JP6286033B2 - Phosphorescent organic light-emitting device having a hole-transporting host in the light-emitting region - Google Patents

Description

  The present invention relates to organic electroluminescent (EL) devices, such as organic light emitting devices (abbreviated herein as OLEDs) and materials that can be used in such OLEDs.

  OLEDs having an organic thin film that includes a light-emitting layer disposed between an anode and a cathode are known in the art. In such devices, light emission can be derived from exciton energy generated by recombination of holes and electrons injected into the light emitting layer.

  OLEDs use a thin organic film that emits light when a voltage is applied across the device. In general, an OLED consists of several organic layers, at least one of which can be made to be electroluminescent (electroluminescence) by applying a voltage across the device. When a voltage is applied across the device, the cathode effectively reduces (ie, injects electrons) the organic layer adjacent to it, and the anode effectively oxidizes (ie, injects holes) the adjacent organic layer. To do. Holes and electrons move across the device to the oppositely charged electrode. When holes and electrons are localized on the same molecule, recombination is said to occur and excitons are formed. An exciton is a localized electron-hole pair having an excited energy state. Light is emitted when excitons are relaxed by an emission mechanism in an electroluminescent compound (ie, electroluminescence). In some cases, excitons can be localized on excimers or exciplexes.

U.S. Pat.No. 5,247,190 U.S. Pat.No. 5,707,745 U.S. Patent No. 6,091,195 U.S. Pat.No. 5,834,893 U.S. Patent No. 6,013,982 U.S. Patent No. 6,087,196 U.S. Pat.No. 6,337,102 U.S. Patent No. 7,431,968 U.S. Patent No. 6,294,398 U.S. Patent 6,468,819 U.S. Pat.No. 7,279,704 International Publication No. 2010/028151 US Patent Application Publication No. 2006/0280965 A1 International Publication No.2009 / 021126 International Publication No. 2010/083359 U.S. Patent Application No. 10 / 233,470 U.S. Patent 6,548,956

Kwong and Alleyene, Triphenylene Hosts in Phosphorescent Light Emitting Diodes, 2006, p. 60

  Despite recent discoveries such as the use of efficient heavy metal phosphorescent emitters and the resulting development of OLED technology, there is a continuing need for longer-term device stability and higher efficiency. Improved OLED devices that exhibit improved lifetime and efficiency are disclosed herein along with related materials that can be used to construct such OLEDs.

  As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that can be used to make organic optoelectronic devices. As used herein, “small molecule” refers to any organic material that is not a polymer (ie, an organic material having a molecule with a defined molecular weight), and “small molecule” is actually It can be very large. Small molecules may include repeat units (eg, oligomers) in some situations. For example, using a long chain alkyl group as a substituent does not exclude a molecule from the “small molecule” group. Small molecules may be incorporated into the polymer, for example, as pendant groups on the polymer backbone or as part of the backbone. Small molecules can also serve as the core residue of a dendrimer consisting of a series of chemical shells built on the core residue. The core residue of the dendrimer can be a fluorescent or phosphorescent small molecule emitter. Dendrimers can be “small molecules” and all dendrimers currently used in the field of OLED are considered small molecules.

  As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where the first layer is described as “disposed on” the second layer, the first layer is disposed further from the substrate. There may be another layer between the first layer and the second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, even if there are various organic layers between the cathode and the anode, the cathode can be described as “disposed on” the anode.

  As used herein, “solution processable” means dissolved, dispersed, or transported in and / or liquid medium in the form of a solution or suspension. It can be deposited from.

  If the ligand is thought to contribute directly to the photoactive properties of the luminescent material, it can be said to be “photoactive”. If the ligand is believed not to contribute to the photoactive properties of the luminescent material, the ligand can be referred to as “auxiliary”, but the auxiliary ligand can change the properties of the photoactive ligand.

  As used herein and as generally understood by those skilled in the art, the energy level of the first “highest occupied molecular orbital” (HOMO) or “lowest unoccupied molecular orbital” (LUMO) is If one energy level is closer to the vacuum energy level, it is “larger” or “higher” than the second HOMO or LUMO. Since the ionization potential (IP) is measured as negative energy relative to the vacuum level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (smaller negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (smaller negative EA). On the conventional energy level diagram with the vacuum level at the top (top), the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level.

  As used herein, and as generally understood by one of ordinary skill in the art, a first work function is “a work function that is greater than a second work function when the first work function has a larger absolute value. “Big” or “High”. Since the work function is usually measured as a negative value relative to the vacuum level, this means that the “higher” work function is more negative. On the conventional energy level diagram with the vacuum level at the top (top), the “higher” work function is illustrated further away from the vacuum level in the downward direction. Therefore, the definition of HOMO and LUMO energy levels follows conventions that are different from work functions.

（式中、Ａは、置換又は非置換芳香族炭化水素の２価の基、置換又は非置換芳香族へテロ環の２価の基、あるいは置換又は非置換縮合多環式芳香族の２価の基を表し；Ａｒ_１、Ａｒ_２、及びＡｒ_３は同じか異なり、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、あるいは置換又は非置換縮合多環式芳香族基であってよく、Ａ及びＡｒ_２、あるいはＡｒ_２及びＡｒ_３は、単結合を介して、あるいは置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１〜Ｒ_９は同じか異なり、水素原子、重水素原子、フッ素原子、塩素原子、シアノ、ニトロ、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１０及びＲ_１１は同じか異なり、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよい。） [Summary]
The disclosure herein provides an OLED having a light-emitting layer (multi-component light-emitting layer) composed of a plurality of components. In one aspect, the OLED disclosed herein includes an anode electrode, a cathode electrode, and an organic electroluminescent layer (organic electroluminescence layer) disposed between the anode electrode and the cathode electrode. The organic electroluminescent layer includes a host material and a phosphorescent dopant material. The host material includes at least a first host compound and a second host compound, and the first host compound has an indenocarbazole ring structure represented by the following formula H1:

Wherein A is a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of a substituted or unsubstituted condensed polycyclic aromatic Ar ₁ , Ar ₂ , and Ar ₃ are the same or different and are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, or substituted or unsubstituted condensed polycyclic aromatics A and Ar ₂ , or Ar ₂ and Ar ₃ may be bonded to each other through a single bond or through a substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R _{1 to} R ₉ are the same or different and are a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano, nitro, a linear chain of 1 to 6 carbon atoms optionally having a substituent Or branched alkyl, 5-10 carbons optionally having substituents Atom cycloalkyl, optionally substituted 2-6 carbon atoms straight or branched alkenyl, optionally substituted 1-6 carbon atoms straight or branched Branched alkyloxy, optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or non-substituted It may be a substituted fused polycyclic aromatic group, or a substituted or unsubstituted aryloxy, which are bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R ₁₀ and R ₁₁ may be the same or different and may have a linear or branched alkyl of 1 to 6 carbon atoms which may have a substituent, or an optionally substituted 5- Cycloalkyl of 10 carbon atoms, with substituents Linear or branched alkenyl having 2 to 6 carbon atoms, which may have a linear or branched alkyloxy having 1 to 6 carbon atoms which may have a substituent, having a substituent Optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted condensed polycyclic aromatic group, or substituted Or an unsubstituted aryloxy, which may be bonded to each other via a single bond, a substituted or unsubstituted methylene, an oxygen atom, or a sulfur atom to form a ring.)

  In another aspect, the above-described OLED further includes an exciton / electron blocking layer disposed between the electroluminescent layer and the anode, the exciton / electron blocking layer blocking at least one of the excitons or electrons. And a substance which is a compound represented by the general formula H1.

  The inventor has discovered that OLEDs incorporating the teachings disclosed herein exhibit unexpectedly improved color saturation in the emission spectrum.

  The drawings are not necessarily drawn to scale.

FIG. 1 is a schematic diagram of an OLED structure. FIG. 2 is a schematic diagram of an OLED structure according to embodiments disclosed herein, wherein the hole transport compound disclosed herein is used as a hole transport host in a quaternary light emitting layer. FIG. 3 is a schematic diagram of an OLED structure according to another embodiment, wherein the hole transport compound is used as a hole transport host and as an exciton / electron blocking layer in a quaternary light emitting layer. FIG. 4 is an energy ranking diagram of the device of FIG. 2, in which the hole transport compound is used as a hole transport host in a quaternary light emitting layer. FIG. 5 is an energy ranking diagram of the device of FIG. 3, wherein the hole transport compound is used as a hole transport host and as an exciton / electron blocking layer in a quaternary light emitting layer. FIG. 6 is a schematic diagram of an inverted OLED.

  In this disclosure, HIL refers to a hole injection layer; HTL refers to a hole transport layer; EBL refers to an exciton / electron blocking layer that can block excitons and / or electrons; HBL refers to the hole blocking layer; ETL refers to the electron transport layer. The terms electroluminescence and light emission are used interchangeably.

（式中、Ａは、置換又は非置換芳香族炭化水素の２価の基、置換又は非置換芳香族へテロ環の２価の基、あるいは置換又は非置換縮合多環式芳香族の２価の基を表し；Ａｒ_１、Ａｒ_２、及びＡｒ_３は同じか異なり、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、あるいは置換又は非置換縮合多環式芳香族基であってよく、Ａ及びＡｒ_２、あるいはＡｒ_２及びＡｒ_３は、単結合を介して、あるいは置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１〜Ｒ_９は同じか異なり、水素原子、重水素原子、フッ素原子、塩素原子、シアノ、ニトロ、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１０及びＲ_１１は同じか異なり、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよい。） The disclosure herein describes an OLED having an organic electroluminescent layer that includes a phosphorescent dopant dispersed in a host material, the host material including a first host compound and a second host compound. The first host compound is a hole transport host compound represented by the following general formula H1.

Wherein A is a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of a substituted or unsubstituted condensed polycyclic aromatic Ar ₁ , Ar ₂ , and Ar ₃ are the same or different and are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, or substituted or unsubstituted condensed polycyclic aromatics A and Ar ₂ , or Ar ₂ and Ar ₃ may be bonded to each other through a single bond or through a substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R _{1 to} R ₉ are the same or different and are a hydrogen atom, deuterium atom, fluorine atom, chlorine atom, cyano, nitro, a linear chain of 1 to 6 carbon atoms optionally having a substituent Or branched alkyl, 5-10 carbons optionally having substituents Atom cycloalkyl, optionally substituted 2-6 carbon atoms straight or branched alkenyl, optionally substituted 1-6 carbon atoms straight or branched Branched alkyloxy, optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or non-substituted It may be a substituted fused polycyclic aromatic group, or a substituted or unsubstituted aryloxy, which are bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R ₁₀ and R ₁₁ may be the same or different and may have a linear or branched alkyl of 1 to 6 carbon atoms which may have a substituent, or an optionally substituted 5- Cycloalkyl of 10 carbon atoms, with substituents Linear or branched alkenyl having 2 to 6 carbon atoms, which may have a linear or branched alkyloxy having 1 to 6 carbon atoms which may have a substituent, having a substituent Optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted condensed polycyclic aromatic group, or substituted Or an unsubstituted aryloxy, which may be bonded to each other via a single bond, a substituted or unsubstituted methylene, an oxygen atom, or a sulfur atom to form a ring.)

  The resulting OLED exhibits improved saturation in the emission spectrum. According to one aspect of the present disclosure, the host material can also include a third host compound. The second and third host compounds are described below.

  FIG. 1 shows an OLED 100. OLED 100, substrate 110, anode 115, hole injection layer 120, hole transport layer 125, and electron blocking layer 130, light emitting layer 135, hole blocking layer 140, electron transport layer 145, electron injection layer 150, protective layer 155 and cathode 160 may be included. Cathode 160 can be a composite cathode having more than one conductive layer, for example, a first conductive layer 162 and a second conductive layer 164 as shown. The OLED 100 can be made by sequentially depositing the described layers. The properties and functions of these various layers, as well as exemplary materials, are described in more detail in US Pat. No. 7,279,704, columns 6-10, the disclosure of which is hereby incorporated by reference in its entirety.

  Structures and materials not specifically described, such as OLEDs (PLEDs) composed of polymeric materials such as those disclosed in Friend et al. US Pat. No. 5,247,190, which is incorporated by reference in its entirety. ), Can also be used. As a further example, an OLED having a single organic layer can be used. OLEDs may be stacked as described, for example, in Forrest et al., US Pat. No. 5,707,745, which is incorporated by reference in its entirety. The structure of the OLED may deviate from the simple layered structure described in this disclosure. For example, the substrate may be a mesa structure as described in US Pat. No. 6,091,195 to Forrest et al., Which is incorporated by reference in its entirety, and / or to improve out-coupling. It may include an angled reflective surface, such as the pit structure described in US Pat. No. 5,834,893 to Bulovic et al., Which is incorporated by reference in its entirety.

  Unless otherwise noted, any of the various embodiment layers may be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, ink jet (eg, described in US Pat. No. 6,013,982 and US Pat. No. 6,087,196, which are incorporated by reference in their entirety), Organic vapor phase deposition (OVPD) (described, for example, in Forrest et al. US Pat. No. 6,337,102, which is incorporated by reference in its entirety), as well as organic vapor jet printing OVJP), for example, as described in US Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based methods. Solution based methods are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include vapor deposition through a mask, cold welding (eg, as described in US Pat. No. 6,294,398 and US Pat. No. 6,468,819, which are incorporated by reference in their entirety), and inkjet And patterning associated with some of the deposition methods such as OVJD. Other methods can also be used. The deposited materials may be modified to adapt them to a particular deposition method. For example, substituents such as branched and unbranched, preferably alkyl and aryl groups containing at least 3 carbons, can be used in small molecules to enhance solution processability. Substituents having 20 or more carbons may be used, with 3-20 carbons being a preferred range. A material with an asymmetric structure may be more suitable for solution processability than one with a symmetric structure, because an asymmetric material may have a smaller tendency to recrystallize. Dendrimer substituents can be used to increase the ability of small molecules to undergo solution processing.

  Devices manufactured according to embodiments of the present invention can be incorporated into a variety of consumer products, including flat panel displays, computer monitors, televisions, billboards, indoor or outdoor lights, and / or Signal lights, head-up displays, fully transparent displays, flexible displays, laser printers, telephones, mobile phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, Includes microdisplays, vehicles, large area walls, cinema or stadium screens, or signs. Various control mechanisms can be used to control devices manufactured in accordance with the present invention, including passive matrices and active matrices. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 ° C. to 30 ° C., more preferably room temperature (20-25 ° C.).

  The materials and structures described herein may have application in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can use these materials and structures. More generally, organic devices, such as organic transistors, can use these materials and structures.

  The terms halo, halogen, alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclic group, aryl, aromatic group, and heteroaryl are known in the art and are described in U.S. Pat. Defined in column 32, the disclosure of which is hereby incorporated by reference in its entirety. The host material of the light emitting layer in the organic light emitting device provides a solid medium for transport and recombination of charge carriers injected from the anode and cathode. The compounds used for the host material can be classified according to their charge transport properties. Some host compounds are primarily electron transportable, and some others are primarily hole transportable. Although the host compound can be characterized as primarily transporting one type of charge, the compound can also transport both types of charge.

[Luminescent dopant]
Any suitable phosphorescent dopant can be used in the light emitting layer. Some examples are shown in Table 5 below. In one embodiment, the phosphorescent dopant is a phosphorescent material that includes a phosphorescent organometallic compound that emits phosphorescent radiation from a triplet excited state when a voltage is applied across the material. The choice of host material depends on the choice of phosphorescent dopant. In some embodiments, the electroluminescent layer includes an additional dopant.

  According to one embodiment, the phosphorescent emitter material is an organometallic compound selected from the group consisting of a phosphorescent organometallic platinum compound, an organometallic iridium compound, and an organometallic osmium compound. The phosphorescent organometallic compound can include a carbon-metal bond. The organometallic platinum compound, iridium compound, and osmium compound can each contain an aromatic ligand.

  The phosphorescent organometallic compound can include a heteroleptic complex with a broad conjugation on the heterocycle. Examples of such heteroleptic iridium compounds are described in PCT International Publication No. 2010/028151, published March 11, 2010, the disclosure of which is hereby incorporated by reference in its entirety. .

（式中、Ａは、置換又は非置換芳香族炭化水素の２価の基、置換又は非置換芳香族へテロ環の２価の基、あるいは置換又は非置換縮合多環式芳香族の２価の基を表し；Ａｒ_１、Ａｒ_２、及びＡｒ_３は同じか異なり、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、あるいは置換又は非置換縮合多環式芳香族基であってよく、Ａ及びＡｒ_２、あるいはＡｒ_２及びＡｒ_３は、単結合を介して、あるいは置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１〜Ｒ_９は同じか異なり、水素原子、重水素原子、フッ素原子、塩素原子、シアノ、ニトロ、置換基を有していてよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよく；Ｒ_１０及びＲ_１１は同じか異なり、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキル、置換基を有していてもよい５〜１０の炭素原子のシクロアルキル、置換基を有していてもよい２〜６の炭素原子の直鎖又は分枝状のアルケニル、置換基を有していてもよい１〜６の炭素原子の直鎖又は分枝状のアルキルオキシ、置換基を有していてもよい５〜１０の炭素原子のシクロアルキルオキシ、置換又は非置換芳香族炭化水素基、置換又は非置換芳香族へテロ環基、置換又は非置換縮合多環式芳香族基、あるいは置換又は非置換アリールオキシであってよく、これらは単結合、置換又は非置換メチレン、酸素原子、又は硫黄原子を介して互いに結合して環を形成していてもよい。 [Hole transporting host compound]
The first host compound is represented by the general formula H1 below.

Wherein A is a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of a substituted or unsubstituted condensed polycyclic aromatic Ar ₁ , Ar ₂ , and Ar ₃ are the same or different and are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, or substituted or unsubstituted condensed polycyclic aromatics A and Ar ₂ , or Ar ₂ and Ar ₃ may be bonded to each other through a single bond or through a substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R _{1 to} R ₉ are the same or different and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, cyano, nitro, a straight chain of 1 to 6 carbon atoms which may have a substituent, or Branched alkyl, optionally substituted 5-10 carbons A cycloalkyl, a linear or branched alkenyl of 2 to 6 carbon atoms which may have a substituent, a linear or branched chain of 1 to 6 carbon atoms which may have a substituent Branched alkyloxy, optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or non-substituted It may be a substituted fused polycyclic aromatic group, or a substituted or unsubstituted aryloxy, which are bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. R ₁₀ and R ₁₁ may be the same or different and may have a linear or branched alkyl of 1 to 6 carbon atoms which may have a substituent, or an optionally substituted 5- A cycloalkyl of 10 carbon atoms, having a substituent Linear or branched alkenyl having 2 to 6 carbon atoms, which may have a linear or branched alkyloxy having 1 to 6 carbon atoms, which may have a substituent Optionally substituted cycloalkyloxy of 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted condensed polycyclic aromatic group, or substituted or They may be unsubstituted aryloxy, which may be bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring.

Examples of specific compounds having the structure of formula H1 are shown below. The first host compound can be selected from the group consisting of the compounds shown below, wherein D represents deuterium.

  Preferably, the HOMO level of the first host compound is relatively close to the HOMO level of the emitter dopant, which allows the hole transport function load to be removed from the emitter dopant material. This increases the lifetime of the emitter dopant material in the OLED. Since the first host compound is a hole transport type, the HOMO level of the first host compound is higher than the HOMO energy level of the other host compounds (smaller electronegativity). This correct energy level alignment allows charge and excitons to separate in the device emissive layer, minimizing triplet-polaron annihilation and non-luminescent quencher formation. This improves the saturation of the OLED in the emission spectrum.

[Synthesis of Example of First Host Compound H1]

Example 1: Synthesis of compound H1-1
Synthesis of 12,12-dimethyl-10-phenyl-7- (9-phenyl-9H-carbazol-3-yl) -10,12-dihydroindeno [2,1-b] carbazole
Put N- (9,9-dimethyl-9H-fluoren-2-yl) -2-bromoaniline (18.5 g), potassium acetate (6.98 g), and DMF (95 ml) in a nitrogen-substituted reaction vessel, Gas was bubbled for 1 hour. Tetrakis (triphenylphosphine) palladium (1.18 g) was added and the mixture was heated and stirred at 100 ° C. for 11 hours. After the mixture was cooled to room temperature, the reaction solution was added to water (300 ml) and extracted with toluene (300 ml). The obtained organic layer was washed twice with water (200 ml), dehydrated with anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel; eluent: toluene / n-hexane) to give 12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (7.9 g; yield 55.2%).

  The resulting 12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (7.8 g), iodobenzene (3.7 ml), sodium sulfite (0.43 g), powdered copper (0.17 g), 3,5-Di (tert-butyl) salicylic acid (0.69 g), potassium carbonate (5.71 g), and dodecylbenzene (10 ml) were placed in a reaction vessel purged with nitrogen, heated, and stirred at 170 ° C. for 10 hours. The mixture is cooled to 100 ° C., extracted by adding toluene (100 ml), concentrated under reduced pressure, crystallized using n-hexane (30 ml), and 12,12-dimethyl-10-phenyl. A pale yellow powder of -10,12-dihydroindeno [2,1-b] carbazole was obtained (8.73 g; yield 88.3%).

  The resulting 12,12-dimethyl-10-phenyl-10,12-dihydroindeno [2,1-b] carbazole (7.5 g) and DMF (53 ml) were placed in a reaction vessel. N-bromosuccinimide (3.72 g) was added under ice-cooling conditions and the mixture was stirred for 9 hours and then left overnight. Water (260 ml) is added and the mixture is filtered through 7-bromo-12,12-dimethyl-10-phenyl-10,12-dihydroindeno [2,1-b] carbazole brownish white powder (8.67 g; yield 94.6%).

  The obtained 7-bromo-12,12-dimethyl-10-phenyl-10,12-dihydroindeno [2,1-b] carbazole (2.0 g), 9-phenyl-3- (4,4,5, 5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9H-carbazole (1.68 g), toluene / ethanol (4/1, v / v) mixed solvent (15 ml), and 2M aqueous potassium carbonate solution (3.4 ml) was placed in a reaction vessel purged with nitrogen, and nitrogen gas was passed for 30 minutes under ultrasonic irradiation. Tetrakis (triphenylphosphine) palladium (0.26 g) was added and the mixture was heated and stirred at 73 ° C. for 5 hours. The mixture was cooled to room temperature, toluene (30 ml) and water (20 ml) were added, and liquid separation was performed to collect the organic layer. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain a crude product. The crude product was purified by chromatography (carrier: silica gel; eluent: toluene / n-hexane) to give 12,12-dimethyl-10-phenyl-7- (9-phenyl-9H-carbazol-3-yl ) -10,12-dihydroindeno [2,1-b] carbazole was obtained as a white powder (1.5 g; yield 54.7%).

The structure of the obtained white powder was identified by NMR. ^The 32 hydrogen signals detected by ¹ H-NMR (THF-d ₈ ) are as follows. δ (ppm) = 8.66 (1H), 8.64 (1H), 8.59 (1H), 8.23-8.29 (1H), 7.88-7.90 (1H), 7.83-7.85 (1H), 7.78-7.80 (1H), 7.66- 7.71 (8H), 7.42-7.53 (7H), 7.37-7.40 (1H), 7.31-7.33 (1H), 7.26-7.29 (1H), 7.21-7.24 (1H), 1.51 (6H).

Example 2: Synthesis of compound H1-118
Synthesis example of 10- (biphenyl-4-yl) -12,12-dimethyl-7- (9-phenyl-9H-carbazol-3-yl) -10,12-dihydroindeno [2,1-b] carbazole 12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (35.5 g), 4-bromobiphenyl (35.0 g), sodium bisulfite (6.0 g), powdered copper ( 2.4 g), 3,5-di (tert-butyl) salicylic acid (9.4 g), potassium carbonate (31.2 g), and dodecylbenzene (52 ml) were placed in a reaction vessel purged with nitrogen, heated, and heated at 190 ° C. Stir for hours. After cooling to 120 ° C., toluene (35 ml) was added and the mixture was stirred and the crude product was collected by filtration. Toluene (1.6 L) was added to the crude product, and then the crude product was heated and extracted at 110 ° C. After cooling to room temperature, the crude product was concentrated under reduced pressure. The product was crystallized from methanol (120 ml) to give a white powder of 10- (biphenyl-4-yl) -12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (48.5 g; yield 88.1%).

  The obtained 10- (biphenyl-4-yl) -12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (42.5 g) and DMF (2.5 L) were placed in a reaction vessel, The mixture was heated to 70 ° C to dissolve. After cooling to room temperature, N-bromosuccinimide (17.4 g) was added and the mixture was stirred for 7 hours. Water (2.5 L) was added, filtered, and 10- (biphenyl-4-yl) -7-bromo-12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole White powder was obtained (34.9 g; yield 69.5%).

  The obtained 10- (biphenyl-4-yl) -7-bromo-12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (16.5 g), 9-phenyl-3- ( 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9H-carbazole (14.2 g), toluene / ethanol (4/1, v / v) mixed solvent (250 ml) And a 2M aqueous potassium carbonate solution (48 ml) were placed in a reaction vessel purged with nitrogen, and nitrogen gas was bubbled for 30 minutes under ultrasonic irradiation. Tetrakis (triphenylphosphine) palladium (1.9 g) was added and the mixture was heated and stirred at 73 ° C. for 5 hours. After the mixture was cooled to room temperature, the precipitated crude product was collected by filtration. 1,2-Dichlorobenzene (450 ml) was added to the crude product, the crude product was dissolved while heating, the insoluble material was removed by filtration, and the filtrate was concentrated under reduced pressure. Purification by crystallization using 1,2-dichlorobenzene (150 ml) and n-hexane (300 ml) gave 10- (biphenyl-4-yl) -12,12-dimethyl-7- (9-phenyl- A white powder of 9H-carbazol-3-yl) -10,12-dihydroindeno [2,1-b] carbazole was obtained (9.8 g; yield 45.2%).

The structure of the obtained white powder was identified by NMR. ^The 36 hydrogen signals detected by ¹ H-NMR (THF-d ₈ ) are as follows. δ (ppm) = 8.69 (1H), 8.64 (1H), 8.59 (1H), 8.28 (1H), 7.99 (2H), 7.89 (1H), 7.85-7.78 (6H), 7.66 (4H), 7.56-7.49 (6H), 7.44-7.37 (4H), 7.32 (1H), 7.27 (1H), 7.23 (1H), 1.52 (6H).

Example 3: Synthesis of H1-119
12,12-Dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -7- (9-phenyl-9H-carbazol-3-yl) -10,12-dihydroindeno [2, Synthesis of 1-b] carbazole 12,12-dimethyl-10,12-dihydroindeno [2,1-b] carbazole (5.5 g) synthesized in Example 1, 2-bromo-9,9-dimethyl-9H- Fluorene (6.4 g), sodium bisulfite (0.3 g), powdered copper (0.1 g), 3,5-di (tert-butyl) salicylic acid (0.5 g), potassium carbonate (4.0 g), and dodecylbenzene (5 ml) )) Was placed in a reaction vessel purged with nitrogen, heated and stirred at 180 ° C. for 29 hours. The mixture was cooled to 100 ° C., toluene (80 ml) was added, insoluble matters were removed by filtration, and the filtrate was concentrated. Crystallization was performed using n-hexane (20 ml), and 12,12-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -10,12-dihydroindeno [2,1 -b] A tan powder of carbazole was obtained (7.4 g; yield 80.0%).

  The resulting 12,12-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -10,12-dihydroindeno [2,1-b] carbazole (7.0 g) and DMF (140 ml) was placed in a reaction vessel. The mixture was heated to 100 ° C. to dissolve and cool. N-bromosuccinimide (2.6 g) was added under ice-cooling conditions and the mixture was stirred at room temperature for 1 hour. Water (500 ml) is added and the mixture is filtered to give 7-bromo-12,12-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -10,12-dihydroindeno. A light red powder of [2,1-b] carbazole was obtained (5.7 g; yield 70.3%).

  Obtained 7-bromo-12,12-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -10,12-dihydroindeno [2,1-b] carbazole (4.0 g) 9-phenyl-3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9H-carbazole (3.2 g), toluene / ethanol (4/1, v / v)) A mixed solvent (50 ml) and a 2M aqueous potassium carbonate solution (10 ml)) were placed in a reaction vessel purged with nitrogen, and nitrogen gas was bubbled for 30 minutes under ultrasonic irradiation. Tetrakis (triphenylphosphine) palladium (0.4 g) was added and the mixture was heated and stirred at 71 ° C. for 7 hours. After the mixture was cooled to room temperature, water (20 ml) was added and liquid separation was performed to collect the organic layer. The organic layer was dehydrated with anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel; eluent: toluene / cyclohexane) to give 12,12-dimethyl-10- (9,9-dimethyl-9H-fluoren-2-yl) -7- A white powder of (9-phenyl-9H-carbazol-3-yl) -10,12-dihydroindeno [2,1-b] carbazole was obtained (3.4 g; yield 65.7%).

The structure of the obtained white powder was identified by NMR. ^The 40 hydrogen signals detected by ¹ H-NMR (THF-d ₈ ) are as follows. δ (ppm) = 8.67 (1H), 8.65 (1H), 8.60 (1H), 8.28 (1H), 8.08 (1H), 7.90-7.82 (5H), 7.69-7.66 (5H), 7.58-7.49 (5H) , 7.43 (2H), 7.39 (2H), 7.36 (1H), 7.33 (1H), 7.28 (1H), 7.23 (1H), 1.61 (6H), 1.51 (6H).

式中、X¹〜X⁸はC又はNから選択され；Z¹及びZ²はS又はOである。好ましくは、第二のホスト化合物及び第三のホスト化合物は異なる化合物である。 Second and third host compounds Each of the second and third host compounds is a wide bandgap host compound having a higher electron transporting property than compound H1, and at least one of the following groups in the molecule: Can be included.

Wherein X ^{1 to} X ⁸ are selected from C or N; Z ¹ and Z ² are S or O. Preferably, the second host compound and the third host compound are different compounds.

According to aspects of the disclosure herein, any substituents in the second and third host compounds are preferably C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1) 2, n (} Ar 1) (Ar 2), CH = CHC n H 2n + 1, C = CHC n H 2n + 1, Ar 1, Ar 1 -Ar 2, C n H 2n - A non-condensed substituent independently selected from the group consisting of Ar ₁ or unsubstituted, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs.

  According to another aspect, the second host compound can be a compound comprising triphenylene with benzofused thiophene. Triphenylene is a polycyclic aromatic hydrocarbon with high triplet energy, yet high [π] conjugation, and a relatively small energy difference between the first singlet and the first triplet level . This indicates that triphenylene has relatively readily available HOMO and LUMO levels compared to other aromatic compounds with similar triplet energy (eg, biphenyl). Yes. The advantage of using triphenylene and its derivatives as a host is that it is compatible with even red, green, and blue phosphorescent dopants and can provide high efficiency without energy quenching. A triphenylene host can be used to provide a highly efficient and stable phosphorescent OLED (PHOLED). See Kwong and Alleyene, Triphenylene Hosts in Phosphorescent Light Emitting Diodes, 2006, p. 60, US Patent Application Publication No. 2006/0280965 A1. Benzo-fused thiophenes can be used as hole transporting organic conductors. Furthermore, the triplet energies of benzothiophenes, namely dibenzo [b, d] thiophene (herein referred to as “dibenzothiophene”), benzo [b] thiophene, and benzo [c] thiophene are relatively high. Combinations of benzofused thiophenes and triphenylene as hosts in PHOLEDs can be advantageous. More specifically, benzofused thiophenes are generally more hole transporting than electron transporting, and triphenylene is more electron transporting than hole transporting. Thus, combining these two parts in a molecule can result in improved charge balance, which can improve device performance with respect to lifetime, efficiency, and low voltage. Using various chemical linkages of the two parts to adjust the properties of the resulting compound to make it most suitable for a particular phosphor, device structure and / or manufacturing process. Can do. For example, m-phenylene linking groups are expected to provide higher triplet energy and greater solubility, whereas p-phenylene linking groups are expected to provide lower triplet energy and less solubility. Is done.

  Similar to the properties of benzofused thiophenes, benzofused furans are generally hole transport materials with relatively high triplet energy. Examples of the benzo-fused furans include benzofuran and dibenzofuran. Therefore, a material containing both triphenylene and benzofuran can be advantageously used as a phosphor host or hole blocking material in a PHOLED. Compounds containing both of these two groups provide improved electronic stabilization, which can improve device stability and efficiency at low voltages. The properties of benzofuran compounds with triphenylene can be adjusted as needed by using different chemical linkages to join triphenylene and benzofuran.

The compound for the second host compound may be substituted with groups that are not necessarily triphenylenes, benzo-fused thiophenes, and benzo-fused furans. Preferably, any group used as a substituent of the compound has a triplet energy high enough to maintain the advantage of having a triphenylenebenzofused thiophene or benzofused furan (ie, the substituent's Triplet energy maintains the high triplet energy of benzo-fused thiophenes, benzo-fused furans, and triphenylenes). Examples of such groups that can be used as substituents in the above compounds include C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) Independently selected from the group consisting of (Ar ₂ ), CH = CH—C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ Any non-condensed substituent, or unsubstituted, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, Ar ₁ and Ar ₂ are independently benzene, Selected from the group consisting of biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs. The compounds for host materials described herein have sufficiently high triplet energy and are suitable for use in devices having phosphorescent blue light emitting materials.

  The substituents of the compounds described herein are non-condensable and therefore they are not fused to the triphenylene, benzo-fused furan, or benzo-fused thiophene moiety of the compound. These substituents may optionally be internally condensed (ie, may be condensed with each other).

  The materials provided herein can also result in improved film formation in the device when made by both vapor deposition and solution processing methods. In particular, materials that result in improved fabrication have a central pyridine ring to which benzo-fused thiophene and triphenylene, or benzofuran and triphenylene are attached. This improved film formation is believed to be the result of a combination of polar and nonpolar rings in the compound.

式（H-IV）中、XはS又はOであり；R₁、R₂、及びR₃は、C_nH_2n+1、OC_nH_2n+1、OAr₁、N(C_nH_2n+1)₂、N(Ar₁)(Ar₂)、CH=CH-C_nH_2n+1、C=CHC_nH_2n+1、Ar₁、Ar₁-Ar₂、C_nH_2n-Ar₁、及び水素からなる群から独立に選択される非縮合置換基であり；nは1、2、3、4、5、6、7、8、9、又は10であり；Ar₁及びAr₂は独立にベンゼン、ビフェニル、ナフタレン、トリフェニレン、カルバゾール、及びそれらのヘテロ芳香族類似体からなる群から選択され；pは1、2、3、又は4であり；R₁、R₂、及びR₃のうち少なくとも１つはトリフェニレン基を含む。 According to another aspect, the second and / or third host compound is a benzo-fused thiophene or benzo-fused furan with triphenylene. Examples of benzo-fused thiophenes or benzo-fused furans having triphenylene include compounds having structures of the following formulas (H-IV), (HV), and (H-VI).

In the formula (H-IV), X is S or O; R ₁ , R ₂ , and R ₃ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n +1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and a non-condensed substituent independently selected from the group consisting of hydrogen; n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; Ar ₁ and Ar ₂ Are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs; p is 1, 2, 3, or 4; R ₁ , R ₂ , and R ₃ At least one of them contains a triphenylene group.

In the formula (HV), X is S or O; R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and hydrogen A non-condensable substituent independently selected from the group; n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; Ar ₁ and Ar ₂ are independently benzene, biphenyl , Naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof; o is 1, 2, 3, or 4; p is 1 or 2; of R ₁ and R ₂ At least one contains a triphenylene group.

In the formula (H-VI), X is S or O; R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and hydrogen A non-condensed substituent independently selected from the group consisting of: n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; Ar ₁ and Ar ₂ are independently benzene , Biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof; o and p are 1, 2, 3, or 4; at least one of R ₁ and R ₂ is Contains a triphenylene group.

式中、XはS又はOである。好ましくは、XはSである。R₁〜R_nは独立に、C_nH_2n+1、OC_nH_2n+1、OAr₁、N(C_nH_2n+1)₂、N(Ar₁)(Ar₂)、CH=CH-C_nH_2n+1、C=CHC_nH_2n+1、Ar₁、Ar₁-Ar₂、C_nH_2n-Ar₁からなる群から独立に選択される非縮合置換基であるか又は非置換である。R₁〜R_nのそれぞれは、モノ、ジ、トリ、又はテトラ置換を表すことができる。nは1、2、3、4、5、6、7、8、9、又は10である。Ar₁及びAr₂は独立にベンゼン、ビフェニル、ナフタレン、トリフェニレン、カルバゾール、及びそれらのヘテロ芳香族類似体からなる群から選択される。R₁、R₂、及びR₃のうち少なくとも１つはトリフェニレン基を含む。 Examples of compounds having the structure of formula (H-IV) include:

In the formula, X is S or O. Preferably X is S. R _{1 to} R _n are independently C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH A non-condensed substituent independently selected from the group consisting of -C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar _1, Unsubstituted. Each of R _{1 to} R _n can represent mono, di, tri, or tetra substitutions. n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs. At least one of R ₁ , R ₂ , and R ₃ contains a triphenylene group.

式中、XはS又はOである。好ましくは、XはSである。R₁〜R_nは独立に、C_nH_2n+1、OC_nH_2n+1、OAr₁、N(C_nH_2n+1)₂、N(Ar₁)(Ar₂)、CH=CH-C_nH_2n+1、C=CHC_nH_2n+1、Ar₁、Ar₁-Ar₂、C_nH_2n-Ar₁からなる群から独立に選択されるか又は非置換である。R₁〜R_nのそれぞれは、モノ、ジ、トリ、又はテトラ置換を表すことができ、nは1、2、3、4、5、6、7、8、9、又は10である。Ar₁及びAr₂は独立にベンゼン、ビフェニル、ナフタレン、トリフェニレン、カルバゾール、及びそれらのヘテロ芳香族類似体からなる群から選択される。R₁、R₂、及びR₃のうち少なくとも１つはトリフェニレン基を含む。 Examples of compounds having the structure of formula (HV) include:

In the formula, X is S or O. Preferably X is S. R _{1 to} R _n are independently C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH -C a _{n H 2n + 1, C =} CHC n H 2n + 1, Ar 1, Ar 1 -Ar 2, or unsubstituted C _n H _2n is selected -Ar from the group consisting of ₁ independently. Each of R _{1 to} R _n can represent mono, di, tri, or tetra substitutions, where n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs. At least one of R ₁ , R ₂ , and R ₃ contains a triphenylene group.

上記式中、XはS又はOである。好ましい態様では、XはSである。R₁〜R_nは独立に、C_nH_2n+1、OC_nH_2n+1、OAr₁、N(C_nH_2n+1)₂、N(Ar₁)(Ar₂)、CH=CH-C_nH_2n+1、C=CHC_nH_2n+1、Ar₁、Ar₁-Ar₂、C_nH_2n-Ar₁からなる群から独立に選択されるか又は非置換である。R₁〜R_nのそれぞれは、モノ、ジ、トリ、又はテトラ置換を表すことができる。nは1、2、3、4、5、6、7、8、9、又は10である。Ar₁及びAr₂は独立にベンゼン、ビフェニル、ナフタレン、トリフェニレン、カルバゾール、及びそれらのヘテロ芳香族類似体からなる群から選択される。R₁、R₂、及びR₃のうち少なくとも１つはトリフェニレン基を含む。 Examples of compounds having the structure of formula (H-VI) include:

In the above formula, X is S or O. In a preferred embodiment, X is S. R _{1 to} R _n are independently C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH -C a _{n H 2n + 1, C =} CHC n H 2n + 1, Ar 1, Ar 1 -Ar 2, or unsubstituted C _n H _2n is selected -Ar from the group consisting of ₁ independently. Each of R _{1 to} R _n can represent mono, di, tri, or tetra substitutions. n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs. At least one of R ₁ , R ₂ , and R ₃ contains a triphenylene group.

  All of the host compound materials disclosed herein are compounds having a triplet energy higher than the triplet energy of the phosphorescent dopant. This energy configuration allows confinement of triplet excited states on the dopant. The use of an additional host material in the light emitting layer can reduce exciton and charge carrier interactions, thereby reducing exciton quenching, which can improve device efficiency and / or lifetime.

  The wide band gap host compound for the second host compound in the light emitting layer has a HOMO-LUMO band gap of at least 2.0 eV. Depending on the phosphorescent dopant used, in some cases the wide band gap host compound has a HOMO-LUMO band gap of at least 2.5 eV and in some cases at least 3.0 eV. In some cases, the HOMO-LUMO bandgap of the wide bandgap host compound is the same as or greater than that of the first host compound with hole transport properties. Wide bandgap host compounds do not easily transport any type of charge in the emissive layer. In particular, the wide band gap host compound has a lower hole mobility than the first host compound having a hole transporting property. It is preferable that the host compound can be well mixed with other components of the light emitting layer and can promote the formation of an amorphous film.

  Information on the synthesis of specific examples of the second host compound described above can be found in PCT International Publication No. 2009/021126 published on February 12, 2009 (the contents of which are incorporated herein) and July 2010. PCT International Publication No. 2010/083359 published on the 22nd, the contents of which are incorporated herein by reference.

  The compound for the light emitting layer can be deposited using any suitable deposition technique, including vapor deposition methods such as vacuum thermal evaporation. The various compounds in the emissive layer can be deposited separately or in combination. For example, each compound may be deposited at an individually controlled rate, or alternatively, two or more host compounds may be premixed and then evaporated together.

  The components of the multi-component light emitting layer discussed here can be used in the following amounts defined as mass% of the total light emitting layer material. According to one embodiment, the phosphorescent dopant may comprise 0.5-20%, more preferably 1-10%, most preferably 3-7%. The first host compound preferably constitutes 25% or less, more preferably about 10-20%. The second host compound preferably comprises about 50-90%, more preferably about 60-80%. The third host compound preferably comprises about 10-50%, more preferably about 20-40%. The relative amounts of luminescent dopant and host material in the luminescent layer will vary depending on the specific application.

Exciton / Electron Blocking Layer According to another aspect, the OLED disclosed herein is formed from a material that is a compound represented by the general formula H1 described above, and is disposed between the light emitting layer and the anode. An electron blocking layer (EBL) can further be included. The EBL blocks at least one or both of excitons and electrons.

  The substance for EBL can be selected from the group consisting of the following examples of compounds having the general formula H1: Compound H1-1, Compound H1-2, Compound H1-3, Compound H1-4, Compound H1- 5, Compound H1-6, Compound H1-7, Compound H1-8, Compound H1-9, Compound H1-10, Compound H1-11, Compound H1-12, Compound H1-13, Compound H1-14, Compound H1- 15, Compound H1-16, Compound H1-17 to Compound H1-120 (these are described herein).

Hole Transport Layer The OLED according to another aspect of the present disclosure further includes at least one hole transport layer disposed between the light emitting layer and the anode. The at least one hole transport layer is a substance including at least one of compounds having a formula selected from the following formulas (HTL-I) to (HTL-VI) listed below.

式中、R₁₁及びR₁₂は同じか異なり、独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、フェニル基、低級アルキル基又は重水素置換を有するフェニル基、及び重水素原子又は低級アルコキシ基置換を有するフェニル基からなる群から選択され、但し、R₁₁及びR₁₂のうち少なくとも１つは、重水素原子、n-ブチル基、イソブチル基、sec-ブチル基、tert-ブチル基、フェニル基、低級アルキル基置換を有するフェニル基、又は低級アルコキシ基置換を有するフェニル基であり；かつ、R₁₃は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表す。 (HTL-I) is the following formula.

In the formula, R ₁₁ and R ₁₂ are the same or different and are independently a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, a phenyl group, a lower alkyl group or a phenyl group having deuterium substitution, and a deuterium atom. Or selected from the group consisting of phenyl groups having lower alkoxy group substitution, provided that at least one of R ₁₁ and R ₁₂ is a deuterium atom, n-butyl group, isobutyl group, sec-butyl group, tert-butyl Group, phenyl group, phenyl group having lower alkyl group substitution, or phenyl group having lower alkoxy group substitution; and R ₁₃ is a hydrogen atom, deuterium atom, lower alkyl group, lower alkoxy group, or chlorine atom Represents.

式中、R_21、R₂₂、及びR₂₃は同じか異なり、それぞれ独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、非置換フェニル基、又は低級アルキル基もしくは低級アルコキシ基を置換基（１又は複数）として有するフェニル基を表し；R₂₄は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表し；
A₁は以下の構造式（a1）〜（i1）のいずれか１つで表される基を表す。

式中、R₂₅は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表す。 (HTL-II) is represented by the following formula.

In the formula, R _21, R ₂₂ , and R ₂₃ are the same or different and each independently represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, an unsubstituted phenyl group, or a lower alkyl group or a lower alkoxy group. Represents a phenyl group as a substituent (s); R ₂₄ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom;
A ₁ represents a group represented by any _one of the following structural formulas (a1) to (i1).

In the formula, R ₂₅ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom.

式中、R_31、R₃₂、及びR₃₃は同じか異なり、それぞれ独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、非置換フェニル基、又は重水素原子、低級アルキル基、もしくは低級アルコキシ基を置換基（１又は複数）として有するフェニル基を表し；R₃₄は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表し；
A₂は以下の構造式（j1）〜（n1）のいずれか１つで表される基を表す。

(HTL-III) is represented by the following formula.

In the formula, R _31, R ₃₂ , and R ₃₃ are the same or different and are each independently a hydrogen atom, deuterium atom, lower alkyl group, lower alkoxy group, unsubstituted phenyl group, or deuterium atom, lower alkyl group, Or a phenyl group having a lower alkoxy group as a substituent (s); R ₃₄ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom;
A ₂ represents a group represented by any one of the following structural formulas (j1) to (n1).

式中、R₄₁及びR₄₂は同じか異なり、それぞれ独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、非置換フェニル基、又は重水素原子、低級アルキル基、もしくは低級アルコキシ基を置換基（１又は複数）として有するフェニル基を表し；R₄₃は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表し；
A₃は以下の構造式（a2）〜（i2）のいずれか１つで表される基を表す。

式中、R₄₄は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表す。 (HTL-IV) is represented by the following formula.

In the formula, R ₄₁ and R ₄₂ are the same or different and each independently represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, an unsubstituted phenyl group, a deuterium atom, a lower alkyl group, or a lower alkoxy group. Wherein R ₄₃ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom;
A ₃ represents a group represented by any one of the following structural formulas (a2) to (i2).

In the formula, R ₄₄ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom.

式中、R₅₁及びR₅₂は同じか異なり、それぞれ独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、非置換フェニル基、又は重水素原子、低級アルキル基、もしくは低級アルコキシ基を置換基（１又は複数）として有するフェニル基を表し；R₅₃は、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、又は塩素原子を表し；
A₄は以下の構造式（j2）〜（n2）のいずれか１つで表される基を表す。

(HTL-V) is the following formula.

In the formula, R ₅₁ and R ₅₂ are the same or different and each independently represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, an unsubstituted phenyl group, a deuterium atom, a lower alkyl group, or a lower alkoxy group. Wherein R ₅₃ represents a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, or a chlorine atom;
A ₄ represents a group represented by any one of the following structural formulas (j2) to (n2).

式中、R₆₁〜R₆₉は同じか異なり、独立に、水素原子、重水素原子、低級アルキル基、低級アルコキシ基、非置換芳香族炭化水素基、又は重水素原子、低級アルキル基、もしくは低級アルコキシ基を有するフェニル基を表し；r₆₁〜r₆₉は同じか異なり、0、1、又は2
を表す。 (HTL-VI) is the following formula.

In the formula, R _{61 to} R ₆₉ are the same or different and independently represent a hydrogen atom, a deuterium atom, a lower alkyl group, a lower alkoxy group, an unsubstituted aromatic hydrocarbon group, a deuterium atom, a lower alkyl group, or a lower group. Represents a phenyl group having an alkoxy group; r _{61 to} r ₆₉ are the same or different and represent 0, 1, or 2;
Represents.

The terms “lower alkyl group” and “lower alkoxy group” used herein mean “C _1-4 alkyl group” and “C _1-4 alkoxy group”, respectively.

  Synthesis information for compounds of formula (HTL-I) to (HTL-VI) and specific examples of compounds of formula (HTL-I) to (HTL-VI) are provided in US Pat. No. 5,707,747 to Tomiyama et al. The contents of which are incorporated herein by reference.

  Examples of compounds having the structures of formulas (HTL-I) to (HTL-VI) include:

Substrate The OLED of the present invention can be made on a substrate for supporting the OLED. The substrate is preferably a flat substrate having a transmittance of at least about 50% for light in the visible region of about 400 to about 700 nm. The substrate includes a glass plate, a polymer plate and the like. In particular, the glass plate includes soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz and the like. The polymer plate includes polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like.

Electrode The anode 3 of the OLED 100 of the present invention may have a role of injecting holes into the hole injection layer, the hole transport layer, or the light emitting layer. Typically, the anode has a work function of 4.5 eV or higher. Specific examples of materials suitable for use as the anode include indium tin oxide alloys (ITO), tin oxide (NESA), indium zinc oxide, gold, silver, platinum, copper, and the like. The anode can be made by forming a thin film from an electrode material such as those discussed above by methods such as vapor deposition, sputtering, and the like.

  When light is emitted from the light emitting layer, the light transmittance in the visible light region at the anode is preferably greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. The thickness of the anode is selected according to the material, and is generally in the range of about 10 nm to about 1 μm, preferably about 10 nm to about 200 nm.

  The cathode 11 preferably comprises a material having a small work function for the purpose of injecting electrons into the electron injection layer, the electron transport layer, or the light emitting layer. Materials suitable for use as the cathode include indium, aluminum, magnesium, magnesium-indium alloys, magnesium-aluminum alloys, aluminum-lithium alloys, aluminum-scandium-lithium alloys, magnesium-silver alloys, and the like. It is not limited. For transparent or top-emitting devices, TOLED cathodes such as those disclosed in US Pat. No. 6,548,956 are preferred.

  The cathode can be formed by forming a thin film by a method such as vapor deposition or sputtering as in the case of the anode. Further, an embodiment in which light emission is extracted from the cathode side can be used in the same manner.

Reverse structure OLED
FIG. 6 illustrates an inverted OLED 400 according to another embodiment disclosed herein. The device includes a substrate 410, a cathode 415, a light emitting layer 420, a hole transport layer 425, and an anode 430. The OLED 400 can be made by sequentially depositing the described layers. Since the most common OLED configuration has a cathode disposed above the anode and the device 400 has a cathode 415 disposed below the anode 430, the device 400 can be referred to as an inverted OLED. OLED 400 also illustrates an example of an OLED in which some of the layers illustrated in OLED 100 of FIG. 1 are omitted from the device structure.

  It will be appreciated that simple layered structures of OLEDs 100, 200, 300, and 400 are provided as non-limiting examples, and embodiments of the present invention can be used in conjunction with a wide range of other structures. The specific materials and structures described are exemplary in nature and other materials and structures can be used. Based on design, performance, and cost factors, a practical OLED can be realized in various ways by combining the various layers described above, or some layers may be omitted entirely. Other layers not specifically described may also be included.

  Although many of the examples described herein describe various layers as containing a single material, it is understood that combinations of materials, or more generally mixtures, may be used. The The layer may also have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in the device 400, the hole transport layer 425 transports holes and injects holes into the light emitting layer 420 and can be described as a hole transport layer or as a hole injection layer. In one embodiment, an OLED can be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer or may further comprise multiple layers of various organic materials as described.

The invention will be described in more detail with reference to the following example devices and comparative devices. However, the present invention is not limited to the following examples. The chemical structures of the specific organic compounds H1-1, H1-118, H1-119, H, E1, G1, NPD, and Alq ₃ used to fabricate the example devices are shown below.

[Compound H1 as host-Example devices # 1, # 2, and # 3]
An example green PHOLED having a four-component light emitting layer and having the structure shown in FIG. 2 was constructed. Example devices # 1, # 2, and # 3 had an ITO anode (800 mm) and a LiF / Al cathode. The following layers were deposited between the two electrodes: 100 mm thick hole injection layer (HIL) made of compound LG-101 (from LG Chemical), 500 mm thick made of NPD Electron blocking layer (EBL), 300 mm thick quaternary light emitting layer (EML), 100 mm thick hole blocking layer (HBL) made of compound E1, and 400 mm made of Alq ₃ Thick electron transport layer. The four component EML in these test devices was formed using three host compounds. The first host compound is a hole transport host compound having the general formula H1, the second host compound is compound H as a wide bandgap matrix host, and the third host compound is E1 as an electron transport host. was. As shown in the summary of test device data in Table 3, specific hole transport host compounds in devices # 1, # 2, and # 3 are H1-1, H1-119, and H1-118, respectively. was. Compound G1 was a green phosphor dopant. The HOMO-LUMO energy levels of these compounds are shown in Table 1 below.

  The functions of the organic compounds used in the exemplary devices according to the disclosure herein are shown in Table 2 below.

  The amount of each component of the light emitting layer used is shown in Table 3 below. Those amounts are shown in mass% in the light emitting layer. For example, in the exemplary device # 1, the concentrations of the first host compound H1-1, the second host compound H, the third host compound E1, and the light emitter dopant G1 are 15 mass%, 60 mass%, and 20 mass%, respectively. % By mass and 5% by mass.

  An energy level diagram for the four component EML of the device of FIG. 2 incorporating the hole transporting host H1 as one of the hosts in the EML according to one embodiment is shown in FIG. An energy level diagram for the four component EML portion of exemplary device # 4 is shown in FIG. Compound H1-1 has a HOMO level of 5.59 eV, which is higher (ie, more electrical) than the HOMO levels of other host compounds H and E1 (these are 5.96 and 5.73, respectively). Small negative degree). Therefore, the host compounds H and E1 are more electron transporting than the hole transporting compounds H1-1, H1-118, and H1-119. The HOMO levels of compounds H1-1, H1-118, and H1-119 are relatively close to the HOMO level (5.1 eV) of the emitter dopant G1, and as discussed above, this is a hole transport host. Compounds, such as H1-1, H1-118, and H1-119, allow the hole transport function load to be removed from the emitter dopant, which extends the lifetime of the emitter dopant material.

  In example devices # 1 to # 8 with high 15% by weight of compounds H1-1, H1-118, and H1-119 and low 5% by weight of G1 in EML, most of the holes are hole transporting host compounds Transported by H1-1, H1-118, and H1-119, this is thought to enhance charge carrier and exciton separation and minimize concentration quenching and polaron-exciton interactions. The triplet energy (2.80 eV) of compound H1-1 is higher than the triplet energy (2.4 eV) of G1, and does not cause quenching of light emission.

[Compound H1 as Host and EBL-Exemplary Devices # 4 to # 8]
Exemplary devices # 4, # 5, # 6, # 7, and # 8 had the structure 300 shown in FIG. EMLs of exemplary devices # 4, # 5, # 6, # 7, and # 8 are a hole transport compound (15% by mass) having the general formula H1 as the first host compound, and a compound as the second host compound It had a four-component composition consisting of H (60% by mass), compound E1 (20% by mass) as a third host compound, and phosphor dopant compound G1 (5% by mass).

The measured CIE 1931 coordinates, λ _max , and FWHM (full width at half maximum) of the emission spectrum from the example device are shown in Table 3. Example devices # 1 to # 8 with compound H1-1, H1-119, or H1-118 as a component in EML have better color saturation compared to reference device CE for comparison showed that. As shown in Table 3, two groups of exemplary devices were evaluated: (1) A first using the hole transport compound disclosed herein as one of the host compounds in the light-emitting layer with NPD as EBL. And (2) a second group using the compounds disclosed herein as one of the host compounds in the light-emitting layer and further as an EBL (Exemplary devices # 1 and # 2) 5, # 6, # 8, # 9, and # 14). The indenocarbazole derivative compound represented by the general formula H1 was used as a host together with a matrix host, H, an electron transport host, E1, and provided a hole transport host function. The comparative example device CE had only two host compounds, matrix host H, electron transport host E1, and NPD as EBL. Excellent saturation was achieved with all exemplary devices. The example device exhibited a narrower FWHM than the comparative device. The inventor believes that this may be evidence of an increased microcavity effect caused by the addition of a hole transport host to the EML. This suggests that in addition to the transport function of compound H1, its refractive index improves the reflection properties in EML, which narrows the emission spectrum and results in increased emission intensity. Let's go. These beneficial effects are not predictable because such effects are generally not predictable based on the chemical structure of the compound.

  The HOMO, LUMO levels, and triplet energy levels are shown in Table 1 above. The very shallow LUMO levels of compounds H1-1, H1-118, and H1-119 (2.10, 2.20, and 2.33 eV, respectively) prevent electrons from leaking into the HTL, and compounds H1-1, The high triplet energies of H1-118 and H1-119 (2.80, 2.79, and 2.77 eV, respectively) prevent excitons from leaking into the HTL. Excitons and electrons in a device using a compound such as H1-1, H1-118, or H1-119 as an exciton / electron blocking layer are better confined in the light emitting layer. Thus, it combines both charge-exciton separation in the emissive layer and electron and exciton block in the exciton / electron blocking layer.

All organic layers were deposited under high vacuum conditions (1 × 10 ⁻⁷ Torr). The PHOLED was transferred directly from the vacuum to a glove box with an inert atmosphere and sealed in the glove box using a UV curable epoxy and glass lid with a moisture absorber.

  Unless otherwise specified, any of the layers of the various aspects of the invention described herein can be deposited in any suitable manner. For organic layers, preferred methods include thermal evaporation, ink jet (eg, those of US Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entirety), organic vapor deposition (OVPD) (eg, Forrest Incorporated by reference in their entirety, such as those described in US Pat. No. 6,337,102, and organic vapor jet printing (OVJP) (eg, as described in US patent application Ser. No. 10 / 233,470). Which are incorporated by reference in their entirety). Other suitable deposition methods include spin coating and other solution processing methods. The solution based process is preferably carried out under nitrogen or an inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (such as those described in US Pat. Nos. 6,294,398 and 6,468,819), and a number of such as ink jet and OVJD. Patterning methods associated with such deposition methods are included. Other methods can also be used. The deposited materials may be modified to make them compatible with specific deposition methods. For example, substituents such as branched and unbranched and preferably alkyl and aryl groups containing at least 3 carbons may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 or more carbons may be used, and 3-20 carbons is a preferred range. A material with an asymmetric structure has better solution processability than one with a symmetric structure, because an asymmetric material can have a smaller tendency to recrystallization. Dendrimer substituents may be used to increase the ability of small molecules to undergo solution processability.

  The structures described herein are merely examples, and an OLED according to the disclosed invention is not limited to that specific structure, and can include more or fewer layers, or other combinations of layers.

Claims (28)

The anode, cathode, and a plurality of organic layers disposed therebetween, the plurality of organic layers, the light-emitting layer containing a host material and a phosphorescent material A including the organic light emitting device, wherein the host material ,
A first host compound ;
A second host compound ; and
Including a third host compound ,
Have a indeno carbazole ring structure wherein the first host compound is represented by the following general formula (H1):

Wherein A is a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of a substituted or unsubstituted condensed polycyclic aromatic Represents a group of
Ar ₁ , Ar ₂ , and Ar ₃ are the same or different and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group, Well, A and Ar ₂ , or Ar ₂ and Ar ₃ may be bonded to each other through a single bond, or through a substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring;
R _{1 to} R ₉ are the same or different and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, cyano, nitro, a linear or branched chain of 1 to 6 carbon atoms which may have a substituent Alkyl, optionally substituted cycloalkyl of 5 to 10 carbon atoms, optionally substituted straight chain or branched alkenyl of 2 to 6 carbon atoms, substituted Linear or branched alkyloxy of 1 to 6 carbon atoms optionally substituted, cycloalkyloxy of 5 to 10 carbon atoms optionally substituted, substituted or unsubstituted aromatic hydrocarbon It may be a group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy, which is a single bond, substituted or unsubstituted methylene, oxygen atom Or bonded to each other through a sulfur atom to form a ring Even if the well;
R ₁₀ and R ₁₁ are the same or different and may have a linear or branched alkyl of 1 to 6 carbon atoms which may have a substituent, or 5 to 10 carbon atoms which may have a substituent. A cycloalkyl, an optionally substituted linear or branched alkenyl of 2 to 6 carbon atoms, an optionally substituted linear or branched chain of 1 to 6 carbon atoms Alkyloxy, optionally substituted cycloalkyloxy having 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted Fused polycyclic aromatic groups, or substituted or unsubstituted aryloxy, which are bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. Also good. );
The second host compound is a compound represented by the following formula (H-IV), (HV), or (H-VI):

Wherein X is S or O;
R ₁ , R ₂ , and R ₃ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and non-condensed substitution independently selected from the group consisting of hydrogen A group;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
p is 1, 2, 3, or 4;
At least one of R ₁ , R ₂ , and R ₃ contains a triphenylene group. );

Wherein X is S or O;
R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH═CH—C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and a non-condensed substituent independently selected from the group consisting of hydrogen;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
o is 1, 2, 3, or 4; p is 1 or 2;
At least one of R ₁ and R ₂ contains a triphenylene group. );

Wherein X is S or O;
R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH═CH—C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and a non-condensed substituent independently selected from the group consisting of hydrogen;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
o and p are 1, 2, 3, or 4;
At least one of R ₁ and R ₂ contains a triphenylene group. ;; and
The third host compound is a compound different from the first host compound and the second host compound, and includes the following groups in the molecule:

Wherein X ^{1 to} X ⁸ are selected from C or N; Z ¹ and Z ² are S or O
, C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , and C _n H _2n -Ar ₁ (where n is 1, 2, 3, 4, 5, 6, 7 , 8, 9, or 10, wherein Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs) A compound that is substituted or unsubstituted with a non-condensable substituent selected from
Organic light emitting device. The organic light emitting device according to claim 1, wherein the first host compound is 25% by mass or less of the light emitting layer. The organic light emitting device according to claim 1, wherein the first host compound is 10 to 20% by mass of the light emitting layer. The organic light emitting device of claim 1, wherein the first host compound is selected from the group consisting of:

The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by a structure of formula (H-IV), wherein X is S. The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by the structure of formula (H-IV), wherein X is O. The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by a structure of formula (HV), wherein X is S. The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by a structure of formula (HV), wherein X is O. The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by the structure of formula (H-VI), wherein X is S. The organic light-emitting device according to claim 1 , wherein the second host compound is a compound represented by the structure of formula (H-VI), wherein X is O. The organic light emitting device of claim 1 , wherein the second host compound has the formula H

Before Symbol third host compound,

The organic light-emitting device according to claim 11 , wherein The organic light-emitting device according to any one of claims 1 to 12 , wherein the phosphorescent material is an organometallic compound selected from the group consisting of a phosphorescent organometallic platinum compound, an organometallic iridium compound, and an organometallic osmium compound. . The organic light-emitting device according to claim 13 , wherein the phosphorescent organometallic platinum compound has an aromatic ligand. The organic light-emitting device according to claim 13 , wherein the phosphorescent organometallic iridium compound has an aromatic ligand. The organic light-emitting device according to claim 13 , wherein the phosphorescent organometallic osmium compound has an aromatic ligand. An anode, a cathode, and a plurality of organic layers disposed therebetween, wherein the plurality of organic layers are disposed between a light emitting layer including a host material and a phosphorescent material, and between the light emitting layer and the anode. An organic device comprising an exciton / electron blocking layer,
The host material of the light emitting layer is
A first host compound ;
A second host compound ; and
Including a third host compound ,
Have a indeno carbazole ring structure wherein the first host compound is represented by the following general formula (H1):

Wherein A is a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of a substituted or unsubstituted condensed polycyclic aromatic Represents a group of
Ar ₁ , Ar ₂ , and Ar ₃ are the same or different and are a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group, Well, A and Ar ₂ , or Ar ₂ and Ar ₃ may be bonded to each other through a single bond, or through a substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring;
R _{1 to} R ₉ are the same or different and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, cyano, nitro, a linear or branched chain of 1 to 6 carbon atoms which may have a substituent Alkyl, optionally substituted cycloalkyl of 5 to 10 carbon atoms, optionally substituted straight chain or branched alkenyl of 2 to 6 carbon atoms, substituted Linear or branched alkyloxy of 1 to 6 carbon atoms optionally substituted, cycloalkyloxy of 5 to 10 carbon atoms optionally substituted, substituted or unsubstituted aromatic hydrocarbon It may be a group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy, which is a single bond, substituted or unsubstituted methylene, oxygen atom Or bonded to each other through a sulfur atom to form a ring Even if the well;
R ₁₀ and R ₁₁ are the same or different and may have a linear or branched alkyl of 1 to 6 carbon atoms which may have a substituent, or 5 to 10 carbon atoms which may have a substituent. A cycloalkyl, an optionally substituted linear or branched alkenyl of 2 to 6 carbon atoms, an optionally substituted linear or branched chain of 1 to 6 carbon atoms Alkyloxy, optionally substituted cycloalkyloxy having 5 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted Fused polycyclic aromatic groups, or substituted or unsubstituted aryloxy, which are bonded to each other through a single bond, substituted or unsubstituted methylene, oxygen atom, or sulfur atom to form a ring. Also good. );
The second host compound is a compound represented by the following formula (H-IV), (HV), or (H-VI):

Wherein X is S or O;
R ₁ , R ₂ , and R ₃ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and non-condensed substitution independently selected from the group consisting of hydrogen A group;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
p is 1, 2, 3, or 4;
At least one of R ₁ , R ₂ , and R ₃ contains a triphenylene group. );

Wherein X is S or O;
R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH═CH—C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and a non-condensed substituent independently selected from the group consisting of hydrogen;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
o is 1, 2, 3, or 4; p is 1 or 2;
At least one of R ₁ and R ₂ contains a triphenylene group. );

Wherein X is S or O;
R ₁ and R ₂ are C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH═CH—C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , C _n H _2n -Ar ₁ , and a non-condensed substituent independently selected from the group consisting of hydrogen;
n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs;
o and p are 1, 2, 3, or 4;
At least one of R ₁ and R ₂ contains a triphenylene group. ;; and
The third host compound is a compound different from the first host compound and the second host compound, and includes the following groups in the molecule:

Wherein X ^{1 to} X ⁸ are selected from C or N; Z ¹ and Z ² are S or O
, C _n H _{2n + 1} , OC _n H _{2n + 1} , OAr ₁ , N (C _n H _{2n + 1} ) ₂ , N (Ar ₁ ) (Ar ₂ ), CH = CH-C _n H _{2n + 1} , C = CHC _n H _{2n + 1} , Ar ₁ , Ar ₁ -Ar ₂ , and C _n H _2n -Ar ₁ (where n is 1, 2, 3, 4, 5, 6, 7 , 8, 9, or 10, wherein Ar ₁ and Ar ₂ are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs) A compound that is substituted or unsubstituted with a non-condensable substituent selected from: and
The exciton / electron blocking layer includes a blocking compound having an indenocarbazole ring structure represented by the general formula H1, and the exciton / electron blocking layer blocks at least one of excitons and electrons;
An organic light emitting device wherein the first host compound and the blocking compound are the same or different. 18. The organic light emitting device of claim 17 , wherein the first host compound and the blocking compound are independently selected from the group consisting of:

Before Symbol third host compound,

The organic light-emitting device according to claim 17 , wherein The organic light emitting device of claim 17 , wherein the exciton / electron blocking layer blocks both excitons and electrons. The organic light-emitting device according to claim 17 , wherein the phosphorescent material is an organometallic compound selected from the group consisting of a phosphorescent organometallic platinum compound, an organometallic iridium compound, and an organometallic osmium compound. The organic light-emitting device according to claim 21 , wherein the phosphorescent organometallic platinum compound has an aromatic ligand. The organic light-emitting device according to claim 21 , wherein the phosphorescent organometallic iridium compound has an aromatic ligand. The organic light-emitting device according to claim 21 , wherein the phosphorescent organometallic osmium compound has an aromatic ligand. An organic light emitting device comprising an anode, a cathode, and a plurality of organic layers disposed therebetween, the plurality of organic layers comprising a light emitting layer comprising a host material and a phosphorescent material,
The host material includes a first host compound and a second host compound, and the first host compound is

The second host compound is selected from the group consisting of:

Represented by:
The phosphorescent material is represented by the following formula G1:

An organic light-emitting device, which is a compound represented by: The light emitting layer further includes a third host compound, and the third host compound is represented by the following formula E1:

The organic light-emitting device according to claim 25, which is a compound represented by the formula: The organic light-emitting device according to claim 25 , wherein the first host compound is 25% by mass or less of the light-emitting layer. The organic light-emitting device according to claim 25 , wherein the first host compound is 10 to 20% by mass of the light-emitting layer.

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