reaction vessel 1, a discharge ladder 2 having a structure shown in FIG. An anode 3 containing a heater (not shown) is disposed in the reaction vessel 1 in parallel with the ladder electrode 2 at a desired distance. In such an arrangement of the ladder-type electrode 2 and the anode 3, the facing surfaces thereof are referred to as the front surface and the opposite surface is referred to as the rear surface. The anode 3 has a function of holding a substrate to be processed.
[0018]
The high frequency power source 4 is connected to the ladder-type electrode 2 through the impedance matching unit 5. The gas supply pipe 6 for supplying the source gas is inserted into the reaction vessel 1 so that the tip thereof is located on the back surface of the ladder-type electrode 2. The exhaust pipe 7 is connected to the side surface of the reaction vessel 1 located on the back surface of the anode 3 and the other end is connected to an exhaust member such as a vacuum pump (not shown).
[0019]
(First embodiment)
A method for manufacturing a solar cell in which light is incident from the transparent insulating substrate side according to the present invention will be described with reference to the plasma CVD apparatus shown in FIGS. 1 and 2 described above.
[0020]
(First step)
A first transparent electrode is formed on the transparent insulating substrate.
[0021]
The transparent insulating substrate is made of, for example, blue plate glass that exhibits light transmission.
[0022]
The first transparent electrode is, for example, tin oxide (SnO₂), Made from a metal oxide such as indium tin oxide (ITO). Here, a zinc oxide film (not shown) having a thickness of several tens of nm is formed on the first transparent electrode in order to suppress reduction of the first transparent electrode by hydrogen.
[0023]
(Second step)
The transparent insulating substrate on which the first transparent electrode is formed is held as the workpiece 8 on the anode 3 of the plasma CVD apparatus shown in FIG. 1, and the workpiece 8 is connected to the grounded reaction vessel 1 through the lead. After that, the reaction vessel 1 is evacuated through the exhaust pipe 7 by operating a vacuum pump (not shown). Subsequently, the heater built in the anode 3 is energized to heat the substrate of the workpiece 8 to a desired temperature. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂The p-type impurity gas is introduced through the gas supply pipe 6 to control the inside of the reaction vessel 1 to a predetermined pressure. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 is generated to form a p-type microcrystalline Si layer or a polycrystalline Si layer on the first transparent electrode of the workpiece 8.
[0024]
As the p-type impurity, for example, B₂H₆Etc. can be used.
[0025]
(Third step)
After forming a p-type microcrystalline Si layer or polycrystalline Si layer, the supply of the source gas is stopped and the reaction vessel 1 is evacuated. Subsequently, SiH which is a raw material gas in the reaction vessel 1_FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂Gas is introduced through the gas supply pipe 6 and controlled to a predetermined pressure in the reaction vessel 1. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high-frequency power having a frequency of 60 MHz or more is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5 and the discharge ladder-type electrode 2 Plasma 9 is generated between the workpiece 8 to form an i-type microcrystalline Si layer or polycrystalline Si layer on the p-type microcrystalline Si layer or polycrystalline Si layer of the workpiece 8. .
[0026]
By adding the chlorinated silicon-based compound gas to the raw material gas, the transparent insulating substrate of the object to be processed by the heater of the anode 3 is preferentially (110) under a relatively low temperature heating condition of 120 to 300 ° C. It becomes possible to form an i-type microcrystalline Si layer or polycrystalline Si layer having orientation. If the heating temperature of the transparent insulating substrate is lower than 120 ° C., it may be difficult to form an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation. On the other hand, when the heating temperature of the transparent insulating substrate is higher than 300 ° C., SiH is formed during film formation._FourHydrogen radicals in the plasma derived from the gas diffuse through the p-type microcrystalline Si layer or polycrystalline Si layer, reach the first transparent electrode made of the lower metal oxide, and reduce the metal oxide. Oxygen extraction occurs, resulting in a decrease in light transmittance, resulting in a decrease in photoelectric conversion efficiency, and a p-type impurity in a p-type microcrystalline Si layer or a polycrystalline Si layer diffuses into a pi junction interface, resulting in electrical characteristics. Degradation may occur, leading to a decrease in photoelectric conversion efficiency.
[0027]
The chlorinated silicon-based compound gas is the SiH_FourIt is preferable to supply the reaction vessel 1 with a flow rate ratio of 1 to 80% with respect to the total flow rate of the chlorinated silicon compound gas. When the flow rate ratio of the chlorinated silicon-based compound gas is less than 1%, an i-type microcrystalline Si layer or a polycrystalline Si layer is formed under a relatively low temperature heating condition of 120 to 300 ° C. It becomes difficult to do. On the other hand, when the flow rate ratio of the chlorinated silicon-based compound gas exceeds 80%, the i-type microcrystalline Si layer or the polycrystalline Si layer becomes Cl, Cl₂There is a possibility that the film-forming speed is reduced by etching, and the i-type Si layer becomes amorphous. The flow rate ratio of the chlorinated silicon-based compound gas is more preferably 10% to 40%.
[0028]
By setting the flow rate ratio of the chlorinated silicon-based compound gas to 1 to 80%, chlorine is 1 × 10¹⁸cm^-3~ 8x10²⁰cm^-3An i-type microcrystalline Si layer or a polycrystalline Si layer can be formed. The chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is 1 × 10¹⁸cm^-3If it is less than this, it becomes difficult to improve the (110) preferential orientation in the i-type microcrystalline Si layer or polycrystalline Si layer. On the other hand, the chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is 8 × 10²⁰cm^-3If it exceeds 1, the film quality of the i-type microcrystalline Si layer or polycrystalline Si layer may be deteriorated. The chlorine content in the more preferable i-type microcrystalline Si layer or polycrystalline Si layer is 2 × 10¹⁹cm^-3~ 4x10²⁰cm^{-3 It is.}
The chlorinated silicon compound gas is changed to SiH._FourAnd H₂When mixing with H₂The use of gas diluted with is allowed.
[0029]
The pressure for generating plasma in the reaction vessel is desirably set in the range of 0.5 to 10 Torr, more preferably in the range of 0.5 to 3.0 Torr.
[0030]
(4th process)
After forming the i-type microcrystalline Si layer or polycrystalline Si layer, the supply of the source gas is stopped and the reaction vessel 1 is evacuated. Subsequently, SiH as a raw material gas is contained in the reaction vessel 1._Four, H₂And n-type impurity gas (PH_ThreeEtc.) is introduced through the gas supply pipe 6 and controlled to a predetermined pressure in the reaction vessel 1. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 is generated, and an n-type microcrystalline Si layer or a polycrystalline Si layer is formed on the i-type microcrystalline Si layer or polycrystalline Si layer of the workpiece 8. Thereafter, the object to be processed is taken out from the plasma CVD layer reaction vessel 1, and a second transparent electrode and a back electrode are sequentially formed on the n-type microcrystalline Si layer or polycrystalline Si layer to manufacture a solar cell. . This solar cell is generated by making light such as sunlight enter from the transparent insulating substrate side and performing photoelectric conversion on the microcrystalline Si layer or the polycrystalline Si layer having the pin structure.
[0031]
As the n-type impurity gas, for example, PH_ThreeEtc. can be used.
[0032]
The second transparent electrode is made of, for example, indium tin oxide (ITO) or tin oxide.
[0033]
The back electrode is made of, for example, Al.
[0034]
In the production of the solar cell, the p-type, i-type, and n-type microcrystalline Si layers are sequentially formed from the first transparent electrode side to form a pin structure. However, the n-type, i-type, and p-type microcrystals are formed. A silicon layer or a polycrystalline silicon layer may be sequentially formed to have a nip structure.
[0035]
Further, the arrangement of p, i, n is the same as that of the microcrystalline silicon layer or the polycrystalline silicon layer between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure. An amorphous silicon layer having a pin structure or a nip structure is allowed to be disposed.
[0036]
As described above, according to the first embodiment, the first transparent electrode, the microcrystalline Si layer or the polycrystalline Si layer having the pin structure or the nip structure, the second transparent electrode, and the back electrode are sequentially formed on the transparent insulating substrate, In the manufacture of a solar cell having a structure in which light is incident from the transparent insulating substrate side, a workpiece having the transparent insulating substrate is supported on a support electrode of a plasma CVD apparatus and heated, and SiH_FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂The gas mixture is supplied as a raw material gas from the gas supply means into the reaction vessel, and a glow discharge generating power having a frequency of 60 MHz or more is supplied from the power source to the ladder electrode to cause a glow discharge in the reaction vessel. By generating plasma, a p-type (or n-type) microcrystalline Si layer or a polycrystalline Si layer is formed into an i-type having (110) preferential orientation under a relatively low temperature heating condition of 120 to 300 ° C. A microcrystalline Si layer or a polycrystalline Si layer can be formed.
[0037]
That is, SiH₂Cl₂By using a chlorinated silicon-based gas such as as a component of the source gas, the chlorinated silicon-based gas decomposes in the plasma to generate chlorine, so that the silicon growth surface is covered with chlorine instead of hydrogen. Is possible. Chlorine has a larger atomic size than hydrogen, and is thus hardly taken into the Si layer, and can suppress the generation of secondary nuclei that hinder (110) orientation. As a result, an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation can be formed.
[0038]
Therefore, when forming an i-type microcrystalline Si layer or a polycrystalline Si layer, SiH_FourA hydrogen gas radical derived from a gas diffuses in the p-type (or n-type) microcrystalline Si layer or polycrystalline Si layer, and further includes a first transparent electrode made of a metal oxide such as tin oxide on the lower side. It is possible to suppress the reaction of reaching and reducing. As a result, it is possible to maintain the light transmittance of the first transparent electrode by suppressing the oxygen extraction of the metal oxide.
[0039]
In addition, when an i-type microcrystalline Si layer or a polycrystalline Si layer is formed, a p-type (or ni-junction interface) with a p-type (or n-type) microcrystalline Si layer or polycrystalline Si layer has a p-type (or ni-type interface). Alternatively, since diffusion of n-type impurities can be suppressed, electrical characteristics at the bonding interface can be maintained in a favorable state.
[0040]
As described above, according to the first embodiment, an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation can be formed at a relatively low temperature, and light can be transmitted through the first transparent electrode. And maintain good electrical characteristics at the pi junction interface (or ni junction interface), so that when a light such as sunlight is incident from the transparent insulating substrate side, A solar cell exhibiting conversion efficiency can be manufactured.
[0041]
In addition, the first transparent electrode, the microcrystalline Si layer or polycrystalline Si layer having a pin structure or nip structure, the second transparent electrode, and the back electrode are sequentially formed so that light is incident from the transparent insulating substrate side. In the battery, the amount of chlorine in the i-type microcrystalline Si layer or polycrystalline Si layer is 1 × 10¹⁸~ 8x10²⁰cm^-3Since (110) preferential orientation can be improved, a solar cell exhibiting high photoelectric conversion efficiency can be obtained when light such as sunlight is incident from the transparent insulating substrate side.
[0042]
  Furthermore, the arrangement of p, i, and n is the same as that of the microcrystalline Si layer or the polycrystalline Si layer between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure. By disposing an amorphous silicon layer having a pin structure or a nip structure, a solar cell with higher photoelectric conversion efficiency can be obtained.
[0043]
(Second Embodiment)
A method for manufacturing a solar cell in which light is incident from the second transparent electrode side according to the present invention will be described with reference to the plasma CVD apparatus shown in FIGS. 1 and 2 described above.
[0044]
(First step)
For example, a back electrode made of, for example, Al is formed on a transparent insulating substrate made of blue glass that shows light transmission, and then made of a metal oxide such as tin oxide or indium tin oxide (ITO) on the back electrode. Forming a first transparent electrode.
[0045]
(Second step)
The transparent insulating substrate on which the first transparent electrode is formed is held as the workpiece 8 on the anode 3 of the plasma CVD apparatus shown in FIG. 1, and the workpiece 8 is connected to the grounded reaction vessel 1 through the lead. Thereafter, a vacuum pump (not shown) is operated to evacuate the gas in the reaction vessel 1 through the exhaust pipe 7. Subsequently, the heater built in the anode 3 is energized to heat the substrate of the workpiece 8 to a desired temperature. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And for example PH_ThreeSuch an n-type impurity gas is introduced through the gas supply pipe 6 to control the inside of the reaction vessel 1 to a predetermined pressure. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. In the meantime, plasma 9 is generated to form an n-type microcrystalline Si layer or polycrystalline Si layer on the first transparent electrode of the workpiece 8.
[0046]
(Third step)
After forming the n-type microcrystalline Si layer or polycrystalline Si layer, the supply of the source gas is stopped and the reaction vessel 1 is evacuated. Subsequently, SiH which is a raw material gas in the reaction vessel 1_FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂Gas is introduced through the gas supply pipe 6 and controlled to a predetermined pressure in the reaction vessel 1. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power having a frequency of 60 MHz or more is supplied from the high frequency power source 4 to the discharge ladder type electrode 2 through the impedance matching device 5, so that the discharge ladder type electrode 2 Plasma 9 is generated between the workpiece 8 to form an i-type microcrystalline Si layer or polycrystalline Si layer on the n-type microcrystalline Si layer or polycrystalline Si layer of the workpiece 8. .
[0047]
By adding the chlorinated silicon-based compound gas to the raw material gas, the transparent insulating substrate of the object to be processed by the heater of the anode 3 is preferentially (110) under a relatively low temperature heating condition of 120 to 300 ° C. It becomes possible to form an i-type microcrystalline Si layer or polycrystalline Si layer having orientation. If the heating temperature of the transparent insulating substrate is lower than 120 ° C., it may be difficult to form an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation. On the other hand, when the heating temperature of the transparent insulating substrate is higher than 300 ° C., SiH is formed during film formation._FourHydrogen radicals in the plasma derived from the gas diffuse through the n-type microcrystalline Si layer or polycrystalline Si layer, reach the first transparent electrode made of the lower metal oxide, and reduce the metal oxide. Oxygen extraction occurs, resulting in a decrease in light transmittance, resulting in a decrease in photoelectric conversion efficiency, or an n-type impurity in the n-type microcrystalline Si layer or polycrystalline Si layer diffuses into the ni junction interface, resulting in electrical characteristics. Degradation may occur, leading to a decrease in photoelectric conversion efficiency.
[0048]
The chlorinated silicon-based compound gas is the SiH_FourIt is preferable to supply the reaction vessel 1 with a flow rate ratio of 1 to 80% with respect to the total flow rate of the chlorinated silicon compound gas. When the flow rate ratio of the chlorinated silicon-based compound gas is less than 1%, an i-type microcrystalline Si layer or polycrystalline Si layer having a good film quality under a relatively low temperature heating condition of 120 to 300 ° C. It becomes difficult to do. On the other hand, if the flow rate ratio of the chlorinated silicon-based compound gas exceeds 80%, the i-type microcrystalline Si or polycrystalline Si layer becomes Cl, Cl₂There is a possibility that the film-forming speed is reduced by etching, and the i-type Si layer becomes amorphous. The flow rate ratio of the chlorinated silicon-based compound gas is more preferably 10% to 40%.
[0049]
By setting the flow rate ratio of the chlorinated silicon-based compound gas to 1 to 80%, chlorine is 1 × 10¹⁸cm^-3~ 8x10²⁰cm^-3An i-type microcrystalline Si layer or a polycrystalline Si layer can be formed. The chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is 1 × 10¹⁸cm^-3If it is less than this, it becomes difficult to improve the (110) preferential orientation in the i-type microcrystalline Si layer or polycrystalline Si layer. On the other hand, the chlorine content in the i-type microcrystalline Si layer or polycrystalline Si layer is 8 × 10²⁰cm^-3If it exceeds 1, the film quality of the i-type microcrystalline Si layer or polycrystalline Si layer may be deteriorated. The chlorine content in the more preferable i-type microcrystalline Si layer or polycrystalline Si layer is 2 × 10¹⁹cm^-3~ 4x10²⁰cm^{-3 It is.}
The chlorinated silicon compound gas is changed to SiH._FourAnd H₂When mixing with H₂Allow to dilute with.
[0050]
The pressure for generating plasma in the reaction vessel is desirably set in the range of 0.5 to 10 Torr, more preferably in the range of 0.5 to 3.0 Torr.
[0051]
The high-frequency power supplied from the high-frequency power source to the discharge ladder electrode preferably has a frequency of 60 MHz or more.
[0052]
(4th process)
After forming the i-type microcrystalline Si layer or polycrystalline Si layer, the supply of the source gas is stopped and the reaction vessel 1 is evacuated. Subsequently, SiH, H, and B, for example, which are source gases, are contained in the reaction vessel 1₂H₆Such a p-type impurity gas is introduced through the gas supply pipe 6 and controlled to a predetermined pressure in the reaction vessel 1. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high-frequency power is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, whereby the discharge ladder-type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 is generated to form a p-type microcrystalline Si layer or polycrystalline Si layer on the i-type microcrystalline Si layer or polycrystalline Si layer of the workpiece 8. Thereafter, the object to be processed is taken out of the plasma CVD layer reaction vessel 1 and is made of a metal oxide such as tin oxide or indium tin oxide (ITO) on the p-type microcrystalline Si layer or polycrystalline Si layer. A second transparent electrode is formed to manufacture a solar cell. This solar cell is generated by making light such as sunlight enter from the second transparent electrode side and photoelectrically converting it in the microcrystalline Si layer or polycrystalline Si layer having the pin structure.
[0053]
In the production of the solar cell, n-type, i-type, and p-type microcrystalline Si layers are sequentially formed from the first transparent electrode side to form a nip structure. However, p-type, i-type, and n-type microcrystals are formed. A Si layer or a polycrystalline Si layer may be sequentially formed to have a pin structure.
[0054]
In addition, the arrangement of p, i, and n is the same as that of the microcrystalline Si layer or the polycrystalline Si layer between the microcrystalline Si layer or polycrystalline Si layer having the nip structure or the pin structure and the second transparent electrode. An amorphous silicon layer having a nip structure or a pin structure is allowed to be disposed.
[0055]
As described above, according to the second embodiment, the back electrode, the first transparent electrode, the microcrystalline Si layer or the polycrystalline Si layer having the nip structure or the pin structure, and the second transparent electrode are sequentially formed on the transparent insulating substrate, In manufacturing a solar cell having a structure in which light is incident from the second transparent electrode side, a workpiece having the transparent insulating substrate is supported on a support electrode of a plasma CVD apparatus and heated, and SiH_FourAnd SiH₂Cl₂, SiHCl_ThreeAnd SiCl_FourAt least one chlorinated silicon compound gas selected from H and H₂A gas mixture is supplied as a raw material gas from the gas supply means into the reaction vessel, and a glow discharge generating power having a frequency of 60 MHz or more is supplied from the power source to the ladder electrode to cause a glow discharge in the reaction vessel. By generating plasma, an action similar to that of the first embodiment described above is performed on a n-type (or p-type) microcrystalline Si layer or a polycrystalline Si layer under a relatively low temperature heating condition of 120 to 300 ° C. Thus, an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation can be formed.
[0056]
Therefore, when forming an i-type microcrystalline Si layer or a polycrystalline Si layer, SiH_FourHydrogen radicals in the plasma derived from the gas diffuse through the n-type microcrystalline Si layer or polycrystalline Si layer, and reach the first transparent electrode made of a metal oxide such as tin oxide on the lower side to be reduced. The reaction can be suppressed. As a result, it is possible to maintain the light transmittance of the first transparent electrode by suppressing the oxygen extraction of the metal oxide.
[0057]
In addition, when an i-type microcrystalline Si layer or a polycrystalline Si layer is formed, an n-type (or pi-junction interface) with an n-type (or pi-junction interface) with an n-type (or p-type) microcrystalline Si layer or a polycrystalline Si layer is used. Alternatively, the diffusion of p-type impurities can be suppressed, so that electrical characteristics at the bonding interface can be maintained in a favorable state.
[0058]
As described above, according to the second embodiment, an i-type microcrystalline Si layer or polycrystalline Si layer having (110) preferential orientation can be formed at a relatively low temperature, and light can be transmitted through the first transparent electrode. And the electrical characteristics at the ni junction interface (or pi junction interface) can be maintained in a good state. Therefore, when light such as sunlight is incident from the second transparent electrode side, A solar cell exhibiting conversion efficiency can be manufactured.
[0059]
Further, a back electrode, a first transparent electrode, a microcrystalline Si layer or a polycrystalline Si layer having a nip structure or a pin structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, and light is transmitted from the second transparent electrode side. In the solar cell having a structure in which the incident light is incident, the amount of chlorine in the i-type microcrystalline Si layer or the polycrystalline Si layer is 1 × 10¹⁸~ 8x10²⁰cm^-3(110) Since the preferred orientation can be improved, a solar cell exhibiting high photoelectric conversion efficiency can be obtained when light such as sunlight is incident from the second transparent electrode side.
[0060]
Further, the arrangement of p, i, n is the same as that of the microcrystalline Si layer or the polycrystalline Si layer between the microcrystalline Si layer or polycrystalline Si layer having the nip structure or the pin structure and the second transparent electrode. By disposing an amorphous silicon layer having a nip structure or a pin structure, a solar cell with higher photoelectric conversion efficiency can be obtained.
[0061]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0062]
Example 1
In Example 1, a manufacturing process of a solar cell in which light is incident from the transparent insulating substrate side and the pin structure is made of microcrystalline Si will be described with reference to FIG.
[0063]
First, tin oxide (SnO) is formed on a transparent insulating substrate 11 made of blue glass having light transmission.₂The 1st transparent electrode 12 which consists of this was formed.
[0064]
Next, the transparent insulating substrate 11 on which the transparent electrode 12 is formed is held as the object to be processed 8 on the anode 3 in the reaction container 1 for p-layer deposition in the plasma CVD apparatus shown in FIG. After the object 8 is connected to the grounded reaction vessel 1 through a lead, a vacuum pump (not shown) is operated and the inside of the reaction vessel 1 through the exhaust pipe 7 is 1 × 10^{− 8}The evacuation was performed below Torr. Subsequently, the heater built in the anode 3 was energized to heat the substrate of the workpiece 8 to a temperature of 160 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And B₂H₆Was introduced through the gas supply pipe 6 and the pressure in the reaction vessel 1 was controlled to 500 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power having a frequency of 100 MHz is supplied from the high-frequency power source 4 to the ladder-type electrode 2 for discharge through the impedance matching device 5, so Plasma 9 was generated between the processed objects 8, and a p-type microcrystalline Si layer 13 having a thickness of 30 nm was formed on the first transparent electrode 12 of the processed object 8.
[0065]
Subsequently, after forming the p-type microcrystalline Si layer 13, the supply of the source gas was stopped, and the inside of the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for i-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 190 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_FourAnd SiH₂Cl₂And H₂Was introduced through the gas supply pipe 6 and then the pressure in the reaction vessel 1 was controlled to 2 Torr. At this time, the amount of each gas is SiH._Four: 3-7 sccm, SiH₂Cl₂(1% hydrogen dilution): 50-200 sccm, H₂: 100 to 250 sccm. SiH₂Cl₂Was in the range of 10 to 40% of the flow rate of the total Si gas. After introducing the raw material gas, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the frequency of 100 MHz, 70 mW / cm is applied to the discharge ladder electrode 2 from the high frequency power source 4 through the impedance matching unit 5.²Plasma was generated by supplying high-frequency power of 1 to form an i-type microcrystalline Si layer 14 having a thickness of 1500 nm on the p-type microcrystalline Si layer 13. This i-type microcrystalline Si layer 14 contains 6 × 10 chlorine.¹⁹cm^-3Contained.
[0066]
Next, after forming the i-type microcrystalline Si layer 14, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for n-layer film formation, and set in the same procedure. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 160 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas SiH is introduced into the reaction vessel 1._Four, H₂And PH_ThreeWas introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 was controlled to a pressure of 700 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 was generated, and an n-type microcrystalline Si layer 15 having a thickness of 30 nm was formed on the i-type microcrystalline Si layer 14 of the workpiece 8. Thereafter, the object to be processed is taken out from the plasma CVD layer reaction vessel 1, and a second transparent electrode 16 made of indium oxide (ITO) and a back electrode 17 made of Al are sequentially formed on the n-type microcrystalline Si layer 15. The solar cell shown in FIG. 3 was manufactured.
[0067]
(Comparative Example 1)
SiH which is a source gas in the reaction vessel 1_Four(Flow rate: 4-8 sccm) and H₂(Flow rate: 250 to 350 sccm) is introduced through the gas supply pipe 6, the pressure in the reaction vessel 1 is controlled to 2 Torr, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the impedance matching device is supplied from the high frequency power source 4. 5 to discharge ladder electrode 2 at a frequency of 100 MHz and 70 mW / cm.²A solar cell was produced in the same manner as in Example 1 except that plasma was generated by supplying high-frequency power and an i-type microcrystalline Si layer 14 having a thickness of 1500 nm was formed on the p-type microcrystalline Si layer. Manufactured.
[0068]
The (110) orientation ratio of the i-type microcrystalline Si layer formed in Example 1 and Comparative Example 1 was examined. The results are shown in Table 1 below.
[0069]
[Table 1]

[0070]
As apparent from Table 1, SiH₂Cl₂The i-type microcrystalline Si layer of Example 1 formed by using a raw material gas added with a flow rate ratio of 10 to 40% with respect to the flow rate of the total Si gas is SiH.₂Cl₂SiH without adding_FourAnd H₂It can be seen that the (110) orientation ratio shows a value of 29 which is 5 times or more as compared with the i-type microcrystalline Si layer of Comparative Example 1 formed using a source gas consisting of
[0071]
Further, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / cm) was applied to the solar cells of Example 1 and Comparative Example 1.²Sample temperature: room temperature) was incident from the transparent insulating substrate side, and the power generation characteristics were evaluated. The result is shown in FIG.
[0072]
As is clear from FIG. 4, the solar cell of Example 1 has an improved short circuit current compared to the solar cell of Comparative Example 1. This is because the (110) orientation ratio of the i-type microcrystalline Si layer constituting the solar cell of Example 1 was improved.
[0073]
(Example 2)
In Example 2, a manufacturing process of a solar cell in which light is incident from the transparent insulating substrate side and the pin structure is made of polycrystalline Si will be described with reference to FIG.
[0074]
First, the first transparent electrode 12 made of tin oxide was formed on the transparent insulating substrate 11 made of blue plate glass having light transmission.
[0075]
Next, the transparent insulating substrate 11 on which the transparent electrode 12 is formed is held as the workpiece 8 on the anode 3 in the reaction container 1 for p-layer deposition in the plasma CVD apparatus shown in FIG. 8 is connected to the grounded reaction vessel 1 through a lead, and then a vacuum pump (not shown) is operated to evacuate the reaction vessel 1 through the exhaust pipe 7 by 1 × 10^-8The evacuation was performed below Torr. Subsequently, the heater built in the anode 3 was energized to heat the substrate of the workpiece 8 to a temperature of 180 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And B₂H₆Was introduced through the gas supply pipe 6 and the pressure in the reaction vessel 1 was controlled to 500 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power having a frequency of 100 MHz is supplied from the high-frequency power source 4 to the ladder-type electrode 2 for discharge through the impedance matching device 5, so Plasma 9 was generated between the processed objects 8, and a p-type polycrystalline Si layer 18 having a thickness of 300 nm was formed on the first transparent electrode 12 of the processed object 8.
[0076]
Subsequently, after forming the p-type polycrystalline Si layer 18, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for i-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 8 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 210 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_FourAnd SiH₂Cl₂And H₂Was introduced through the gas supply pipe 6, and the pressure in the reaction vessel 1 was controlled at 1.0 Torr. At this time, the amount of each gas is SiH._Four: 5-10 sccm, SiH₂Cl₂(1% hydrogen dilution): 100-200 sccm, H₂: 100-200 sccm. SiH₂Cl₂Was in the range of 10 to 30% in flow rate ratio with respect to the flow rate of the total Si gas. After introducing the raw material gas, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the frequency is set to 100 MHz and 100 mW / cm from the high frequency power source 4 to the discharge ladder electrode 2 through the impedance matching unit 5.²Plasma was generated by supplying a high-frequency power of 1, and an i-type polycrystalline Si layer 19 having a thickness of 1500 nm was formed on the p-type polycrystalline Si layer 18. This i-type polycrystalline Si layer 18 contains 4 × 10 chlorine.¹⁹cm^-3Contained.
[0077]
Next, after forming the i-type polycrystalline Si layer 19, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for n-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized to heat the substrate of the workpiece 8 to 180 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas SiH is introduced into the reaction vessel 1._Four, H₂And PH_ThreeWas introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 was controlled to a pressure of 700 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 was generated, and an n-type polycrystalline Si layer 20 having a thickness of 30 nm was formed on the i-type polycrystalline Si layer 19 of the workpiece 8. Thereafter, the object to be processed is taken out from the plasma CVD layer reaction vessel 1, and a second transparent electrode 16 made of indium oxide and a back electrode 17 made of Al are sequentially formed on the n-type polycrystalline Si layer 20 as shown in FIG. The solar cell shown in FIG.
[0078]
As a result of examining the (110) orientation ratio of the i-type polycrystalline Si layer formed in Example 2, the value of 29 was the same as in Example 1.
[0079]
Moreover, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / cm) was applied to the solar cell of Example 2.², Irradiation temperature: room temperature) was incident from the transparent insulating substrate side, and power generation characteristics were evaluated. As a result, a large short-circuit current similar to that in Example 1 was obtained.
[0080]
(Example 3)
In Example 3, a manufacturing process of a solar cell in which light is incident from the transparent insulating substrate side, the pin structure is made of microcrystalline Si, and the tandem structure is described with reference to FIG.
[0081]
First, the first transparent electrode 12 made of tin oxide was formed on the transparent insulating substrate 11 made of blue plate glass having light transmission.
[0082]
Next, the transparent insulating substrate 11 on which the transparent electrode 12 is formed is held as the workpiece 8 on the anode 3 in the reaction vessel 1 in the plasma CVD apparatus shown in FIG. 1, and the workpiece 8 is grounded through the lead. After connecting to the reaction vessel 1, a vacuum pump (not shown) is operated and the inside of the reaction vessel 1 is passed through the exhaust pipe 7 by 1 × 10^-8The evacuation was performed below Torr. Subsequently, the heater built in the anode 3 was energized to heat the substrate of the workpiece 8 to a temperature of 130 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And B₂H₆Was introduced through the gas supply pipe 6 and the pressure inside the reaction vessel 1 was controlled to 100 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high-frequency power having a frequency of 13.56 MHz is supplied from the high-frequency power source 4 to the discharge ladder-type electrode 2 through the impedance matching device 5, thereby Plasma 9 was generated between the workpieces 8 to form a 30 nm thick p-type amorphous Si layer 31 on the first transparent electrode 12 of the workpiece 8.
[0083]
Next, after forming the p-type amorphous Si layer 31, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for i-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 160 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four(Flow rate: 50 sccm) and H₂After introducing (flow rate: 50 sccm) through the gas supply pipe 6, the pressure in the reaction vessel 1 was controlled to 100 mTorr. After introducing the raw material gas, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the high frequency power source 4 is passed through the impedance matching unit 5 to the discharge ladder electrode 2 at a frequency of 60 MHz and 200 mW / cm.²Plasma was generated by supplying a high-frequency power, and an i-type amorphous Si layer 32 having a thickness of 300 nm was formed on the p-type amorphous Si layer 31.
[0084]
Subsequently, after forming the i-type amorphous Si layer 32, the supply of the source gas was stopped, and the inside of the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for n-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 130 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas SiH is introduced into the reaction vessel 1._Four, H₂And PH_ThreeWas introduced through the gas supply pipe 6 and the pressure inside the reaction vessel 1 was controlled to 100 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 was generated, and an n-type amorphous Si layer 33 having a thickness of 40 nm was formed on the i-type amorphous Si layer 32 of the workpiece 8.
[0085]
Next, on the n-type amorphous Si layer 33, the second method comprising the p-type microcrystalline Si layer 13, the i-type microcrystalline Si layer 14, the n-type microcrystalline Si layer 15, and indium oxide by the same method as in the first embodiment. A transparent electrode 16 and a back electrode 17 made of Al were sequentially formed to manufacture a tandem solar cell shown in FIG.
[0086]
Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm) in the solar cell of Example 3², Irradiation temperature: room temperature) was incident from the transparent insulating substrate side, and power generation characteristics were evaluated. As a result, a short circuit current value of 1.10 (relative value) was obtained as compared with the case where Comparative Example 1 was applied to the tandem.
[0087]
Example 4
In Example 4, a manufacturing process of a solar cell in which light is incident from the transparent insulating substrate side and the pin structure is made of polycrystalline Si and has a tandem structure will be described with reference to FIG.
[0088]
First, the first transparent electrode 12 made of tin oxide was formed on the transparent insulating substrate 11 made of blue plate glass having light transmission. Subsequently, a p-type amorphous Si layer 31, an i-type amorphous Si layer 32, and an n-type amorphous Si layer 33 were sequentially formed on the transparent electrode 12 in the same manner as in Example 3. Subsequently, on the n-type amorphous Si layer 33, the second method comprising the p-type polycrystalline Si layer 18, the i-type polycrystalline Si layer 19, the n-type polycrystalline Si layer 20, and indium oxide by the same method as in Example 2 described above. A transparent electrode 16 and a back electrode 17 made of Al were sequentially formed to manufacture a tandem solar cell shown in FIG.
[0089]
Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm) for the solar cell of Example 4², Irradiation temperature: room temperature) was incident from the transparent insulating substrate side, and power generation characteristics were evaluated. As a result, a large short-circuit current value was obtained as in Example 3.
[0090]
(Example 5)
In Example 5, a manufacturing process of a solar cell in which light enters from the second transparent electrode side and the nip structure is made of microcrystalline Si will be described with reference to FIG.
[0091]
First, a back electrode 42 made of Al and a first transparent electrode 43 made of zinc oxide (ZnO) were formed on a transparent insulating substrate 41 made of blue plate glass having light transmission.
[0092]
Next, the transparent insulating substrate 41 on which the transparent electrode 43 is formed is held on the anode 3 in the reaction vessel 1 for n-layer deposition in the plasma CVD apparatus shown in FIG. After the object 8 is connected to the grounded reaction vessel 1 through a lead, a vacuum pump (not shown) is operated and the inside of the reaction vessel 1 through the exhaust pipe 7 is 1 × 10^-8The evacuation was performed below Torr. Subsequently, the heater built in the anode 3 was energized to heat the substrate of the workpiece 8 to a temperature of 160 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And PH_ThreeWas introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 was controlled to a pressure of 700 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power having a frequency of 100 MHz is supplied from the high-frequency power source 4 to the ladder-type electrode 2 for discharge through the impedance matching unit 5 and the ladder-type electrode 2 for discharge and the covered electrode. Plasma 9 was generated between the processed objects 8, and an n-type microcrystalline Si layer 44 having a thickness of 30 nm was formed on the first transparent electrode 43 of the processed object 8.
[0093]
Next, after forming the n-type microcrystalline Si layer 44, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for i-layer film formation, and set in the same procedure as the above film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 190 ° C. After the heating temperature by the heater is sufficiently stabilized, the reaction gas in the reaction vessel 1 is SiH which is a raw material gas._FourAnd SiH₂Cl₂And H₂Was introduced through the gas supply pipe 6, and the pressure in the reaction vessel 1 was controlled at 2.0 Torr. At this time, the amount of each gas is SiH._Four: 3-7 sccm, SiH₂Cl₂(1% hydrogen dilution): 50-250 sccm, H₂: 100 to 250 sccm. SiH₂Cl₂Was in the range of 10 to 40% of the flow rate of the total Si gas. After the source gas is introduced, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then high frequency power with a frequency of 100 MHz and 10 W is supplied from the high frequency power source 4 to the discharge ladder electrode 2 through the impedance matching unit 5. Plasma was generated, and an i-type microcrystalline Si layer 45 having a thickness of 1500 nm was formed on the n-type microcrystalline Si layer 44. This i-type microcrystalline Si layer 45 contains 6 × 10 chlorine.¹⁹cm^-3Contained.
[0094]
Next, after forming the i-type microcrystalline Si layer 45, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for p-layer film formation, and set in the same procedure as that for film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 160 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas SiH is introduced into the reaction vessel 1._Four, H₂And B₂H₆Was introduced through the gas supply pipe 6 and the pressure in the reaction vessel 1 was controlled to 500 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this time, plasma 9 was generated, and a p-type microcrystalline Si layer 46 having a thickness of 30 nm was formed on the i-type microcrystalline Si layer 45 of the workpiece 8. Thereafter, the object to be processed was taken out from the plasma CVD layer reaction vessel 1, and a second transparent electrode 47 made of indium oxide was formed on the p-type microcrystalline Si layer 46 to manufacture the solar cell shown in FIG.
[0095]
As a result of examining the (110) orientation ratio of the i-type microcrystalline Si layer formed in Example 5, the value of 29 was the same as in Example 1.
[0096]
Moreover, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / cm) was applied to the solar cell of Example 5.², Irradiation temperature: room temperature) was incident from the second transparent electrode side, and power generation characteristics were evaluated. As a result, a large short-circuit current similar to that in Example 1 was obtained.
[0097]
(Example 6)
In Example 6, a manufacturing process of a solar cell in which light enters from the second transparent electrode side and the nip structure is made of polycrystalline Si will be described with reference to FIG.
[0098]
First, a back electrode 42 made of Al and a first transparent electrode 43 made of zinc oxide (ZnO) were formed on a transparent insulating substrate 41 made of blue plate glass having light transmission.
[0099]
Next, the transparent insulating substrate 41 on which the transparent electrode 43 is formed is held on the anode 3 in the reaction vessel 1 for n-layer deposition in the plasma CVD apparatus shown in FIG. After the object 8 is connected to the grounded reaction vessel 1 through a lead, a vacuum pump (not shown) is operated and the inside of the reaction vessel 1 through the exhaust pipe 7 is 1 × 10^-7The evacuation was performed below Torr. Subsequently, the heater built in the anode 3 was energized to heat the substrate of the workpiece 8 to a temperature of 180 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_Four, H₂And PH_ThreeWas introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 was controlled to a pressure of 700 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, high-frequency power having a frequency of 100 MHz is supplied from the high-frequency power source 4 to the ladder-type electrode 2 for discharge through the impedance matching unit 5 and the ladder-type electrode 2 for discharge and the covered electrode. Plasma 9 was generated between the processed objects 8, and an n-type polycrystalline Si layer 48 having a thickness of 300 nm was formed on the first transparent electrode 43 of the processed object 8.
[0100]
Next, after forming the n-type polycrystalline Si layer 48, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction vessel 1 for i-layer deposition and set in the same manner as the deposition of the n-type microcrystalline Si layer 13. 1 × 10^-7After evacuating below Torr, the heater 8 built in the anode 3 was energized, and the substrate of the workpiece 8 was heated to 210 ° C. After the heating temperature by the heater is sufficiently stabilized, SiH as a raw material gas is placed in the reaction vessel 1_FourAnd SiH₂Cl₂And H₂Was introduced through the gas supply pipe 6, and the pressure in the reaction vessel 1 was controlled at 1.0 Torr. At this time, the amount of each gas is SiH._Four: 5-10 sccm, SiH₂Cl₂(1% hydrogen dilution): 100-200 sccm, H₂: 100-200 sccm. SiH₂Cl₂Was in the range of 10 to 30% in flow rate ratio with respect to the flow rate of the total Si gas. After introducing the raw material gas, the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, and then the frequency of 100 MHz, 70 mW / cm is applied to the discharge ladder electrode 2 from the high frequency power source 4 through the impedance matching unit 5.²Plasma was generated by supplying a high frequency power of 1, and an i-type polycrystalline Si layer 49 having a thickness of 1500 nm was formed on the n-type polycrystalline Si layer 48. This i-type polycrystalline Si layer 49 contains 4 × 10 chlorine.¹⁹cm^-3Contained.
[0101]
Next, after forming the i-type polycrystalline Si layer 49, the supply of the source gas was stopped, and the reaction vessel 1 was evacuated. Subsequently, the workpiece 8 was moved into the reaction container 1 for p-layer film formation, and set in the same procedure as that for film formation. 1 × 10^-7After evacuating below Torr, the heater 3 built in the anode 3 was energized to heat the substrate of the workpiece 8 to 180 ° C. After the heating temperature by the heater is sufficiently stabilized, the raw material gas SiH is introduced into the reaction vessel 1._Four, H₂And B₂H₆Was introduced through the gas supply pipe 6, and the inside of the reaction vessel 1 was controlled to a pressure of 700 mTorr. After the temperature and pressure in the reaction vessel 1 are sufficiently stabilized, the high frequency power is supplied from the high frequency power source 4 through the impedance matching device 5 to the discharge ladder type electrode 2, whereby the discharge ladder type electrode 2 and the workpiece 8 are processed. During this period, plasma 9 was generated, and a p-type polycrystalline Si layer 50 having a thickness of 30 nm was formed on the i-type polycrystalline Si layer 49 of the workpiece 8. Thereafter, the object to be processed was taken out from the plasma CVD layer reaction vessel 1, and a second transparent electrode 47 made of indium oxide was formed on the p-type polycrystalline Si layer 50 to manufacture the solar cell shown in FIG.
[0102]
As a result of examining the (110) orientation ratio of the i-type polycrystalline Si layer formed in Example 6, a value of 29 similar to that in Example 1 was shown.
[0103]
Moreover, simulated solar light (spectrum: AM1.5, irradiation intensity: 100 mW / cm) was applied to the solar cell of Example 6.², Irradiation temperature: room temperature) was incident from the second transparent electrode side, and power generation characteristics were evaluated. As a result, a large short-circuit current similar to that in Example 1 was obtained.
[0104]
(Example 7)
In Example 7, a manufacturing process of a solar cell in which light enters from the second transparent electrode side, the nip structure is made of microcrystalline Si, and has a tandem structure will be described with reference to FIG.
[0105]
First, a back electrode 42 made of Al and a first transparent electrode 43 made of tin oxide were formed on a transparent insulating substrate 41 made of blue plate glass having light transmission. Subsequently, an n-type microcrystalline Si layer 43, an i-type microcrystalline Si layer 44, and a p-type microcrystalline Si layer 45 were sequentially formed on the second transparent electrode 43 by the same method as in Example 5. Subsequently, an n-type amorphous Si layer 51, an i-type amorphous Si layer 52 and a p-type amorphous Si layer 53 are sequentially formed on the p-type microcrystalline Si layer 45 by the same method as in the third embodiment, and further made of indium oxide. The second transparent electrode 47 was formed to manufacture a tandem solar cell shown in FIG.
[0106]
Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm) in the solar cell of Example 7², Irradiation temperature: room temperature) was incident from the second transparent electrode side, and power generation characteristics were evaluated. As a result, a short circuit current value of 1.10 (relative value) was obtained as compared with the case where Comparative Example 1 was applied to the tandem.
[0107]
(Example 8)
In Example 8, a manufacturing process of a solar cell in which light is incident from the transparent insulating substrate side and the nip structure is made of polycrystalline Si and has a tandem structure will be described with reference to FIG.
[0108]
First, a back electrode 42 made of Al and a first transparent electrode 43 made of tin oxide were formed on a transparent insulating substrate 41 made of blue plate glass having light transmission. Subsequently, an n-type polycrystalline Si layer 48, an i-type polycrystalline Si layer 49, and a p-type polycrystalline Si layer 50 were sequentially formed on the second transparent electrode 43 by the same method as in Example 6. Subsequently, an n-type amorphous Si layer 51, an i-type amorphous Si layer 52, and a p-type amorphous Si layer 53 are sequentially formed on the p-type polycrystalline Si layer 50 by the same method as in Example 3, and further made of indium oxide. The second transparent electrode 47 was formed to manufacture a tandem solar cell shown in FIG.
[0109]
Simulated sunlight (spectrum: AM1.5, irradiation intensity: 100 mW / cm) for the solar cell of Example 8², Irradiation temperature: room temperature) was incident from the second transparent electrode side, and power generation characteristics were evaluated. As a result, a large short-circuit current value was obtained as in Example 7.
[0110]
【The invention's effect】
As described above in detail, according to the present invention, the first transparent electrode, the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, the second transparent electrode, and the back electrode are sequentially formed on the transparent insulating substrate. In the production of a solar cell having a structure in which light is incident from the transparent insulating substrate side, at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer is formed at a lower temperature and at a lower cost than in the prior art. By doing so, the i-type microcrystalline silicon layer or the polycrystalline silicon layer is (110) without causing a decrease in light transmittance of the first transparent electrode and a deterioration in electrical characteristics at the pi junction interface or the ni junction interface. It is possible to provide a method of manufacturing a solar cell that can be preferentially oriented and, in turn, has improved power generation characteristics such as short circuit current.
[0111]
According to the present invention, a back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on the transparent insulating substrate, and the second electrode In the production of a solar cell having a structure in which light is incident from the transparent electrode side, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer is formed at a lower temperature and at a lower cost than in the prior art. (110) preferentially orienting the i-type microcrystalline silicon layer or polycrystalline silicon layer without reducing the light transmittance of the transparent electrode and deteriorating the electrical characteristics at the pi junction interface or the ni junction interface. Therefore, it is possible to provide a method for manufacturing a solar cell with improved power generation characteristics such as short-circuit current.
[0112]
Furthermore, according to the present invention, the microcrystalline silicon layer or the polycrystalline silicon layer having a pin structure including the i-type microcrystalline silicon layer or the polycrystalline silicon layer exhibiting the (110) preferential orientation is provided, and the A solar cell with improved power generation characteristics can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a plasma CVD apparatus for producing a solar cell of the present invention.
FIG. 2 is a plan view of a discharge ladder electrode.
FIG. 3 is a cross-sectional view showing the structure of a solar cell in Example 1 of the present invention.
FIG. 4 is a characteristic diagram showing short circuit currents of solar cells in Example 1 and Comparative Example 1 of the present invention.
FIG. 5 is a cross-sectional view showing the structure of a solar cell in Example 2 of the present invention.
FIG. 6 is a cross-sectional view showing the structure of a solar cell in Example 3 of the present invention.
7 is a cross-sectional view showing the structure of a solar cell in Example 4 of the present invention. FIG.
FIG. 8 is a cross-sectional view showing the structure of a solar cell in Example 5 of the present invention.
FIG. 9 is a cross-sectional view showing the structure of a solar cell in Example 6 of the present invention.
FIG. 10 is a cross-sectional view showing the structure of a solar cell in Example 7 of the present invention.
FIG. 11 is a cross-sectional view showing the structure of a solar cell in Example 8 of the present invention.
FIG. 12 is a cross-sectional view showing the structure of a conventional solar cell.
FIG. 13 is a cross-sectional view for explaining problems in a conventional solar cell manufacturing process.
FIG. 14 is a cross-sectional view for explaining another problem in the manufacturing process of a conventional solar cell.
[Explanation of symbols]
1 ... reaction vessel,
2 ... Ladder electrode for discharge,
3 ... Anode,
4 ... High frequency power supply,
5. Matching unit,
6 ... gas supply pipe,
7 ... exhaust pipe,
8 ...
9 ... Plasma,
11, 41 ... Transparent insulating substrate,
12, 42 ... 1st transparent electrode,
13, 46 ... p-type microcrystalline Si layer,
14, 45 ... i-type microcrystalline Si layer,
15, 44 ... n-type microcrystalline Si layer,
16, 47 ... second transparent electrode,
17, 42 ... back electrode,
18, 50 ... p-type polycrystalline Si layer,
19, 49 ... i-type polycrystalline Si layer,
20, 48 ... n-type polycrystalline Si layer,
31, 53... P-type amorphous Si layer,
32, 52 ... i-type amorphous Si layer,
33, 51 ... n-type amorphous Si layer.

Claims (15)

A first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed on the transparent insulating substrate, and the transparent insulating substrate side When manufacturing solar cells that make light incident from
A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging the gas in the reaction vessel, a discharge ladder electrode disposed in the reaction vessel, and A power supply for supplying glow discharge generating power to the discharge ladder electrode, and a support electrode that is disposed in parallel with the discharge ladder electrode in the reaction vessel in parallel with the heater for heating. Using a CVD device,
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer has a transparent insulating substrate on the support electrode of the CVD apparatus. heated by supporting the processed product, the chlorinated silicon of the SiH ₄ and SiH ₂ Cl _2, SiHCl ₃ and at least one chlorinated silicon compound gas and a gas mixture of H ₂ is selected from SiCl ₄ as the source gas Ladder type gas is supplied from the gas supply means into the reaction vessel so that the system compound gas is in the range of 1 to 80% with respect to the total flow rate of the SiH ₄ and the chlorinated silicon compound gas. A plasma is generated by supplying glow discharge generating high frequency power having a frequency of 60 MHz or more to the electrode to cause glow discharge in the reaction vessel. Method of manufacturing a solar cell formed as a film, and characterized that you containing chlorine ^{1 × 10 18 cm -3 ~8 ×} 10 20 cm -3 by the.   Further, the pin having the same arrangement of p, i, n as the microcrystalline silicon layer or the polycrystalline silicon layer between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure. 2. The method of manufacturing a solar cell according to claim 1, wherein an amorphous silicon layer having a structure or a nip structure is disposed. A back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, and the second transparent electrode side When manufacturing solar cells that make light incident from
A reaction vessel, a gas supply means for supplying a raw material gas to the reaction vessel, a discharge means for discharging the gas in the reaction vessel, a discharge ladder electrode disposed in the reaction vessel, and A power supply for supplying glow discharge generating high-frequency power to the discharge ladder-type electrode, and a support electrode that is disposed in parallel with the discharge ladder-type electrode in the reaction vessel and is provided in parallel with the heater for heating. Use a CVD device with
Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer has a transparent insulating substrate as a support electrode of the CVD apparatus. heated by supporting the processed product, the chlorinated silicon of the SiH ₄ and SiH ₂ Cl _2, SiHCl ₃ and at least one chlorinated silicon compound gas and a gas mixture of H ₂ is selected from SiCl ₄ as the source gas Ladder type gas is supplied from the gas supply means into the reaction vessel so that the system compound gas is in the range of 1 to 80% of the total flow rate of the SiH ₄ and the chlorinated silicon compound gas. By supplying glow discharge generating power having a frequency of 60 MHz or more to the electrode to cause glow discharge in the reaction vessel to generate plasma. Are membrane made Ri, and manufacturing method of a solar cell which is characterized that you containing chlorine ^{1 × 10 18 cm -3 ~8 ×} 10 20 cm -3.   Further, the pin having the same arrangement of p, i, n as the microcrystalline silicon layer or the polycrystalline silicon layer between the microcrystalline silicon layer or polycrystalline silicon layer having the pin structure or the nip structure and the second transparent electrode. 4. The method for manufacturing a solar cell according to claim 3, wherein an amorphous silicon layer having a structure or a nip structure is disposed.   4. The solar cell according to claim 1, wherein at least the i-type microcrystalline silicon layer or polycrystalline silicon layer is heated to a temperature of 120 to 300 ° C. by a heater of the support electrode. 5. Production method.   4. The solar cell according to claim 1, wherein at least the i-type microcrystalline silicon layer or polycrystalline silicon layer is heated to a temperature of 160 to 210 ° C. by a heater of the support electrode. 5. Production method. The chlorinated silicon-based compound gas is the SiH _Four 4. The method for manufacturing a solar cell according to claim 1, wherein the reaction vessel is supplied in a flow rate ratio of 10 to 40% with respect to a total flow rate of the chlorosilicon compound gas. 4. The solar cell production according to claim 1, wherein the pressure of the reaction vessel is set in the range of 0.5 to 10 Torr in the formation of at least an i-type microcrystalline silicon layer or a polycrystalline silicon layer. Method. The solar cell production according to claim 1 or 3, wherein the pressure of the reaction vessel is set in the range of 0.5 to 3 Torr in the film formation of at least i-type microcrystalline silicon layer or polycrystalline silicon layer. Method. A first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, a second transparent electrode, and a back electrode are sequentially formed on the transparent insulating substrate, and the transparent insulating substrate side In solar cells that make light incident from
  Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 1 chlorine. ¹⁸ cm ^-3 ~ 8x10 ²⁰ cm ^-3 A solar cell comprising: At least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 2 × 10 6 chlorine. ¹⁹ cm ^-3 ~ 4x10 ²⁰ cm ^-3 The solar cell according to claim 10, which is contained. Further, the pin having the same arrangement of p, i, n as the microcrystalline silicon layer or the polycrystalline silicon layer between the first transparent electrode and the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure. The solar cell according to claim 10, wherein an amorphous silicon layer having a structure or a nip structure is disposed. A back electrode, a first transparent electrode, a microcrystalline silicon layer or a polycrystalline silicon layer having a pin structure or a nip structure, and a second transparent electrode are sequentially formed on a transparent insulating substrate, and the second transparent electrode side In solar cells that make light incident from
  Of the microcrystalline silicon layer or the polycrystalline silicon layer having the pin structure or the nip structure, at least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 1 × 10 1 chlorine. ¹⁸ cm ^-3 ~ 8x10 ²⁰ cm ^-3 A solar cell comprising: At least the i-type microcrystalline silicon layer or the polycrystalline silicon layer contains 2 × 10 6 chlorine. ¹⁹ cm ^-3 ~ 4x10 ²⁰ cm ^-3 The solar cell according to claim 13, which is contained. Further, the pin having the same arrangement of p, i, n as the microcrystalline silicon layer or the polycrystalline silicon layer between the microcrystalline silicon layer or polycrystalline silicon layer having the pin structure or the nip structure and the second transparent electrode. The solar cell according to claim 13, wherein an amorphous silicon layer having a structure or a nip structure is disposed.

Images