JP5007293B2 - Method for producing chalcogen compound powder - Google Patents

Description

  The present invention relates to a method for producing a chalcogen compound powder containing a chalcogen-based element used for forming a light absorption layer of a thin-film solar cell, a phosphor, an electrode film for a Peltier element, and the like, and in particular, cheap and safe chalcogen compound powder. The present invention relates to a method for producing a chalcogen compound powder producing

  As nano-sized powders of metal compounds, for example, semiconductor nanocrystals, especially cadmium telluride (CdTe), cadmium selenide (CdSe), cadmium sulfide (CdS), copper indium gallium selenium (CuInGaSe), copper indium selenium (CuInSe) In addition to being able to control the light absorption spectrum and light emission by the size effect of the diameter, the band gap of the compound can be controlled by the formation of a solid solution. Is being actively conducted.

The synthesis of CdSe nanocrystals using dimethylcadmium (Cd (CH ₃ ) ₂ ) as a cadmium precursor as an example of a method for synthesizing CdSe nanocrystals that are nanoparticles of chalcogen compounds was first reported by Murray et al. Since 1), it has been developed. In the present application, the chalcogen compound refers to a compound having one or more metal elements and one or more elements selected from Se, S, and Te as constituent elements. Barbera-Guillem et al. Discloses a continuous flow method for the production of nanocrystals using the method of Murray et al. (See Patent Document 1).

This synthetic method requires the use of organometallic compounds such as dimethylcadmium as precursors that are very toxic, ignitable, expensive, and unstable at room temperature. At the standard injection temperature (340 to 360 ° C.) required for nanocrystal synthesis using Cd (CH ₃ ) ₂ as a precursor, ignitable Cd (CH ₃ ) ₂ is generated in large quantities. There are problems such as the cost of the countermeasures. For these reasons, synthetic methods involving Cd (CH ₃ ) ₂ are very limited in experimentation and conditions and are therefore not suitable for large scale synthesis. Similarly, when producing semiconductor nanocrystals containing other chalcogen elements, the use of alkyl metal compounds and metal alkoxides is also safe because of high vapor pressure, danger of explosion, and the toxicity of gases. There is a problem that the above measures are costly.

  Therefore, a metal oxide or metal salt is used as a precursor as an inexpensive and non-ignitable material, and the metal oxide or metal salt is mixed with a ligand and a coordination solvent to form a soluble metal complex. There is also known a method in which a chalcogen precursor (such as selenium (Se), tellurium (Te), or sulfur (S)) is added to form nanocrystals (see Patent Document 2). Ligands as cationic species of such metal complexes include long chain fatty amines or fatty acids, phosphonic acids, and phosphine oxides. Specific types included in these groups include dodecylamine (DA), hexadecylamine (HA), octadecylamine (OA), stearic acid (SA), lauric acid (LA), hexylphosphonic acid (HPA). , Tetradecylphosphonic acid (TDPA), and trioctylphosphine oxide (TOPO).

  At this time, if the melting point of the ligand is too high, the ligand remains solid at high temperature and does not function as a useful coordination solvent. In this case, such a ligand needs to be used in combination with another solvent. In order to form a metal complex having such a ligand, the metal oxide or salt is changed to a stable soluble metal complex by heating. Thus, a metal complex can be formed by mixing a precursor species with the ligand alone, and if a solvent is used, a soluble complex mixes the precursor species with the ligand / solvent molecule. Can be generated.

For example, when synthesizing a chalcogen compound powder in which the metal element is cadmium, a ligand such as phosphonic acid or carboxylic acid is added to cadmium oxide (CdO) or cadmium acetate (Cd (Ac) ₂ ). The cadmium complexes obtained are either cadmium phosphonate or cadmium carboxylate, respectively. Finally, a chalcogen element precursor (such as Se, Te, or S) is added to the dissolved cadmium complex to terminate the formation of nanocrystals (chalcogen compound powder) at a controllable rate. For example, when CdO is used as a cadmium source material, a chalcogen compound powder (nanocrystal) in which CdSe, CdTe, CdS, or other type of metal element is cadmium is synthesized by changing the precursor of the chalcogen element. It is possible.
US Pat. No. 6,179,912 Japanese translation of PCT publication No. 2004-510678 Journal of the American Chemical Society (1993), 115, 8706-8715.

However, in the synthesis method using such a ligand, it is necessary to change the ligand depending on the type of metal element to form a metal complex, and the chalcogen compound to be synthesized is copper gallium selenide (CuGaSe ₂ ) or In the case of a ternary system such as copper indium selenide (CuInSe ₂ ) or a quaternary system such as CuIn _1-x Ga _x Se ₂ , it is difficult to obtain a target chalcogen compound. In the case of a compound such as binary cuprous selenide (Cu ₂ Se), it may be difficult to select a ligand. Furthermore, there has been a problem in the treatment of wastewater containing ligands. For example, since hexylphosphonic acid (HPA), tetradecylphosphonic acid (TDPA), and trioctylphosphine oxide (TOPO) are toxic in any case, wastewater treatment for removing these compounds contained in wastewater is necessary. There was a problem of high wastewater treatment costs. Moreover, it is difficult to obtain a ternary or higher chalcogen compound.

  In the case of a production method using an organometallic compound such as dimethylcadmium as a precursor, the organometallic compound is expensive, and further has a problem of being toxic and ignitable and increasing the cost of safety measures. .

The present invention has been made in view of such problems, and a simple substance selected from a metal hydroxide or a metal compound powder of a metal oxide, sulfur, selenium, and tellurium as a reducing solvent having a boiling point of 200 ° C. or higher. Or a step of adding a compound containing one or more selected from the group of elements to form a mixed solvent, and a step of heating the mixed solvent at a temperature of 200 ° C. to 500 ° C. To do.

  The mixed solvent is heated at 220 ° C. to 400 ° C.

  In addition, the metal compound powder includes a compound selected from the group consisting of a transition metal element, a group III metal element, and a group VI metal element.

  Further, the transition metal element is Fe, Co, Cu, Cr, Mn, Ni, Cd, Zn, Ti, V, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb, It is characterized by including 1 or more types.

  Further, the group III metal element contains Al, Ga, Tl and In.

  Further, the group VI metal element contains Sn and Pb.

  Further, the reducing solvent is an alcohol solvent having a boiling point in the range of 220 ° C. to 400 ° C.

  The metal oxide is obtained by a dehydration reaction of a hydroxide that heats the metal hydroxide within a range of 70 ° C to 300 ° C.

  The metal compound powder is produced by dissolving a metal salt in a solvent and adding an alkali.

  Furthermore, the metal salt is selected from the group consisting of metal halides, metal carboxylates, metal carbonates, metal nitrates, and metal sulfates.

  According to the present invention, a nanoparticle powder (nanocrystal powder) of one or more kinds of metals and one or more kinds of compounds (chalcogen compounds) selected from sulfur, selenium, and tellurium is generated using an inexpensive metal salt as a raw material. be able to. Since no organic metal is used as a raw material and no metal complex is used as an intermediate, the production cost is low, and it is a safe method that does not discharge organic toxic substances in the wastewater. A method for producing a chalcogen compound powder that is nanoparticles having a particle diameter of 40 nm or less can be provided.

  Hereinafter, the present embodiment will be described in detail with reference to FIGS. FIG. 1 is a flowchart showing a method for producing a chalcogen compound powder of the present embodiment.

  The manufacturing method of the chalcogen compound powder of this embodiment mixes the metal compound powder which consists of 1 or more types of a metal hydroxide or a metal oxide, and a reducing solvent, sulfur (S), selenium (Se), tellurium ( And a step of adding a compound (one or more) selected from Te) to form a mixed solvent, and a step of heating the mixed solvent at a temperature of 200 ° C to 500 ° C. By this method, a chalcogen compound powder having an average particle size of 40 nm or less can be obtained.

  The metal compound powder used as a raw material can be a metal hydroxide or a metal oxide powder. The metal hydroxide can be produced by dissolving a metal salt in a solvent and adding an alkali. The metal oxide powder can be obtained by oxidizing (dehydrating) a metal hydroxide.

  Hereinafter, a case where a metal salt is used as a starting material will be described as an example, but a metal hydroxide or a metal compound powder of a metal oxide can also be used as a starting material.

  That is, in this embodiment, after dissolving a metal salt in a solvent and adding an alkali to precipitate a metal hydroxide, decantation, centrifugal sedimentation, filtration, etc. are performed, washed with water as necessary, and dried. To obtain a metal hydroxide. Alternatively, a metal hydroxide metal compound powder obtained by oxidizing (dehydrating) a metal hydroxide, or a hydroxide or oxide metal compound powder as a starting material is mixed in a reducing solvent, and the reducing solvent is used. It heats in the state which added the chalcogen source, and produces | generates a predetermined | prescribed chalcogen compound. By selecting the type of metal compound and chalcogen source to be used, various chalcogen compound powders can be obtained.

  The metal salt of this embodiment is selected from any group of metal halides, metal carboxylates, metal carbonates, metal nitrates, and metal sulfates.

Specifically, as a metal salt used as a starting material, for example, a metal halide salt includes cupric chloride (CuCl ₂ ), cadmium chloride (CdCl ₃ ), indium chloride (InCl ₃ ), copper bromide (CuBr ₂ ). ), Metal iodides such as copper iodide (CuI ₂ ), metal bromides, metal iodides, metal fluorides, and the like. As strong metal salts, copper sulfate (CuSO ₄ ), cupric nitrate ( Examples thereof include sulfates and nitrates such as Cu (NO ₃ ) ₂ ) and indium sulfate (In ₂ (SO ₄ ) ₃ ). In addition, copper acetate (Cu (CH ₃ COO) ₂ ), cupric formate (Cu (HCOO) ₂ ), copper oxalate (Cu (Cu (CH)) using carboxylic acids such as acetate, formate and oxalate There are metal salts such as COO) ₂ ). These salts may contain water of crystallization.

  The metal element contained in the metal salt includes at least one of 3d and 4f transition metal elements, group III metal elements, and group VI metal elements. 3d and 4f transition metal elements include iron (Fe), cobalt (Co), copper (Cu), chromium (Cr), manganese (Mn), nickel (Ni), cadmium (Cd), and zinc (Zn). , Titanium (Ti), vanadium (V), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy) , Erbium (Er), and ytterbium (Yb). Examples of Group III metal elements include aluminum (Al), gallium (Ga), thallium (Tl), and indium (In). In addition, examples of the Group VI metal element include tin (Sn) and lead (Pb).

These metal salts are dissolved in a polar solvent such as water or alcohol. Then, it neutralizes by adding an alkali and produces | generates a metal hydroxide. Specifically, it is precipitated as a metal hydroxide by an aqueous ammonia solution, sodium hydroxide, potassium hydroxide, or an alkaline organic compound having an amino group. At this time, in the case where the chalcogen compound to be obtained is a compound containing a plurality of metal elements, at least two of the metal salt components are obtained in order to obtain a metal hydroxide precipitate having the same metal element ratio as the chalcogen compound. Metal hydroxide is generated using metal salts of more than seeds. Specifically, for example, when producing CuInSe ₂ , metal hydroxide is used using a copper salt and an indium salt as raw materials so that the atomic ratio of copper (Cu) and indium (In) is 1: 1. Produce things. For this purpose, for example, nitrates such as Cu (NO ₃ ) ₂ and indium trinitrate (In (NO ₃ ) ₃ ) are produced as a hydroxide of Cu and In by a sodium hydroxide aqueous solution. It is also possible to produce copper hydroxide and indium hydroxide separately and use them.

The slurry containing these metal hydroxides is removed once with a centrifugal dehydrator, a high-speed centrifugal settling tube, or a filter press, Nutsche, etc., and then redispersed in a polar solvent such as water or ethanol. Further, the operation of removing the solvent is repeated to perform washing. It is desirable that the washing is repeated until the conductivity of the residual liquid (filtrate) becomes 10 ⁻¹ Sm or less. In particular, if alkali metal remains, it does not volatilize and therefore remains as an impurity element, which is a problem.

  Reaction impurities can be removed by washing. The end point of the pH in the neutralization in this embodiment is preferably alkaline. The pH is not particularly limited, but may be 10 or more, for example. Moreover, the lower the conductivity of the filtrate by washing with water, the better. However, when the pH approaches neutral, the metal hydroxide itself elutes and the composition changes, so the pH of the filtrate is maintained at 7.5 or higher. It is desirable to do.

  Thereafter, the metal hydroxide is dried, for example, at 70 to 90 ° C. to obtain a metal hydroxide powder (metal compound powder). At this time, the drying temperature is not particularly limited, and the drying temperature can be lowered by vacuum drying. The drying temperature may be 200 ° C. or higher.

  The metal hydroxide may be heated and oxidized to produce a metal oxide powder (metal compound powder).

Specifically, the moisture content of the slurry containing the metal hydroxide, in which the conductivity of the filtrate was reduced to 10 ⁻¹ Sm or less by washing, was adjusted to 50% or less, and this slurry (or cake) was used again as a solvent. Disperse.

  By introducing a gas such as air, nitrogen, or argon into a solvent containing a metal hydroxide to evaporate water (bubbling) to the outside, the solvent temperature is heated within a range of 70 ° C. to 300 ° C. The metal hydroxide inside becomes a metal oxide or a mixture of metal oxide and metal hydroxide, the aggregated metal hydroxide dissociates, and the size of primary particles in the solvent is 1 nm to 200 nm. It can be set as the state where powder exists in an unsintered state.

  At this time, the solvent molecules themselves may be dispersed in the solvent by wrapping the particles in the form of chemical bonds or physical adsorption. Alternatively, a surfactant may be added to the solvent to disperse the particles in the solvent. The particles dispersed in the solvent in this way are desirable because the particles can be prevented from agglomerating and sintering during surface treatment or other reaction treatment with the particles.

  Since the reaction during the oxidation releases water into the solvent, bubbling may be performed as described above, but the oxidation reaction may be promoted by raising the temperature in an autoclave.

  In this example, the metal oxide is produced after washing the metal hydroxide. However, after the metal hydroxide is produced and heated in the same solvent, the metal oxide is produced. A cleaning operation may be performed. Moreover, when performing a metal hydroxide production | generation and a chalcogenation reaction in the same solvent, you may perform washing | cleaning operation after a chalcogenation reaction. In any stage, the reaction impurities can be appropriately removed by washing.

  Next, a metal hydroxide or a metal compound powder of metal oxide and a reducing solvent are mixed, and a simple substance selected from S, Se, Te, or a compound containing one or more selected from the element group is added. To produce a mixed solvent, which is heated.

  Here, the reducing solvent is a metal hydroxide or a metal compound powder of metal oxide (hereinafter referred to as a metal compound powder), a simple substance selected from S, Se, and Te, or one kind selected from the element group. When the compound containing the above is coexisted in a solvent and heated, it refers to a solvent having the ability to deprive the metal compound of oxygen atoms and consequently generate a chalcogen compound. As the reducing solvent, those having a boiling point of 200 ° C. or higher are preferable, and those having a boiling point of 220 ° C. or higher are particularly preferable. As will be described later, in order to obtain a chalcogen compound, it is necessary to heat the reducing solvent to 200 ° C. or higher, preferably 220 ° C. or higher. If the boiling point of the reducing solvent is within the above temperature range, the chalcogen is generated under normal pressure. The reaction to obtain the compound can be performed. When the reaction is carried out under pressure, a solvent having a boiling point of less than 200 ° C. can also be used.

  An example of the reducing solvent is an alcohol solvent having a boiling point in the range of 100 ° C to 400 ° C. In order to perform the chalcogenation reaction at normal pressure, the boiling point is preferably 200 ° C. or higher, more preferably 220 ° C. or higher, and further preferably 250 ° C. or higher in consideration of the yield of the chalcogen compound.

Specifically, the reducing solvent includes a monohydric alcohol or a dihydric alcohol glycol. Examples of the monohydric alcohol include butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, decyl alcohol, nonyl alcohol, cyclopentanol, benzyl alcohol, and cinnamyl alcohol. Examples of glycol solvents include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, benzpinacol, hydro Benzoyl, cyclopentadiol, cyclohexanediol, cyclohexanediol, glycolic acid amide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monoethyl ether, diethylene glycol dibutyl ether, acetic acid diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, etc. big Intended polyethylene glycol, polyethylene glycol esters, polyethylene glycol ethers. In particular, glycols and diols are preferable because they have two hydroxyl groups and thus have polarity and contribute to the dispersibility of the powder. Examples of such a solvent include —CH ₂ —CHOH, or —CHR—CHOH, —CR ₁ R ₂ —CHOH, ═CHCHOH, ═CRCHOH (R, R ₁ , R ₂ : side chain) in the molecule. The boiling point of the solvent is at least 100 ° C. or higher. Furthermore, an organic compound having an aldehyde group —CHO has the same effect. For example, as an aliphatic saturated aldehyde, lauric aldehyde, tridecyl aldehyde, myristic aldehyde, capron aldehyde, heptaldehyde, pentadecyl aldehyde, palmitic aldehyde, marga aldehyde. Examples include aliphatic aldehydes such as succindialdehyde, aliphatic unsaturated aldehydes such as crotonaldehyde, and aromatic aldehydes such as benzaldehyde, tolualdehyde, salicylaldehyde, and cinnamaldehyde. And naphthaldehyde, and the heterocyclic aldehyde includes furfural. Examples of amine-based reducing solvents include hexylamine, hebutinamine, octylamine, undecylamine, tridecylamine, tetradecylamine, pentadecylamine, cetylamine, dibutylamine, diamylamine, cyclohexylamine, aniline, naphthylamine, and toluidine. is there.

  In addition, as a compound (hereinafter referred to as a chalcogen source) that is added to the reducing solvent together with the metal compound powder and is selected from S, Se, Te, or a compound containing one or more selected from the element group (hereinafter referred to as a chalcogen source) Alloy powders, hydrogenated chalcogen compounds, or organometals of chalcogen elements can be used.

  The alloy is an alloy having two or more elements selected from the group consisting of Se, Te, and S as constituent elements.

Representative examples of the hydrogenated chalcogen compound include hydrogen selenide (H ₂ Se), hydrogen sulfide (H ₂ S), hydrogen telluride (H ₂ Te), and the like. Are alkyl selenol, aryl selenol, dialkyl selenide, diaryl selenide, halogenated alkyl selenide, halogenated aryl selenide, dialkyl selenoxide, diaryl selenoxide, selenone, alkyl selenic acid, aryl selenic acid, selenonic acid , Selenoketone, selenoic acid, selenophene, and the like. For example, typical examples of dialkyl selenium include Se (CH ₃ ) ₂ , (C ₂ H ₅ ) ₂ Se, (C ₄ H ₉ ) ₂ Se, (C ₆ H ₁₃ ) ₂ Se, and the like. One or more of these chalcogen-based elements (Se, S, Te), simple substances, alloys and compounds can be used.

  And the mixed solvent of the said chalcogen source, a metal compound powder, and a reducing solvent is heated at the temperature of 200 to 500 degreeC. Thereby, the chalcogen source, the mixed solvent of the metal compound powder and the reducing solvent are subjected to a chalcogenization reaction, and the chalcogen compound powder can be easily obtained. If the heating temperature (temperature for the chalcogenation reaction: hereinafter, reaction temperature) is low, the formation of the chalcogen compound may not be sufficient, and even if it is 400 ° C. or higher, the production state of the obtained chalcogen compound is greatly changed. Is not seen, Preferably, it is 220 to 400 degreeC, More preferably, it is the range of 250 to 400 degreeC.

  In the present embodiment, a reducing solvent having a boiling point higher than that of ethyl alcohol or the like is heated to the above temperature range (200 ° C. to 500 ° C.), so that the solvent acts as a reducing agent to reduce the metal compound powder and chalcogen. It is considered that a chalcogen compound powder can be easily obtained by reacting Se, Te, S as a source and a reduced metal. Further, the particles of the chalcogen compound powder thus prepared have a particle diameter of 1 nm to 200 nm, and a powder having no sintering or bonding between particles is obtained. By adjusting the particle diameter of the metal compound powder, a chalcogen compound component having a particle diameter of 1 nm to 40 nm can be obtained.

  As will be apparent from the following examples, the higher the heating temperature of the mixed solvent, the better the result. However, when the mixed solvent (reducing solvent) is heated to a high temperature until boiling, the chalcogenation reaction proceeds, but the reducing solvent thermally decomposes or evaporates, so that the reaction becomes unstable. Therefore, the heating temperature (reaction temperature) of the mixed solvent is lower than the temperature at which the mixed solvent boils. Specifically, the heating temperature (reaction temperature) of the mixed solvent of this embodiment is preferably 220 ° C. or higher, and more preferably 250 ° C. or higher, from the viewpoint of the yield of the chalcogen compound. The upper limit temperature of the reaction temperature is preferably not higher than the boiling point of the solvent, specifically 500 ° C. or lower.

For example, according to this embodiment, an example of obtaining a CuInSe-based chalcogen compound is as follows. Cu and In metal hydroxides obtained by adding a sodium hydroxide aqueous solution to an aqueous solution containing Cu (NO ₃ ) ₂ and In (NO ₃ ) ₃ (after oxidation) are mixed with a reducing solvent, Metal Se powder is added to the solvent and heated to 220-400 ° C. Thereby, a reaction for generating a chalcogen compound (hereinafter, chalcogenation reaction) is remarkably accelerated, and a CuInSe-based compound is easily formed.

  In such a reaction, the same effect was obtained when the reaction was carried out using other chalcogen elements. More specifically, other CdSe series, CuInGaSe series, copper selenide (CuSe) series, tellurium selenide (TeSe) series, zinc selenide (ZnSe) series, gallium selenide (GaSe) series, indium selenide (InSe). ), Cobalt selenide (CoSe), samarium selenide (SmSe), manganese selenide (MnSe), tin selenide (SnSe), cerium selenide (CeSe), etc. The effect was obtained. Fe, Co, Cu, Cr, Mn, Ni, Cd, Zn, Ti, V, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb, Al, Ga, Tl, and InSn and In Pb, the same effect was obtained in the chalcogenation reaction. During the chalcogenation reaction, water is released due to the reaction, and the reaction easily proceeds by bubbling with nitrogen or argon as a reducing solvent, and tends to be a single phase of the compound containing the target chalcogen element. When the gas flow rate is large, there is a possibility that a chalcogen element having a high vapor pressure is carried out of the system of the chalcogenation reaction, and therefore there is an appropriate amount.

  The order of mixing and adding the metal compound powder, reducing solvent, and chalcogen source is not limited to the above example. That is, in the step of producing a metal hydroxide from a metal salt, a solution obtained by adding a reducing solvent to pure water may be used as a metal salt solution. Further, a high boiling point solvent may be used as a solvent in the step of generating (oxidizing) the metal oxide from the metal hydroxide. Furthermore, a high boiling point solvent may be used as a solvent in the step of generating (oxidizing) the metal oxide from the metal hydroxide, and a reducing solvent may be added when the chalcogen source is added.

Further, the chalcogen source to be added may not be powdery, and for example, a gas such as hydrogen selenide (H ₂ Se) may be supplied. As described above, when the metal compound powder and the reducing solvent are mixed and heated, bubbling with nitrogen or the like facilitates the reaction. Therefore, a gasified chalcogen source may be supplied together with the bubbling gas. .

  If a pressurizing apparatus is used for the chalcogenation reaction, a reducing solvent having a boiling point at normal pressure lower than 200 ° C. can be used.

  In the present embodiment, when the solid content concentration in the liquid of the metal compound at the start of the chalcogenization reaction is thin, it is easy to disperse and there is little aggregation, but the production amount per reaction is small, and conversely, the solid content concentration is high. Since binding and aggregation between chalcogen compound particles are likely to occur, the solid content concentration of the metal compound at the start of the chalcogenization reaction is preferably in the range of 0.1% by mass to 50% by mass. More preferably, it is the range of 0.1 mass%-10 mass%.

  In addition, the amount of chalcogen source added during the chalcogen reaction can be equal to or greater than the amount of the metal compound. When the chalcogenation reaction temperature is high, the chalcogen source may evaporate out of the reaction system before the chalcogenation reaction is completed, but by adding more than the equivalent amount, the loss due to the evaporation can be compensated. . Even when added in excess of the equivalent amount, the surplus chalcogen source is lost from the mixed solvent by evaporation after the chalcogen reaction, so the amount of chalcogen source added, the temperature of the chalcogenization reaction, the time, etc. may be adjusted as appropriate. Since it is uneconomical to add the chalcogen source excessively, it is preferable to add 1 to 1.3 times the equivalent amount.

  In the present application, hereinafter, when it is described as excessively added, it means that an amount of more than 1 time and not more than 1.3 times the equivalent is added.

  The thus produced chalcogen compound powder can be dispersed in a target solvent by a solvent substitution method. At this time, a surfactant can be attached to the particle surface so that the solvent can be easily replaced, and the surfactant can be easily dispersed in the target solvent.

Specifically, the surfactant is not limited to the type of anionic, cationic, nonionic, etc., by controlling the pH in the solvent to charge the particle surface to the positive or negative side, By selecting a surfactant having a charge on the opposite side to the polarity of the charged state, the surfactant can be adsorbed appropriately. Specifically, when the pH is controlled to be on the acidic side, the particle surface tends to be positively charged, and in this case, organic molecules having a functional group such as COO- and SO3- are easily adsorbed. . There are those having functional groups such as sulfone groups and sulfino groups that are easily dissociated in a solvent and easily become anions, but those such as R ₁ R ₂ SO ₂ that do not dissociate and are involved in the polarity of the molecule But it is effective for dispersion. Conversely, when the pH of the solvent is changed to the alkaline side, those having amino groups such as —NH ₂ and —NRH are easily adsorbed, and the surfactant should be selected according to the charged state of the particle surface. Is desirable. In some cases, if -OH is present on the surface of the particle, it may be chemically bonded by ester bonding with the carboxyl group of the surfactant. Alternatively, a coupling agent such as Si, Al, or Ti can be used when the impurity concentration does not matter.

  Hereinafter, the embodiment will be described in detail with reference to FIGS.

  In Example 1, a metal compound powder of a metal oxide was produced from a metal salt via a metal hydroxide, mixed with a reducing solvent, added with a chalcogen source, and heated. In Example 1, triethyleneglycol (TEG) is used as a high boiling point solvent in the step of generating (oxidizing) a metal oxide from a metal hydroxide, and a reducing solvent is added when a chalcogen source is added. Added.

That is, in order to synthesize Cu ₂ Se particles, 150 ml of a solution obtained by dissolving 0.05 mol of copper nitrate as a metal salt in pure water was placed in a 250 ml flask. Subsequently, in a state where the inside of the flask was rotated and stirred with a blade having a diameter of 5 cm at 300 rpm, a 10N solution of sodium hydroxide was added dropwise to neutralize, and the pH was terminated at 8.5 to produce copper hydroxide. Then, after filtering using Nutsche, the cake was re-dispersed with pure water, and the filtration was further repeated, so that the conductivity of the filtrate was 10 ⁻¹ Sm ⁻¹ or less. At this time, when the pH of the liquid in which the copper hydroxide was dispersed approached 7, the copper hydroxide was dissolved, so the pH was kept at about 7.5. The metal hydroxide cake was then dried at 70 ° C. As a result of observing the form of copper hydroxide after washing with a transmission electron microscope (hereinafter referred to as TEM), it was a form in which very fine particles were aggregated.

  5 g of the dried copper hydroxide was put into a 250 ml three-necked flask, added to 75 g of triethylene glycol (TEG) as a high boiling point solvent, and stirred by rotating a feather with a diameter of 5 cm at 300 rpm. Bubbling with min. In this state, each was heated for 3 hours at 10 different temperatures (oxidation heating temperatures) from 80 ° C. to 300 ° C. shown in FIG. 2 to obtain a copper compound.

FIG. 2 confirms the particle size (average particle size: D ₅₀ , the same applies hereinafter) of the copper compounds (sample 1 to sample 10) prepared at each of the 10 heating temperatures (oxidation heating temperatures) and the state of compound formation. The results are shown. Here, the particle size was measured using a particle size distribution measuring device by laser scattering, and the state was confirmed with respect to the approximate ratio of copper hydroxide / copper oxide from the peak position and height of X-ray diffraction. As a result, it was found that when the oxidation heating temperature is 120 ° C. or higher, particles having a particle size of 3 μm or less and mainly copper oxide can be obtained. Since a particle size distribution measuring device using laser scattering is used for the particle size, primary particles and secondary particles in which primary particles are aggregated are simultaneously measured.

In FIG. 2, the case where the average particle diameter (D ₅₀ ) measured using a particle size distribution measuring device by laser scattering is 2 μm or less is evaluated as ◯, the case where it exceeds 2 μm and 3 μm or less, and the case where it exceeds 3 μm is evaluated as ×. .

  From FIG. 2, it can be seen that the higher the oxidation heating temperature, the smaller the average particle size, and the dispersion proceeds. As a result of confirming the primary particle size of the copper compound by TEM observation, when the oxidation heating temperature is 150 ° C. or higher, the primary particle size is about 30 nm, and the primary particles are very fine, and are aggregated. Had become. Conversely, when the oxidation heating temperature is as low as 110 ° C. or lower, the copper oxide ratio is low and the secondary particle size is large. From this result, in order to obtain metal compound particles mainly composed of metal oxide having a small secondary particle size, it is preferable that the oxidation heating temperature is high. When the metal is copper, the oxidation heating temperature is preferably 120 ° C. or higher.

Next, the mixed solvent containing particles treated at an oxidation heating temperature of 200 ° C. was subjected to solid-liquid separation by centrifugal sedimentation. Using a centrifuge (domestic centrifuge Co., Ltd. H-103N), it was subjected to solid-liquid separation by centrifugation at 3000 rpm for 30 minutes, and 3 g of solid content (metal compound powder) was taken out. Se powder was added as a source. As the chalcogen source, Se powder was excessively added so that the atomic ratio of Cu to Se (Cu: Se) was 2: 1.2. Then, in addition to 50 g of TEG (reducing solvent), a mixed solvent was obtained. The flask was put into a 250 ml three-necked flask, and a feather having a diameter of 5 cm was rotated and stirred at 300 rpm, and nitrogen was bubbled at 100 ml / min. In this state, each of the 10 kinds of temperatures (reaction temperatures) shown in FIG. 3 at 150 ° C. to 300 ° C. was heated for 5 hours, reacted (chalcogenization reaction), and chalcogen compound powder was produced. Washing and drying were repeated by washing and filtering with isopropyl alcohol to reduce the electrical conductivity of the filtrate to 10 ⁻¹ Sm ⁻¹ or less and vacuum drying at 60 ° C.

The result is shown in FIG. In FIG. 3, the crystal analysis by an X-ray analyzer (X-Ray Diffractometer, hereinafter referred to as XRD, RAD-rX manufactured by Rigaku Co., Ltd.) is mainly performed, and the generation state of the chalcogen compound (Cu ₂ Se) is examined for samples 1 to 10. The reaction temperature of the chalcogenation reaction necessary for the production of the chalcogen compound was examined. At this time, X-ray diffraction was measured under the condition of 50 kV and 100 mA, and the highest peak height among the peak intensities of the target chalcogen compound was divided by the highest peak height among the peak intensities of other substances. The value (hereinafter, peak intensity ratio) was determined. If the peak intensity ratio was 15 or more, it was determined that the target chalcogen compound was obtained with high purity (a single phase of the target product was obtained), and indicated by ○ in FIG. If the peak intensity ratio was 5 or more, it was determined that a substance having a high content of the target chalcogen compound was obtained, and the result is shown by Δ in FIG. When the peak intensity ratio was less than 5, the content of the target chalcogen compound was determined to be low, and indicated by x. The evaluation criteria are the same in other examples. As a result, it was found that a reaction temperature of at least 220 ° C. or higher is required for the chalcogenation reaction in order to produce a highly pure chalcogen compound.

  4 is a graph showing the X-ray diffraction result of the obtained chalcogen compound. FIG. 4 (A) shows the result of Sample 8, and FIG. 4 (B) shows the result of Sample 4. The vertical axis is the peak intensity [cps], and the horizontal axis is the diffraction angle (2θ) [°].

  Referring to FIG. 4A, in sample 8, no peak other than the peak indicating CuSe was observed. On the other hand, as shown in FIG. 4B, in Sample 4, the CuSe peak observed in Sample 8 (FIG. 4A) was hardly recognized.

Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 7 nm to 12 nm. D _TEM is TEM images, JEOL Ltd. JEM-2010, at shot by 100,000 times, of the total particle, measuring particle diameters of 100 particles and is the average.

  Some of the obtained chalcogen compounds were subjected to composition analysis by fluorescent X-rays. X-ray fluorescence analysis was performed using JSX-3201 manufactured by JEOL Ltd. as an apparatus.

FIG. 5 shows the analysis results, and the analysis results of Samples 8, 9, and 10 are shown in terms of atomic ratios of the constituent elements. According to this, it was confirmed that a chalcogen compound close to the target composition ratio (Cu: Se = 1: 1) was obtained.
(Comparative example)
As a comparison with Example 1, lauric acid having no reducing property was added instead of TEG. That is,
The synthesis of the chalcogen compound was attempted in the same manner as in Example 1 except that the solvent used for the chalcogenation reaction was changed from TEG to lauric acid and the heating time during the chalcogenation reaction was changed to 10 hours. However, the oxidation heating temperature was 200 ° C., and the chalcogenation reaction temperature was 220 ° C.

In FIG. 6, the result of having performed the evaluation similar to Example 1 is shown. When the reducing solvent was changed from TEG to lauric acid, Cu ₂ Se could not be generated sufficiently.

In Example 1, Cu ₂ Se particles were synthesized. In Example 2, CuInSe ₂ was synthesized using copper nitrate and indium nitrate as metal salts.

150 ml of a solution obtained by dissolving 0.01 mol of copper nitrate and 0.01 mol of indium nitrate in pure water so that the atomic ratio of Cu to In (Cu: In) was 1: 1 was placed in a 250 ml flask. Subsequently, while rotating a wing having a diameter of 5 cm at 300 rpm and stirring the flask, a 10N solution of sodium hydroxide was added dropwise to neutralize the solution, and the pH was terminated at 8.5. Was generated. Then, after filtering using Nutsche, the cake was re-dispersed with pure water, and filtration was further repeated, so that the filtrate had a conductivity of 10 ⁻¹ Sm ⁻¹ or less. At this time, when the pH of the liquid in which the metal hydroxide was dispersed approached 7, since the copper hydroxide was dissolved, the pH was kept at about 7.5. The metal hydroxide cake was then dried at 70 ° C. 2 g of the dried product was put into a 250 ml three-necked flask, and further added to 75 g of triethylene glycol (TEG) as a reducing solvent, and a wing having a diameter of 5 cm was rotated and stirred at 300 rpm, and air was bubbled at 100 ml / min. . In this state, each of the 10 temperatures (oxidation heating temperatures) shown in FIG. 7 from 80 ° C. to 300 ° C. was heated for 1 hour to produce a metal compound powder, and the same evaluation as in Example 1 was performed.

  FIG. 7 shows the results of confirming the particle sizes and the compound formation states of Sample 1 to Sample 10 prepared at 10 different oxidation heating temperatures. The method for measuring the particle size and the method for checking the state are the same as in Example 1.

  It can be seen that the higher the oxidation heating temperature, the smaller the average particle size, and the more the dispersion proceeds. As a result of confirming the primary particle size of the metal compound by TEM observation, when the oxidation heating temperature is 150 ° C. or higher, the primary particle size is about 20 nm, and the primary particles are very fine and are aggregated. It has become. Conversely, when the oxidation heating temperature is as low as 110 ° C. or lower, the ratio of the metal oxide is low and the secondary particle size is large. From this result, in order to obtain metal compound particles mainly composed of metal oxide having a small secondary particle size, it is preferable that the oxidation heating temperature is high. When the metal is copper and indium, the oxidation heating temperature is 120 ° C. or more. preferable.

Next, the mixed solvent containing particles treated at an oxidation heating temperature of 250 ° C. was subjected to solid-liquid separation by centrifugal sedimentation. Using a centrifuge (domestic centrifuge Co., Ltd. H-103N), it was solid-liquid separated by centrifugation at 3000 rpm for 30 minutes, and 2 g of solid content (metal compound powder) was taken out. Se powder (chalcogen source) was added excessively so that the atomic ratio of Cu to Se (Cu: Se) was 1: 2.2 and added to 100 g of TEG to obtain a mixed solvent. The flask was put into a 250 ml three-necked flask, and a feather having a diameter of 5 cm was rotated and stirred at 300 rpm, and nitrogen was bubbled at 100 ml / min. In this state, each of the 10 reaction temperatures shown in FIG. 8 at 150 ° C. to 300 ° C. was heated for 5 hours to cause reaction (chalcogenization reaction) to generate chalcogen compound powder (CuInSe ₂ ). Similar evaluations were made. Washing and drying were repeated by washing and filtering with ethyl alcohol to reduce the electrical conductivity of the filtrate to 10 ⁻¹ Sm ⁻¹ or less and dried at 80 ° C. in the air.

FIG. 8 is a method similar to that of Example 1, for each sample produced at the 10 reaction temperatures shown in FIG. 8, the production state of the chalcogen compound was examined using an X-ray analyzer, and the reaction temperature of the chalcogenization reaction was determined. The results of the investigation are shown. From the evaluation result of X-ray diffraction, it was confirmed that CuInSe ₂ was obtained. It has been found that a reaction temperature of at least 220 ° C. or higher is required during the chalcogenation reaction in order to produce a highly pure chalcogen compound.

Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 7 nm to 12 nm.

FIG. 9 is a graph showing an X-ray analysis result of the obtained chalcogen compound (sample 8), in which the vertical axis represents peak intensity [cps] and the horizontal axis represents diffraction angle (2θ) [°]. From this result, in sample 8, no peak other than the peak indicating CuInSe ₂ was observed.

  Furthermore, composition analysis by fluorescent X-rays was performed for some of the obtained chalcogen compounds.

  FIG. 10 shows the analysis results, and the analysis results of Samples 8, 9, and 10 are shown in terms of atomic ratios of the constituent elements. According to this, it was confirmed that the chalcogen compound close | similar to the target composition ratio (Cu: In: Se = 1: 1: 2) was obtained.

In Example 2, as a reducing solvent in place of TEG, ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, benzpinacol, hydro As a result of examining the state of the product using benzoyl, cyclopentadiol, cyclohexanediol, cyclohexanediol, glycolic acid amide, diethylene glycol dimethyl ether, naphthylamine, dodecylamine and the chalcogenation reaction temperature as the respective solvent temperature, Similarly _{D TEM} and sample 8 of example 2 is chalcogen compound was obtained is 7Nm～12nm.

In Example 3, CuInSe ₂ was synthesized in the same manner as in Example 2 except that the step of oxidizing the metal hydroxide by heating was not performed.

  150 ml of a solution obtained by dissolving 0.01 mol of copper nitrate and 0.01 mol of indium nitrate in pure water so that the atomic ratio of Cu to In (Cu: In) was 1: 1 was placed in a 250 ml flask. Subsequently, while rotating a wing having a diameter of 5 cm at 300 rpm and stirring the flask, a 10N solution of sodium hydroxide was added dropwise to neutralize the solution, and the pH was terminated at 8.5. Was generated.

Then, after filtering using Nutsche, the cake was re-dispersed with pure water, and filtration was further repeated, so that the filtrate had a conductivity of 10 ⁻¹ Sm ⁻¹ or less. At this time, when the pH of the liquid in which the metal hydroxide was dispersed approached 7, since the copper hydroxide was dissolved, the pH was kept at about 7.5. Thereafter, the entire amount of the metal hydroxide cake is put into a 250 ml three-necked flask, and in addition to 100 g of triethylene glycol (TEG) which is a reducing solvent, the atomic ratio of Cu to Se (Cu: Se) is 1. : Se powder (chalcogen source) was added excessively to obtain a mixed solvent so as to be 2.2, and a wing having a diameter of 5 cm was rotated and stirred at 300 rpm, and nitrogen was bubbled at 200 ml / min. In this state, the mixed solvent was used under the conditions of the chalcogenation reaction in which the temperature was increased from 150 ° C. to 300 ° C. at 10 ° C./min. Samples 1 to 10 were produced by heating at different temperatures. Samples 1 to 10 prepared at each reaction temperature were evaluated in the same manner as in Example 1.

FIG. 11 shows this result. From the evaluation result of X-ray diffraction, it was confirmed that CuInSe ₂ was obtained. It has been found that in order to produce a highly pure chalcogen compound (CuInSe ₂ ), a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder produced in Samples 8, 9, and 10 by TEM, the average particle size (D _TEM ) was 6 nm to 12 nm.

FIG. 12 is a graph showing the X-ray analysis result of the chalcogen compound (sample 8) by the same method as in Example 1. FIG. 13 shows the fluorescent X-ray analysis result by the same method as in Example 1. From these, no peak other than the peak indicating that it is CuInSe ₂ was observed in sample 8 (FIG. 12), and the target composition ratio (Cu: In: Se = 1: 1) was obtained for samples 8, 9, and 10. : It was confirmed that a chalcogen compound close to 2) was obtained (FIG. 13).

  In addition, it turns out that the peak in the range of 20 degrees-25 degrees recognized in FIG. 12 originates in the adhesive material of a measurement jig | tool.

In Example 4, a reducing solvent was used as a solvent for producing a metal hydroxide from a metal compound powder. That is, a mixture of 0.01 mol of copper chloride and 0.01 mol of indium chloride in 30 ml of pure water and 100 g of TEG (reducing solvent) so that the atomic ratio of Cu to In (Cu: In) is 1: 1. Dissolved in solution and placed in a 250 ml flask. Subsequently, in a state where the wing having a diameter of 5 cm is rotated and stirred in the flask at 300 rpm, a potassium hydroxide aqueous solution having a concentration of 20 percent is dropped and neutralized to finish the pH at 8.5, and the metal hydroxide is coprecipitated. Product was produced. Thereafter, Se powder (chalcogen source) was added excessively so that the atomic ratio of Cu to Se (Cu: Se) was 1: 2.2 to obtain a mixed solvent, and nitrogen was bubbled at 200 ml / min. In this state, the temperature was raised to 120 ° C. and held for 2 hours, and then the temperature was raised to 10 types of temperatures shown in FIG. 14 from 150 to 300 ° C. at a rate of temperature rise of 1 ° C./min. A heated sample was produced by changing the temperature of the mixed solvent under the conditions of the retained chalcogenation reaction. Washing and drying were repeated by washing and filtering with methyl alcohol to reduce the conductivity of the filtrate to 10 ⁻¹ Sm ⁻¹ or less and drying at 60 ° C. in nitrogen. Samples 1 to 10 prepared at each reaction temperature were evaluated in the same manner as in Example 1.

FIG. 14 shows this result. From the evaluation result of X-ray diffraction, it was confirmed that CuInSe ₂ was obtained. It has been found that in order to produce a highly pure chalcogen compound (CuInSe ₂ ), a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 7 nm to 12 nm.

FIG. 15 is a graph showing the X-ray analysis results of the chalcogen compound (sample 8) by the same method as in Example 1, and FIG. 16 shows the fluorescent X-ray analysis results by the same method as in Example 1. From these, no peak other than the peak indicating that it is CuInSe ₂ was observed in sample 8 (FIG. 15), and the intended composition ratio (Cu: In: Se = 1: 1) was obtained for samples 8, 9, and 10. : It was confirmed that a chalcogen compound close to 2) was obtained (FIG. 16).

  In addition, it turns out that the peak which exists in the range of 20 degrees-25 degrees recognized in FIG. 15 originates in the adhesive material of a measurement jig | tool.

  In Example 5, a reducing solvent was used in the production of the metal hydroxide, and the gasified chalcogen source was supplied together with the bubbling gas of the reducing solution. That is, a mixture of 0.01 mol of copper chloride and 0.01 mol of indium chloride in 30 ml of pure water and 100 g of TEG (reducing solvent) so that the atomic ratio of Cu to In (Cu: In) is 1: 1. Dissolved in solution and placed in a 250 ml flask. Subsequently, in a state where the inside of the flask was rotated and stirred with a blade having a diameter of 5 cm at 300 rpm, ammonia water having a concentration of 20 percent was added dropwise to neutralize the solution, and the addition was terminated at pH 8.5. A precipitate was formed. Thereafter, a mixed gas having a volume ratio of 1: 1 between hydrogenated Se gas (chalcogen source) and nitrogen was added by bubbling the mixed solvent at 200 ml / min. In this bubbled state, the temperature was raised to 120 ° C. and held for 2 hours, and then the temperature was raised from 140 to 300 ° C. at 10 ° C./min. A sample heated by changing the temperature of the mixed solvent under the conditions of the chalcogenation reaction held at a temperature for 10 hours was prepared. Washing and drying after the chalcogenation reaction were carried out in the same manner as in Example 1. Samples 1 to 11 prepared at each reaction temperature were evaluated in the same manner as in Example 1.

FIG. 17 shows this result. From the evaluation result of X-ray diffraction, it was confirmed that CuInSe ₂ was obtained. It has been found that in order to produce a highly pure chalcogen compound (CuInSe ₂ ), a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder produced in Samples 9, 10, and 11 by TEM, the average particle size (D _TEM ) was 8 nm to 14 nm.

  FIG. 18 shows the result of fluorescent X-ray analysis by the same method as in Example 1. From these, it was confirmed that for samples 9, 10, and 11, chalcogen compounds close to the target composition ratio (Cu: In: Se = 1: 1: 2) were obtained.

  In order to produce CdSe in the same manner as in Example 5, 0.01 mol of cadmium chloride was dissolved in a mixed solution of 30 ml of pure water and 100 g of TEG (reducing solvent), and this solution was placed in a 250 ml flask. . Subsequently, while stirring and rotating a feather having a diameter of 5 cm at 300 rpm, the sodium hydroxide aqueous solution with a concentration of 20 percent was dropped to neutralize, and the dropping was terminated at a pH of 8.5. Was generated. Thereafter, a mixed gas having a volume ratio of 1: 1 between hydrogenated Se gas (chalcogen source) and nitrogen was added by bubbling the mixed solvent at 200 ml / min. In this bubbled state, the temperature was raised to 120 ° C. and held for 2 hours, and then the temperature was raised to 13 kinds of temperatures shown in FIG. 19 from 80 ° C. to 260 ° C. at a rate of 1 ° C./min. A sample heated by changing the reaction temperature of the mixed solvent under the conditions of the chalcogenation reaction held at a temperature for 10 hours was prepared.

  Samples 1 to 13 were subjected to solid-liquid separation by centrifugal sedimentation. Using a centrifuge (H-103N, manufactured by Kokusan Centrifuge Co., Ltd.), solid-liquid separation is performed by centrifugation at 3000 rpm for 30 minutes, and the solid content is dispersed in pure water repeatedly 5 times. The solid content thus obtained was evaluated in the same manner as in Example 1.

FIG. 19 shows this result. From the X-ray diffraction evaluation results, it was confirmed that CdSe was obtained. In order to produce a sufficient amount of chalcogen compound (CdSe), it has been found that a reaction temperature of at least 200 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 11, Sample 12, and Sample 13 with TEM, the average particle size (D _TEM ) was 6 nm to 10 nm.

  In the above neutralization reaction, sodium hydroxide was replaced with an aqueous ammonia solution and the other conditions were the same. The result was the same as the result of FIG. Result of washing chalcogen compound from centrifugal sedimentation method and pure water washing, after carrying out filtration with Nutsche, dispersing the solid content in pure water five times, and filtering under the same conditions except for filtration again The results are the same as those in FIG.

  FIG. 20 shows the result of fluorescent X-ray analysis of Samples 11, 12, and 13 by the same method as in Example 1. Thereby, it was confirmed that the chalcogen compound close | similar to the target composition ratio (Cd: Se = 1: 1) was obtained about sample 11,12,13.

  In Example 6, instead of cadmium chloride, each of Fe, Co, Cu, Cr, Mn, Ni, Zn, Ti, V, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, and Yb As a result of investigating whether a similar chalcogen compound powder can be produced when a neutralization reaction with sodium hydroxide is performed using chloride and the other conditions are the same, the heating temperature of the mixed solvent (chalcogen) for each element The reaction temperature of the chemical reaction was 220 ° C. or higher, and a chalcogen compound powder was obtained.

Moreover, FIG. 21 shows the result of performing the same test as in Example 1 by performing a similar test using (C ₂ H ₅ ) ₂ Se instead of hydrogen selenide in Example 6. As a result, CdSe of _{D TEM} by the heating temperature during chalcogen reaction above 220 ° C. could be produced particles is 15Nm～20nm.

In Example 7, a propylene glycol solvent in producing metal oxides from metal hydroxide: using (Propyleneglycol _PEG), was synthesized CuIn _{0.7 Ga} 0.3 Se _2. Purely 0.01 mol of copper nitrate, 0.007 mol of indium nitrate, and 0.003 mol of gallium nitrate so that the composition of Cu, In, and Ga is 1: 0.7: 0.3 by atomic ratio (Cu: In: Ga). A solution dissolved in 200 ml of water was placed in a 250 ml flask. Subsequently, in a state where the wings having a diameter of 5 cm were rotated and stirred in the flask at 300 rpm, a 1N solution of sodium hydroxide was added dropwise to neutralize, and the addition was terminated at pH 8.5 to co-precipitate the metal hydroxide. Product was produced. Then, after filtering using Nutsche to obtain a cake, the cake was redispersed with pure water, and the filtration was further repeated, so that the electrical conductivity of the filtrate was 10 ⁻² Sm ⁻¹ or less. At this time, since the copper hydroxide was dissolved when the pH approached 7, the pH was kept at about 7.5. The metal hydroxide cake was then vacuum dried at 90 ° C. 5 g of the dried metal hydroxide was put into a 250 ml three-necked flask, and further added to 75 g of propylene glycol (PEG) as a reducing solvent, and a feather having a diameter of 5 cm was rotated at 300 rpm and stirred. Thereafter, nitrogen was bubbled at 100 ml / min. In this state, 10 types of oxidation heating temperatures shown in FIG. 22 from 80 ° C. to 300 ° C. were used to prepare samples of metal compounds by heating at different temperatures for 1 hour. Washing and drying were performed by washing and filtering with isopropyl alcohol. Repeatedly, the electrical conductivity of the filtrate was reduced to 10 ⁻¹ Sm ⁻¹ or less and dried in nitrogen at 80 ° C. Evaluation was performed in the same manner as in Example 1.

FIG. 22 shows the evaluation results of Sample 1 to Sample 10 prepared at each oxidation heating temperature. It can be seen that the higher the oxidation heating temperature, the smaller the average particle size, and the more the dispersion proceeds. As a result of confirming the primary particle size of the metal compound by TEM observation, when the oxidation heating temperature is 150 ° C. or higher, the primary particle size is about 10 nm, and the primary particles are very fine, and are aggregated. It has become. Conversely, when the oxidation heating temperature is as low as 110 ° C. or lower, the ratio of the metal oxide is low and the secondary particle size is large. From this result, in order to obtain metal compound particles mainly composed of a metal oxide having a small secondary particle size, it is preferable that the oxidation heating temperature is high. When the metal is copper, gallium and indium, the oxidation heating temperature is 120 ° C. The above is preferable. Next, with respect to the solvent containing the metal compound processed at the oxidation heating temperature of 250 ° C., Se powder ( (Chalcogen source) was added in excess to obtain a mixed solvent. Subsequently, the solvent in the 250 ml three-necked flask was stirred by rotating a feather having a diameter of 5 cm at 300 rpm, and nitrogen was bubbled at 100 ml / min. In this state, the mixed solvent was heated at 11 reaction temperatures shown in FIG. 23 between 150 ° C. and 340 ° C. for 10 hours to try to produce a chalcogen compound. Washing and drying were repeated by washing and filtering with ethyl alcohol to make the filtrate have a conductivity of 10 ⁻¹ Sm ⁻¹ or less and dried at room temperature in the air. The obtained chalcogen compounds of Sample 1 to Sample 10 were evaluated in the same manner as in Example 1.

FIG. 23 shows this result. From the evaluation result of X-ray diffraction, it was confirmed that CuIn _0.7 Ga _0.3 Se ₂ was obtained. In order to produce a sufficient amount of chalcogen compound (CuIn _0.7 Ga _0.3 Se ₂ ), it has been found that a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 10 nm to 15 nm.

FIG. 24 is a graph showing the X-ray analysis result of the chalcogen compound (sample 8) by the same method as in Example 1. FIG. 25 shows the fluorescent X-ray analysis result by the same method as in Example 1. From these, in sample 8, no peak other than the peak indicating CuIn _0.7 Ga _0.3 Se ₂ was observed (FIG. 24), and the target composition ratio (Cu : In: Ga: Se = 1: 0.7: 0.3: 2) was confirmed to be obtained (FIG. 25).

  In addition, it turns out that the peak in the range of 20 degrees-25 degrees recognized in FIG. 24 originates in the adhesive material of a measuring jig.

  In Example 8, the test was performed in the same manner as in Example 7 except that the amount of Se powder (chalcogen source) to be added was 1: 2 in terms of the atomic ratio of Cu to Se (Cu: Se). Evaluation was performed in the same manner as in 1.

  FIG. 26 shows the evaluation results of Sample 1 to Sample 10 prepared at each oxidation heating temperature. The same results as in Example 7 were obtained.

FIG. 27 shows the evaluation results of the products obtained by the chalcogenation reaction by the same X-ray diffraction evaluation method as in Example 1 for Sample 1 to Sample 10. From the evaluation result of X-ray diffraction, it was confirmed that CuIn _0.7 Ga _0.3 Se ₂ was obtained. In order to produce a sufficient amount of chalcogen compound (CuIn _0.7 Ga _0.3 Se ₂ ), it has been found that a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 7 nm to 12 nm.

  FIG. 28 shows the result of fluorescent X-ray analysis by the same method as in Example 1. From these, it was confirmed that the chalcogen compounds close to the target composition ratio (Cu: In: Ga: Se = 1: 0.7: 0.3: 2) were obtained for samples 8, 9, and 10. It was done.

In the synthesis of CuIn _0.7 Ga _0.3 Se _{2 in} Example 8, instead of Se powder as the chalcogen source, the amount of SeS (added SeS powder (chalcogen source) to Cu is atomic ratio to Cu: Se: S And 1: 1: 1). Other conditions were the same.

FIG. 29 shows the evaluation results of the products obtained by the chalcogenation reaction by the same X-ray diffraction evaluation method as in Example 1 for Sample 1 to Sample 10. From the evaluation result of X-ray diffraction, it was confirmed that CuIn _0.7 Ga _0.3 SeS was obtained. It was found that a reaction temperature of at least 220 ° C. or higher was required during the chalcogenation reaction in order to produce a sufficient amount of the chalcogen compound (CuIn _0.7 Ga _0.3 SeS). Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 12 nm to 20 nm.

  FIG. 30 shows the results of fluorescent X-ray analysis of Samples 9, 10, and 11 by the same method as in Example 1. From these, the chalcogen compounds close to the target composition ratio (Cu: In: Ga: S: Se = 1: 0.7: 0.3: 1: 1) were obtained for Samples 9, 10, and 11. That was confirmed.

In Example 10, CuIn _0.7 Ga _0.3 Se ₂ was synthesized using a reducing solvent when producing a metal hydroxide from a metal salt. Purely 0.01 mol of copper chloride, 0.007 mol of indium chloride and 0.003 mol of gallium chloride so that the atomic ratio of Cu, In, and Ga (Cu: In: Ga) is 1: 0.7: 0.3. 50 ml of water and 100 g of TEG (reducing solvent) were dissolved in a mixed solution, and the solution was put into a 250 ml flask. Subsequently, while stirring and rotating a feather having a diameter of 5 cm at 300 rpm, a 1N solution of sodium hydroxide was added dropwise to neutralize, and the addition was terminated at a pH of 8.5. A precipitate was formed. Next, while rotating and stirring the wings having a diameter of 5 cm at 300 rpm, nitrogen was bubbled at 100 ml / min, and Se powder (chalcogen source) so that the atomic ratio of Cu to Se (Cu: Se) was 1: 2.5. ) Was added in excess to obtain a mixed solvent. In this state, the mixed solvent was heated at 10 reaction temperatures shown in FIG. 31 at 150 to 300 ° C. for 10 hours to try to produce a chalcogen compound. After this, the mixed solvent containing reactive organisms is filtered using a Nutsche, and then the cake is redispersed with pure water, and the filtration is further repeated so that the filtrate has a conductivity of 10 ⁻¹ Sm ⁻¹ or less. The cake obtained was vacuum-dried to obtain chalcogen compound powder (sample 1 to sample 10). This powder was evaluated in the same manner as in Example 1.

FIG. 31 shows the evaluation results obtained by evaluating the samples 1 to 10 (products obtained by the chalcogenation reaction) obtained above by the same X-ray diffraction as in Example 1. From the evaluation result of X-ray diffraction, it was confirmed that CuIn _0.7 Ga _0.3 Se ₂ was obtained. In order to produce a sufficient amount of chalcogen compound (CuIn _0.7 Ga _0.3 Se ₂ ), it has been found that a reaction temperature of at least 220 ° C. is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Samples 8, 9, and 10 by TEM, the average particle size (D _TEM ) was 7 nm to 13 nm.

  FIG. 32 shows the X-ray fluorescence analysis results for Sample 9, Sample 10, and Sample 11 by the same method as in Example 1. As a result, a chalcogen compound close to the target composition ratio (Cu: In: Ga: Se = 1: 0.7: 0.3: 2) was obtained for Sample 9, Sample 10, and Sample 11. ,confirmed.

A solution prepared by dissolving 0.01 mol of copper nitrate and 0.01 mol of indium nitrate in 200 ml of pure water so that the atomic ratio of Cu to In (Cu: In) was 1: 1 was placed in a 250 ml flask. Subsequently, a saturated solution of oxalic acid having a solution temperature of 20 ° C. was dropped while being stirred in a state where a wing having a diameter of 5 cm was rotated and stirred at 300 rpm in the flask, thereby producing a coprecipitate of oxalate. The dropwise addition of the oxalic acid solution was continued until the pH of the solution reached 8.5. Thereafter, the coprecipitate and the solution were filtered using a Nutsche to obtain an oxalate cake. The oxalate cake was then vacuum dried at 50 ° C. 5 g of this dried oxalate was put into a 250 ml three-necked flask, and 75 g of propylene glycol (PEG) as a reducing solvent was further added, and a wing with a diameter of 5 cm was rotated and stirred at 300 rpm, and 100 ml / min with nitrogen. Then, Se powder (chalcogen source) was added excessively so that the atomic ratio of Cu to Se (Cu: Se) was 1: 2.1 to obtain a mixed solvent. In this state, the mixed solvent was heated at 10 reaction temperatures shown in FIG. 33 at 150 ° C. to 300 ° C. for 10 hours to try to produce a chalcogen compound. Thereafter, the mixed solvent containing reactive organisms is filtered using Nutsche to obtain a cake, and then the cake is redispersed with pure water, and the filtration is further repeated. The conductivity of the filtrate is 10 ⁻² Sm ^−1. The powder was vacuum dried as follows. The obtained chalcogen compound powder (sample 1 to sample 10) was evaluated in the same manner as in Example 1.

FIG. 33 shows this result. From the X-ray diffraction evaluation results, it was confirmed that CuIn _0.5 Ga _0.5 Se ₂ was obtained. In order to produce a sufficient amount of chalcogen compound (CuIn _0.5 Ga _0.5 Se ₂ ), it has been found that a reaction temperature of at least 220 ° C. or higher is required during the chalcogenation reaction. Moreover, as a result of investigating the particle size of the chalcogen compound powder prepared in Sample 8, Sample 9, and Sample 10 with TEM, the average particle size (D _TEM ) was 7 nm to 13 nm.

FIG. 34 is a graph showing the X-ray analysis result of the chalcogen compound (sample 8) by the same method as in Example 1, and FIG. 35 is the analysis result of fluorescent X-ray by the same method as in Example 1. From these, no peak other than the peak indicating that it is CuIn _0.5 Ga _0.5 Se ₂ was observed in sample 8 (FIG. 34), and the target composition ratio (Cu : In: Ga: Se = 1: 0.5: 0.5: 2) It was confirmed that the chalcogen compound close | similar to was obtained (FIG. 35).

It is a flowchart explaining embodiment of this invention. It is the result of having evaluated the particle size and state of the sample by Example 1 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 1 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 1 of this invention. It is the result of the analysis by the fluorescent X ray of the chalcogen compound by Example 1 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound about the comparative example of Example 1 of this invention. It is the result of having evaluated the particle size and state of the sample by Example 2 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 2 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 2 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 2 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 3 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 3 of this invention. It is the result of the analysis by the fluorescent X ray of the chalcogen compound by Example 3 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 4 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 4 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 4 of this invention. It is the result of evaluating the production | generation state of the chalcogen compound by Example 5 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 5 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 6 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 6 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 6 of this invention. It is the result of having evaluated the particle size and state of the sample by Example 7 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 7 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 7 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 7 of this invention. It is the result of having evaluated the particle size and state of the sample by Example 8 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 8 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 8 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 9 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 9 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 10 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 10 of this invention. It is the result of having evaluated the production | generation state of the chalcogen compound by Example 11 of this invention. It is a graph which shows the X-ray-diffraction result of the chalcogen compound by Example 11 of this invention. It is a result of the analysis by the fluorescent X ray of the chalcogen compound by Example 11 of this invention.

Claims (11)

A compound containing a metal hydroxide or a metal compound powder of a metal oxide and a simple substance selected from sulfur, selenium, and tellurium, or one or more selected from the above element group in a reducing solvent having a boiling point of 200 ° C. or higher Adding a solvent to form a mixed solvent;
Heating the mixed solvent at a temperature of 200 ° C. to 500 ° C .;
The manufacturing method of the chalcogen compound powder characterized by comprising. The method for producing a chalcogen compound powder according to claim 1, wherein the mixed solvent is heated at 220C to 400C. The said metal compound powder contains the compound selected from the group which consists of a transition metal element, a group III metal element, and a group VI metal element, The manufacture of the chalcogen compound powder of Claim 1 or Claim 2 characterized by the above-mentioned. Method. The transition metal element is one of Fe, Co, Cu, Cr, Mn, Ni, Cd, Zn, Ti, V, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, and Yb. It contains the above, The manufacturing method of the chalcogen compound powder of Claim 3 characterized by the above-mentioned. The said group III metal element contains Al, Ga, Tl, and In, The manufacturing method of the chalcogen compound powder of Claim 3 characterized by the above-mentioned. The said VI group metal element contains Sn and Pb, The manufacturing method of the chalcogen compound powder | flour of Claim 3 characterized by the above-mentioned. The method for producing a chalcogen compound powder according to claim 1 or 2 , wherein the reducing solvent is an alcohol solvent having a boiling point in the range of 220 ° C to 400 ° C. The chalcogen compound powder according to claim 1 or 2 , wherein the metal oxide is obtained by a dehydration reaction of a hydroxide that heats the metal hydroxide within a range of 70 ° C to 300 ° C. Manufacturing method. The method for producing a chalcogen compound powder according to claim 1 or 2 , wherein the metal compound powder is produced by dissolving a metal salt in a solvent and adding an alkali. The method for producing a chalcogen compound powder according to claim 9 , wherein the metal salt is selected from the group consisting of a metal halide, a metal carboxylate, a metal carbonate, a metal nitrate, and a metal sulfate. . The method for producing a chalcogen compound powder according to any one of claims 1 to 10, wherein the mixed solvent is heated at a temperature not exceeding the boiling point of the reducing solvent.