Organic electroluminescent materials and devices

Abstract

To provide an organometallic complex used as a light emitter.SOLUTION: There are provided an organometallic complex where a molecule of a compound has an orientation factor greater than 0.67, and devices, such as organic light emitting diodes, including the organometallic complex.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application claims priority under 35 U.S.C. § 119(e)(1) to U.S. Provisional Application No. 15 / 239,961, filed Aug. 18, 2016; U.S. Provisional Application No. 62 / 330,412, filed May 2, 2016; U.S. Provisional Application No. 62 / 322,510, filed Apr. 14, 2016; U.S. Provisional Application No. 62 / 291,960, filed Feb. 5, 2016; U.S. Provisional Application No. 62 / 232,194, filed Sep. 24, 2015; and U.S. Provisional Application No. 62 / 213,757, filed Sep. 3, 2015, the entire disclosures of each of which are hereby incorporated by reference.

[0002] Cross - Reference to Related Applications The claimed invention has been made, in part or in whole, by one or more of the directors of the following parties to a university - industry research agreement: University of Michigan, Princeton University, University of Southern California, and Universal Display Corporation, and is made, at least in part, in the interests of and / or in connection with such parties. The agreement was in effect prior to the date the claimed invention was made, and the claimed invention was made as a result of activities within the scope of the agreement.

[0003] The present invention relates to compounds used as emitters and devices such as organic light - emitting diodes containing such compounds.

Background Art

[0004] Optoelectronic devices using organic materials are becoming increasingly desirable for several reasons. Many of the materials used to fabricate such devices are relatively inexpensive, so organic optoelectronic devices have the potential for cost advantages over inorganic devices. In addition, due to the inherent properties of organic materials such as flexibility, the material can be well-suited for specific applications such as fabrication on flexible substrates. Examples of organic optoelectronic devices include organic light-emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials can have performance advantages over conventional materials. For example, the wavelength at which the organic light-emitting layer emits light can generally be easily adjusted with appropriate dopants.

[0005] OLEDs utilize thin organic films that emit light when a voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, lighting, and backlighting. Several OLED materials and configurations are described in Patent Documents 1, 2, and 3, which are hereby incorporated by reference in their entirety.

[0006] One use of phosphorescent emitting molecules is in full-color displays. The industry standard for such displays requires pixels that are adapted to emit specific colors referred to as "saturated" colors. In particular, these standards require saturated red, green, and blue pixels. Alternatively, OLEDs can be designed to emit white light. Conventional liquid crystal display emission from white backlights is filtered using absorption filters to produce red, green, and blue emission. Similar techniques can also be used with OLEDs. White OLEDs can be either a single EML device or a stacked structure. Color can be measured using CIE coordinates well-known in the art.

[0007] An example of a green-emitting molecule has the following structure:

Chemical formula

[0008] In this drawing and the subsequent drawings in this specification, the inventors depict the coordination bond from nitrogen to metal (here Ir) as a straight line.

[0009] As used herein, the term "organic" includes polymeric materials and small molecule organic materials that can be used to fabricate organic optoelectronic devices. "Small molecule" refers to any organic material that is not a polymer, and a "small molecule" can actually be quite large. A small molecule can include repeating units in some situations. For example, using a long-chain alkyl group as a substituent does not exclude a molecule from the "small molecule" class. A small molecule may be incorporated into a polymer, for example, as a pendant group on a polymer backbone or as part of the backbone. A small molecule can also serve as the core portion of a dendrimer consisting of a series of chemical shells constructed on the core portion. The core portion of the dendrimer can be a fluorescent or phosphorescent small molecule emitter. A dendrimer can be a "small molecule", and it is considered that all dendrimers currently used in the field of OLEDs are small molecules.

[0010] As used herein, "top" means the farthest part from the substrate, while "bottom" means the nearest part to the substrate. When the first layer is described as being "disposed on" the second layer, the first layer is disposed farther from the substrate. Unless it is specified that the first layer is "in contact with" the second layer, there may be other layers between the first layer and the second layer. For example, even if there are various organic layers in between, the cathode can be described as being "disposed on" the anode.

[0011] As used herein, "solution processable" means capable of being dissolved, dispersed, or transported in a liquid medium in either solution or suspension form and / or capable of being deposited from the medium.

[0012] A ligand can be termed "photoactive" if it is considered to directly contribute to the photoactive properties of the luminescent material. A ligand can be termed "auxiliary" if it is considered not to contribute to the photoactive properties of the luminescent material, although an auxiliary ligand can modify the properties of the photoactive ligand.

[0013] As used herein, as would be generally understood by one of ordinary skill in the art, the first "highest occupied molecular orbital" (HOMO) or "lowest unoccupied molecular orbital" (LUMO) energy level is "greater" or "higher" than the second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since the ionization potential (IP) is measured as a negative energy relative to the vacuum level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (less negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (less negative EA). In a conventional energy level diagram with the vacuum level at the 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 to be closer to the top of such a diagram than a "lower" HOMO or LUMO energy level.

[0014] As used herein, as would be generally understood by one of ordinary skill in the art, if the first work function has a higher absolute value, the first work function is "greater" or "higher" than the second work function. Since the work function is generally measured as a negative number relative to the vacuum level, this means that a "higher" work function is more negative. In a conventional energy level diagram with the vacuum level at the top, a "higher" work function is illustrated as being further away in the downward direction from the vacuum level. Thus, the definitions of the HOMO and LUMO energy levels follow a different convention than the work function.

[0015] Further details regarding OLEDs and the definitions described above can be found in Patent Document 4, which is hereby incorporated by reference in its entirety.

[0016] According to an embodiment, a compound represented by the formula M(L A ) h (L B ) y (L C ) z is provided, wherein the ligands L A , L B , and L C are each independently selected from the group consisting of the following:

Chemical formula

Chemical formula

[0017] According to another embodiment, a compound represented by a structure selected from the group consisting of the following formula (L A ) m Ir(L B ) 3-m is disclosed.

Chemical formula

[0018] According to another embodiment, an organic light emitting diode / device (OLED) is also disclosed. The OLED can include an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer can

Chemical formula

Chemical formula

Chemical formula

[0019] According to yet another embodiment, a composition is disclosed, the composition comprising

Chemical Formula

Chemical formula

Chemical formula

Brief Description of the Drawings

[0020]

Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

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Figure 8

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Figure 9

[0029]

Figure 10

Mode for Carrying Out the Invention

[0030] Generally, an OLED includes at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons move to the oppositely charged electrodes, respectively. When an electron and a hole are localized on the same molecule, an "exciton", which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted via a photoelectron emission mechanism when the exciton relaxes. In some cases, the exciton can be localized on an excimer or an exciplex. Although non-radiative mechanisms such as thermal relaxation may occur, they are generally considered undesirable.

[0031] Initial OLEDs used luminescent molecules ("fluorescence") that emit light from their singlet state, as disclosed, for example, in U.S. Patent No. 4,769,292, which is incorporated herein by reference in its entirety. Fluorescent emission generally occurs within a time frame of less than 10 nanoseconds.

[0032] More recently, OLEDs having luminescent materials ("phosphorescence") that emit light from their triplet state have been demonstrated. Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices", 395, 151 - 154, 1998; ("Baldo-I") and Baldo et al., "Very high-efficiency green organic light emitting devices based on electrophosphorescence", Appl. Phys. Lett., 75, No. 3, 4 - 6 (1999) ("Baldo-II"), which are incorporated herein by reference in their entirety. Phosphorescence is described in more detail in U.S. Patent No. 7,279,704, columns 5 - 6, which is incorporated herein by reference.

[0033] FIG. 1 shows an organic light emitting device 100. The figure is not necessarily to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, a light emitting layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a barrier layer 170. Cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 may be fabricated by sequentially depositing the described layers. The characteristics, functions, and material examples of these various layers are described in further detail in U.S. Patent No. 7,279,704, incorporated by reference, in paragraphs 6-10.

[0034] For each of these layers, further examples are available. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, incorporated by reference in its entirety, of m-MTDATA to F in a molar ratio of 50:1 4- It is doped with TCNQ. Examples of luminescent materials and host materials are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated herein by reference in its entirety. An example of an n-doped electron transport layer is one doped with Li in a 1:1 molar ratio to BPhen as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entirety, disclose examples of cathodes including a composite cathode having a thin layer of a metal such as Mg:Ag with a transparent, conductive, sputter-deposited ITO layer covering the top. The theory and use of blocking layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated herein by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety. A description of the protective layer can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety.

[0035] Figure 2 shows an inverted OLED 200. The device includes a substrate 210, a cathode 215, a light-emitting layer 220, a hole transport layer 225, and an anode 230. The device 200 can be fabricated by depositing the described layers in sequence. The most common OLED configuration has a cathode disposed on top of the anode, and since the device 200 has a cathode 215 disposed under the anode 230, the device 200 may be referred to as an "inverted" OLED. Materials similar to those described for the device 100 may be used in the corresponding layers of the device 200. Figure 2 provides an example of how some layers can be omitted from the structure of the device 100.

[0036] The simple layer structures illustrated in FIGS. 1 and 2 are provided as non-limiting examples, and it is understood that embodiments of the present invention can be used in connection with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs can be realized by combining the various layers described in various ways, or the layers can be omitted entirely based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Many of the examples provided herein describe the various layers as including a single material, but it is understood that combinations of materials such as mixtures of hosts and dopants, or more generally mixtures, may be used. Also, the layers may have various sub-layers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into light-emitting layer 220 and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an "organic layer" disposed between a cathode and an anode. The organic layer may include a single layer or may further include multiple layers of different organic materials as described, for example, with respect to FIGS. 1 and 2.

[0037] OLEDs (PLEDs) and the like composed of polymer materials such as those disclosed in Friend et al.'s U.S. Patent No. 5,247,190, which is incorporated by reference in its entirety, may be used with structures and materials not specifically described. As a further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example, as described in Forrest et al.'s U.S. Patent No. 5,707,745, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layer structures illustrated in FIGS. 1 and 2. For example, the substrate may include angled reflective surfaces for improving outcoupling, such as mesa structures as described in Forrest et al.'s U.S. Patent No. 6,091,195, which is incorporated by reference in its entirety, and / or indentation structures as described in Bulovic et al.'s U.S. Patent No. 5,834,893, which is incorporated by reference in its entirety.

[0038] Unless otherwise specified, any of the layers of the various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation such as those described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated herein by reference in their entirety, inkjet, organic vapor deposition (OVPD) such as those described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated herein by reference in its entirety, and deposition by organic vapor jet printing (OVJP) such as those described in U.S. Pat. No. 7,431,968, which is incorporated herein by reference in its entirety. Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably carried out in a nitrogen or inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include masking such as those described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated herein by reference in their entirety, deposition via cold welding, and patterning associated with some of the deposition methods such as inkjet and OVJP. Other methods may be used. The materials to be deposited can be modified to be compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups that are branched or unbranched and preferably contain at least 3 carbons can be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 or more carbons can be used, with 3 to 20 carbons being a preferred range. Materials having an asymmetric structure can have better solution processability than those having a symmetric structure, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents can be used to enhance the ability of small molecules to undergo solution processing.

[0039] Devices fabricated in accordance with embodiments of the present invention may further include a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in an environment containing moisture, vapor and / or gas, etc. The barrier layer may be deposited on the substrate, above, below or adjacent to the electrodes, or on any other part of the device including the edges. The barrier layer may include a single layer or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase and compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate inorganic or organic compounds or both. Preferred barrier layers include mixtures of polymeric and non-polymeric materials as described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are hereby incorporated by reference in their entirety. For a mixture to be considered a "mixture", the polymeric and non-polymeric materials constituting the barrier layer should be deposited under the same reaction conditions and / or simultaneously. The weight ratio of the polymeric material to the non-polymeric material can range from 95:5 to 5:95. The polymeric material and the non-polymeric material can be made from the same precursor material. In one example, the mixture of the polymeric material and the non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

[0040] Devices fabricated in accordance with embodiments of the present invention can be incorporated into a wide variety of electronic component modules (or units) that can be incorporated into various electrical products or intermediate components. Such electrical products or intermediate components include display screens, lighting devices (such as discrete light source devices or lighting panels, etc.) that can be utilized by end-user product manufacturers. Such electronic component modules can optionally include drive electronics and / or power supplies. Devices fabricated in accordance with embodiments of the present invention can be incorporated into a wide variety of consumer products having one or more incorporated electronic component modules (or units). Such consumer products include any type of product that includes one or more light sources and / or one or more certain types of display devices. Some examples of such consumer products include flat panel displays, computer monitors, medical monitors, televisions, bulletin boards, indoor or outdoor lighting and / or lights for signal transmission, head-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, mobile phones, tablets, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, camcorders, viewfinders, microdisplays, 3-D displays, vehicles, large area walls, theater or stadium screens, or billboards. Various control mechanisms, including passive matrix and active matrix, can be used to control devices fabricated in accordance with the present invention. Many of the devices are intended for use within a temperature range comfortable for humans, such as from 18 degrees Celsius to 30 degrees Celsius, more preferably room temperature (20 to 25 degrees Celsius), but can also be used outside of this temperature range, for example, from -40 degrees Celsius to +80 degrees Celsius.

[0041] The materials and structures described herein can have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can utilize the materials and structures. More generally, organic devices such as organic transistors can utilize the materials and structures.

[0042] As used herein, the terms "halo", "halogen", or "halide" include fluorine, chlorine, bromine, and iodine.

[0043] As used herein, the term "alkyl" means both straight-chain and branched-chain alkyl groups. Preferred alkyl groups include those containing from 1 to 15 carbon atoms, such as methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, and 2,2-dimethylpropyl. Further, the alkyl group may be substituted.

[0044] As used herein, the term "cycloalkyl" means a cyclic alkyl group. Preferred cycloalkyl groups include those containing 3 to 10 ring carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, and adamantyl. Further, the cycloalkyl group may be substituted.

[0045] As used herein, the term "alkenyl" means both straight-chain and branched-chain alkenyl groups. Preferred alkenyl groups are alkenyl groups containing 2 to 15 carbon atoms. Further, the alkenyl group may be substituted.

[0046] As used herein, the term "alkynyl" means both straight-chain and branched-chain alkynyl groups. Preferred alkynyl groups are alkynyl groups containing 2 to 15 carbon atoms. Further, the alkynyl group may be substituted.

[0047] As used herein, the terms "aralkyl" or "arylalkyl" are used interchangeably and mean an alkyl group having an aromatic group as a substituent. Further, the aralkyl group may be substituted.

[0048] As used herein, the term "heterocyclic group" means an aromatic ring group and a non-aromatic ring group. A heteroaromatic ring group also means heteroaryl. Preferred hetero non-aromatic ring groups are at least one heteroatom containing 3 to 7 ring atoms, including cyclic amines such as morpholino, piperidino, pyrrolidino, etc., and including cyclic ethers such as tetrahydrofuran, tetrahydropyran, etc. Further, the heterocyclic group may be substituted.

[0049] As used herein, the term "aryl" or "aromatic group" means a monocyclic and polycyclic system. Polycyclic means having two or more rings in which two carbons are shared by two adjacent rings (the rings are "fused"), and at least one of the rings is aromatic, for example, the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocycle, and / or heteroaryl. Preferred aryl groups contain 6 to 30 carbon atoms, preferably those containing 6 to 20 carbon atoms, and more preferably those containing 6 to 12 carbon atoms. Aryl groups having 6 carbons, 10 carbons, or 12 carbons are particularly preferred. Suitable aryl groups include phenyl, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene, etc., and phenyl, biphenyl, triphenyl, triphenylene, fluorene, and naphthalene are preferred. Further, the aryl group may be substituted.

[0050] As used herein, the term "heteroaryl" means a monocyclic heteroaromatic group that can contain from 1 to 5 heteroatoms. The term heteroaryl also includes polycyclic heteroaromatic systems having two or more rings in which two atoms are shared by two adjacent rings (the rings are "fused"), at least one of the rings being heteroaryl, and for example, the other rings can be cycloalkyl, cycloalkenyl, aryl, heterocycle, and / or heteroaryl. Preferred heteroaryl groups are those containing from 3 to 30 carbon atoms, more preferably those containing from 3 to 20 carbon atoms, and even more preferably those containing from 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine, and dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazine, and their aza analogs are preferred. Further, the heteroaryl group may be substituted.

[0051] The alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocycle, aryl, and heteroaryl are unsubstituted or may be substituted with one or more substituents selected from deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0052] As used herein, "substituted" indicates that a substituent other than H is bonded to a relevant position such as carbon. Thus, for example, when R 1 is monosubstituted, R 1 must be other than H. Similarly, when R 1 is disubstituted, two of R 1 must be other than H. Similarly, when R 1 is unsubstituted, R 1 is hydrogen at all substitution positions.

[0053] As used herein, the term "aza" in fragments described herein, such as aza-dibenzofuran, aza-dibenzothiophene, etc., means that one or more of the C-H groups in each fragment can be replaced by a nitrogen atom. For example, but not by way of limitation, azatriphenylene encompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. One of ordinary skill in the art can readily envision other nitrogen analogs of the above-described aza derivatives, and it is intended that all such analogs are encompassed by the terms described herein.

[0054] It should be understood that when a molecular fragment is described as a substituent or as being attached to another moiety, its name may be described as a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuryl) or the entire molecule (benzene, naphthalene, dibenzofuran). In this specification, these are considered equivalent even if the way of representing substituents or linking fragments is different.

[0055] Iridium complexes containing simple alkyl-substituted phenylpyridine ligands are widely used as emitters in phosphorescent OLEDs. In some embodiments, the present disclosure discloses iridium complexes containing substituted phenylpyridine ligands having a specific substitution pattern or specific novel substitutions that form bulky groups on the Ir complex. Also, the bulky groups on the Pt complex ligands exhibit higher EQE and lower excimer formation. These substitutions unexpectedly improve device efficiency and lifetime. These substitutions also orient the metal complex such that the transition dipole moment of the metal complex is parallel to the OLED substrate to increase the external quantum efficiency of the emitter. The parallel orientation of the transition dipole moment of the emitter metal complex increases the amount of light extracted from the OLED. This is because the emission is perpendicular to the transition dipole of the emitter compound.

[0056] Determination of the Orientation of the Emitter Transition Dipole Moment The orientation of the transition dipole moment of the emitter in an OLED has been of great interest as one of the important factors limiting the external quantum efficiency. Many different methods for measuring the orientation have been used and reported in recent literature. The reported methods include angular profile measurement followed by optical simulation; integrating sphere EQE measurement of EL devices with or without outcoupling lenses using devices with different ETL thicknesses; and single-color electro-luminescence far-field angle pattern measurement. All of these methods use commercially available optical simulation software for data calculation and data interpretation.

[0057] The following method was designed to evaluate the orientation factors of a number of OLED emitters used in devices with standard material combinations. Typically, the materials of interest were used in devices with structures optimized for maximum efficiency. To increase the sensitivity of the measured emission to emitter dipole orientation, this method requires a modified structure in which the layer thicknesses are varied.

[0058] Selection of Device Structure An important factor in verifying the dipole orientation of OLED emitters is to adjust the structure of the sample device to increase the emission optical characteristics that are most sensitive to dipole orientation. In a bottom-emission device, when adjusted to the maximum wavelength of the emission spectrum to obtain a cavity effect, the distance from the emitter position to the reflective cathode becomes the dominant parameter. The cavity effect thus activated is most readily seen in the angular measurement of polarized emission.

[0059] The structure needs to have a matrix for holding the emitter at a clearly defined position and a method for activating the electroluminescence of the emitter. The structure constitutes a complex optical system with a number of interfaces and includes materials with various optical properties, but can be designed by providing a distance between the emission site and the reflective cathode (a major factor determining the far-field pattern in air).

[0060] Table 1 An example of a device structure devised to determine the orientation factor of a yellow emitter [Table 1] Table 2 An example of a device structure devised to determine the orientation factor of a green emitter [Table 2] * Carrier blocking layer that confines the light source in a thin EML ** A thick ETL that resonates with yellow or green emission, together with a part of the HBL and EML ***A thin 100 Å EML that confines the recombination region (RZ) to a narrow area

[0061] Table 1 shows examples of device structures that can be used to determine the orientation factor of a yellow emitter compound. The layer thicknesses shown in Table 1 are designed for measuring the yellow emitter orientation factor. Examples of device structures for determining the orientation factor of a green emitter are shown in Table 2. The layer thickness can be adjusted according to its emission wavelength for red, green, or blue. Usually, by adjusting the appropriate layer thickness, the distance between the RZ, the reflective electrode, and the transparent electrode in the EML is adjusted, and the light output is maximized by the constructive interference between the light emitted from the RZ and the light reflected from the reflective electrode. The distance is adjusted by the layer thickness of the device and is proportional to the emission wavelength. The organic emitter is included in a 100 Å thick EML. The emission of the organic emitter is usually (but not exactly) monochromatic. Each part of the spectrum interacts with the light reflected by the cathode in different ways, changing the original spectrum. Therefore, the spectrum observed by the far-field device may be different from the original PL spectrum of the emitter.

[0062] Examples of the materials of various components in the exemplary device structures for determining the yellow and green emitter orientation factors are as follows. · Anode: ITO; · HIL: HATCN; · HTL: as follows

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0063] test Illuminant Example 2 in Table 3 (Comp(L A147 ) 2 Ir(L B184 The procedure for determining the orientation factor of ) is described below. Spectral measurements of the device structures in Table 1 are performed using a calibrated spectrophotometer model PR740. Since this instrument uses an image of a dot projected onto a shutter with a small aperture, small parallax effects are expected when the object is viewed at an angle. This needs to be corrected by using simple geometry. At angles greater than 50°, additional effects of the instrument occur when viewing the reflection of light from the back glass cover of the device. For this reason, data obtained at angles wider than 50° are used only for trending purposes, and calculations are based only on data obtained at angles between 30 and 50°. In the majority of samples, the effect analyzed at an angle of 40° is strong enough to give reliable data, and therefore data obtained at angles wider than this do not need to be quantified.

[0064] The comparison between the measured spectral data and the simulated spectral data is the most accurate measurement for knowing the degree of agreement between the simulation data and the actual emission. Since the simulation software methodology is based on the optical characteristics of the light source, the agreement between the observed data and the simulation data verifies the effectiveness of using the simulation to calibrate the emitter performance for the calculated dipole orientation. The ratio of the p-radiance to the s-radiance measured in the range of 30 to 50° is strongly correlated with the orientation factor. By using the p / s radiance ratio, potential problems related to the absolute calibration of the radiance measurement due to the imperfection of the optical system are eliminated.

[0065] Spectrum Figure 3 shows the EL spectrum of the device of emitter Example 2 in the structure shown in Table 1, obtained at various angles from 0 to 60° through an s-polarizer. Figure 4 is the angle-dependent s-EL spectrum of the same device structure simulated using the Fluxim program SETFOS-4.1. The experimental spectrum and the simulation spectrum are in agreement.

[0066] Results and Interpretation Details of the dependence of the estimated dipole orientation number on the angular data in a given spectrum and device structure will be described below. The graph in Fig. 5 is based on data generated by simulation software and a spectrum that matched as shown in Figs. 3 and 4 for a sample having the structure shown in Table 1. In this specific example, the integrated p / s radiance ratio at an angle of 40° is 1.67, and the corresponding dipole orientation (DO) is 0.15 (Fig. 6). The number of DOs generated by the simulation software represents the statistical distribution of the vertical-to-horizontal orientation. The vertical and horizontal directions are directions with respect to the substrate, where vertical means a direction perpendicular to the substrate surface and horizontal means a direction parallel to the substrate surface. In the case of one vertical direction and two horizontal directions, the DO number scale is from 0 (parallel or horizontal) to 0.33 (isotropic). The corresponding scale of 1 to 0.67 represents the percentage of the original EQE after loss due to dipole orientation. This value defined as Θ = 1 - DO is called the emitter orientation factor (in the example of the present inventors, Θ = 1 - 0.15 = 0.85, i.e., 85% of the maximum EQE) and is also used in experimental data. This represents the % of emitter dipoles aligned parallel to the substrate. The graphs in Figs. 7 and 8 show that the angular response to dipole orientation at angles of 30° to 50° is much stronger for p-radiance than for s-radiance. Also, as the number of dipole orientations increases, the p-radiance value increases while the s-radiance decreases. The obtained p / s ratio shows a very high sensitivity to dipole orientation from the observation angle of 30°. In this measurement, since 40° gives the largest difference between s-emission and p-emission and the highest sensitivity, an angle of 40° is selected.

[0067] The material has a preferred orientation (the "orientation factor") having an anisotropic horizontal / vertical dipole ratio in a thin solid film, i.e., the horizontal / vertical dipole ratio is greater than 0.67:0.33 (in the isotropic case) (for example, a ratio of 0.77:0.23). Stated in another way, the orientation factor Θ (the ratio of horizontal dipoles to all dipoles) is greater than 0.67.

[0068] Figure 9 shows the correlation obtained between the estimated maximum EQE and the orientation factor. An obvious increase in EQE is observed as the orientation factor increases. The closer the orientation factor is to 1, the more parallel the emitter molecules are arranged with respect to the substrate, which is favorable for improved device efficiency.

[0069] The procedure for measuring the photoluminescence quantum efficiency (PLQY) of the emitter in PMMA is described here. General preparation and experiments for solid samples: Weigh PMMA and the emitter (various wt%) and dissolve them in toluene. Filter the resulting solution through a 2 - micron filter and drop - cast it onto a pre - cleaned quartz substrate. The PL quantum efficiency measurement was performed with a Hamamatsu C9920 system equipped with a xenon lamp, an integrating sphere, and a model C10027 photon - multi - channel analyzer. Table 3 Correlation of the estimated EQE in the device with the emitter PLQY and the orientation factor

Table 3

Table 4

[0070] Figure 10 shows the correlation of the emitter PLQY in the thin film as a function of the emitter concentration. Comp (L A1 ) 2 Ir (L B182For non-bulky emitters such as (0), as the emitter concentration increases beyond 10%, the PLQY decreases significantly. However, for bulkier emitters (e.g., the emitters used in Device Examples 2 and 9), the decrease in PLQY with increasing emitter concentration is not rapid. The steric bulk of the emitter molecules prevents self-quenching at high emitter %.

[0071] From the above-described emitter orientation and PLQY measurements, it can be seen that the bulkier the emitter is sterically in a certain direction on the molecule, the more parallel the orientation (with respect to the substrate of the OLED), and thus the higher the EQE in the device. Examples of these emitters are shown below, and they are those described in Tables 3 and 4.

Chemical formula

Chemical formula

[0072] According to some embodiments of the present disclosure, a compound represented by the formula M(L A ) h (L B ) y (L C ) z is disclosed, wherein the ligands L A , L B , and L C are each independently selected from the group consisting of the following.

Chemical formula

Chemical formula

[0073] In the formula M(L A ) h (L B ) y (L C ) zIn some embodiments of the compound represented by, M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu. In another embodiment, M is Ir or Pt.

[0074] In some embodiments, the molecule of the compound has an orientation factor Θ value of at least 0.75. In another embodiment, the molecule has an orientation factor value of at least 0.80. In another embodiment, the molecule has an orientation factor value of at least 0.85. In another embodiment, the molecule has an orientation factor value of at least 0.91. In another embodiment, the molecule has an orientation factor value of at least 0.92. In another embodiment, the molecule has an orientation factor value of at least 0.93. In another embodiment, the molecule has an orientation factor value of at least 0.94.

[0075] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z One of R a , R b , R c , and R d is monosubstituted with at least 13 carbon atoms, and the rest of R a , R b , R c , and R d all have a maximum carbon number of 6.

[0076] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z In some embodiments, X 1 to X 13 are each carbon.

[0077] In the formula M(L A ) h (LB ) y (L C ) z In some embodiments of the compound represented by, the compound has the formula Ir(L A ) 2 (L B ).

[0078] In some embodiments of the compound represented by the formula Ir(L A ) 2 (L B ), L A is represented by a formula selected from the group consisting of the following,

Chemical formula

Chemical formula

Chemical formula

[0079] In some embodiments of the compound represented by the formula Ir(L A ) 2 (L B ), L A and L B are different and are each independently selected from the group consisting of the following.

Chemical formula

Chemical formula

[0080] In some embodiments of the compound represented by the formula Ir(L A ) 2 (L B ), L A and L B are each independently selected from the group consisting of the following.

Chemical formula

Chemical formula

[0081] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z , the compound is represented by the formula Pt(L A )(L B ) (wherein L A and L B are different). In some embodiments of the compound, L A is combined with L B to form a tridentate ligand.

[0082] In the formula M(L A ) h (L B ) y (L C ) zIn some embodiments of the compound represented by , it is represented by formula (L) having a structure selected from the following group (Group 1): A ) m Ir(L B ) 3-m wherein, m is 1 or 2; R

Chemical formula

[0083] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z , the compound is represented by formula (L) having a structure selected from the following group: A ) m Ir(L B ) 3-m wherein, m is 1 or 2.

Chemical formula

[0084] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z in some embodiments, the compound is represented by the formula (L A ) m Ir(L B ) 3-m wherein m is 1 or 2; R 2 , R 3 , R 4 , and R 5 are each independently selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, and combinations thereof.

[0085] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z in some embodiments, the compound is represented by the formula (L A ) m Ir(L B ) 3-m wherein m is 1 or 2; R 6 is selected from the group consisting of alkyl having at least 8 carbon atoms, cycloalkyl having at least 8 carbon atoms, alkyl-cycloalkyl having at least 8 carbon atoms, and partially or fully deuterated or fluorinated variants thereof.

[0086] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z in some embodiments, the compound is represented by the formula (L A ) m Ir(L B ) 3-mrepresented by; m is 1 or 2; R 3 、R 4 、and R 5 are each hydrogen. In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z , the compound is of the formula (L A ) m Ir(L B ) 3-m represented by; m is 1 or 2; L A is selected from the group consisting of the following.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0087] In some embodiments of the compound represented by the formula M(L A ) h (L B ) y (L C ) z , the compound is represented by the formula (L A ) m Ir(L B ) 3-m ; m is 1 or 2; L B is selected from the group consisting of the following L B1 to L B227 .

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0088] represented by a structure selected from Group 1, where L A is L A1 ~L A225 one of, and the formula (L A ) m Ir(L B ) 3-m In some embodiments of the compound, the compound has the formula Ir(L Aj ) 2 (L Bk ) and is compound x, where x = 227j + k - 227, j is an integer from 1 to 225, and k is an integer from 1 to 227.

[0089] represented by a structure selected from Group 1, where L A is L A1 ~L A225 one of, and the formula (L A )Pt(L B ) In some embodiments of the compound, the compound has the formula Pt(L Aj )(L Bk ) and is compound y, where x = 227j + k - 227, j is an integer from 1 to 225, and k is an integer from 1 to 227. L B1 ~L B227 is as shown above.

[0090] According to another aspect of the present disclosure, a compound represented by the formula (L A ) m Ir(L B ) 3-m is disclosed, and the compound is represented by a structure selected from the following group (Group 2). [Chemical formula] In the formula, m is 1 or 2; R 1 , R 2 , R 4 , and R 5 each independently represents mono, di, tri, or tetra substitution, or no substitution; R 3 represents mono, di, or tri substitution, or no substitution; R 6 represents mono substitution, or no substitution; R 1 , R 2 , R 3 , R 4 , R 5 and R 6 each independently is selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, partially or fully deuterated or fluorinated variants thereof, and combinations thereof.

[0091] In some embodiments of the compound represented by the structure selected from Group 2, R 1 , R 2 , R 3 , R 4 , and R 5 each independently is selected from the group consisting of hydrogen, deuterium, C1-C6 alkyl, C1-C6 cycloalkyl, and partially or fully deuterated or fluorinated variants thereof; R 6 is selected from the group consisting of alkyl having at least 7 carbon atoms, cycloalkyl having at least 7 carbon atoms, alkyl-cycloalkyl having at least 7 carbon atoms, and partially or fully deuterated or fluorinated variants thereof.

[0092] In some embodiments of the compound represented by the structure selected from Group 2, m is 2.

[0093] In some embodiments of the compound represented by the structure selected from Group 2, R1 , R 2 , R 3 , R 4 , and R 5 is independently selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, and combinations thereof.

[0094] In some embodiments of the compound represented by the structure selected from Group 2, R 6 is selected from the group consisting of alkyl having at least 7 carbon atoms, cycloalkyl having at least 7 carbon atoms, alkyl-cycloalkyl having at least 7 carbon atoms, and partially or fully deuterated or fluorinated variants thereof.

[0095] In some embodiments of the compound represented by the structure selected from Group 2, R 3 , R 4 , and R 5 are each hydrogen.

[0096] In some embodiments of the compound represented by the structure selected from Group 2, L A is selected from the group consisting of the above L A1 to L A225 .

[0097] In some embodiments of the compound represented by the structure selected from Group 2, L B is selected from the group consisting of the above L B1 to L B227 . The structure of L B1 to L B227 is as shown above.

[0098] According to another aspect of the present disclosure, an OLED is disclosed, the OLED comprising an anode; a cathode; and an organic layer disposed between the anode and the cathode, the organic layer being

Chemical formula

Chemical formula

Chemical formula

[0099] In some embodiments, the OLED is incorporated into a device selected from the group consisting of consumer products, electronic component modules, and lighting panels.

[0100] In some embodiments of the OLED, the organic layer is a light-emitting layer, and the compound can be a light-emitting dopant or a non-light-emitting dopant.

[0101] As described in connection with the device structure shown in FIG. 1, other functional layers of the OLED can be present between the organic layer and the anode and / or between the organic layer and the cathode. Thus, depending on the specific embodiment, the organic layer containing the novel compound of the present disclosure may be deposited directly on the electrode substrate or on the intervening layer.

[0102] In some embodiments of the OLED, the organic layer further comprises a host, the host comprising a triphenylene containing a benzo-fused thiophene or a benzo-fused furan; the substituents in the host 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≡CC n H 2n+1 , Ar 1 , Ar 1 -Ar 2 , and C n H 2n -Ar 1 is a non-condensed substituent independently selected from the group consisting of, or is unsubstituted; n is from 1 to 10; Ar 1 and Ar 2 are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and their heteroaromatic analogs.

[0103] In some embodiments of the OLED, the organic layer further comprises a host, the host comprising at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

[0104] In some embodiments of the OLED, the organic layer further includes a host, and the host is selected from the group consisting of the following.

Chemical formula

Chemical formula

[0105] In some embodiments of the OLED, the organic layer further includes a host, and the host includes a metal complex.

[0106] In some embodiments, the compound can be a luminescent dopant. In some embodiments, the compound can generate luminescence through phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes.

[0107] According to another aspect, a composition is disclosed, and the composition includes a compound represented by a formula selected from the group consisting of the following.

Chemical formula

Chemical formula

Chemical formula

[0108] The OLEDs disclosed herein can be incorporated into one or more of consumer products, electronic component modules, and lighting panels. In some embodiments, the organic layer is a light-emitting layer, and the compound can be a light-emitting dopant or a non-light-emitting dopant. In another embodiment, the compound can be a non-light-emitting dopant.

[0109] The organic layer can also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the host used can be a material with a) bipolar, b) electron-transporting, c) host-transporting, or d) a wide bandgap that contributes little to charge transport. In some embodiments, the host can include a metal complex. The host can be a triphenylene containing a benzo-fused thiophene or a benzo-fused furan. The substituents in the host 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≡C-C n H 2n+1 Ar 1 Ar 1 -Ar 2 and C n H 2n -Ar 1is a non-condensed substituent independently selected from the group consisting of, or is unsubstituted. In the said substituent, n can be from 1 to 10; Ar 1 and Ar 2 are independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof. The host can be an inorganic compound. For example, Zn-containing inorganic compounds such as ZnS can be mentioned.

[0110] The host can be a compound containing at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene. The host can contain a metal complex. The host can be a specific compound selected from the group consisting of the following, but is not limited thereto.

Chemical formula

Chemical formula

[0111] In yet another aspect of the present disclosure, a composition containing a compound represented by formula I is described. The composition can contain one or more components selected from the group consisting of the solvents, hosts, hole injection materials, hole transport materials, and electron transport layer materials disclosed herein. Combinations with other materials

[0112] The materials described herein as useful for a particular layer in an organic light-emitting device can be used in combination with a wide variety of other materials present in the device. For example, the emissive dopants disclosed herein can be used in combination with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes, and other layers that may be present. The materials described or referenced below are non-limiting examples of materials that can be useful in combination with the compounds disclosed herein, and one of ordinary skill in the art can readily access the literature to identify other materials that can be useful in combination. Conductive dopant:

[0113] The charge transport layer is doped with a conductive dopant, which greatly changes the density of charge carriers and thereby its conductivity. Conductivity can be increased by generating charge carriers in the matrix material or depending on the type of dopant, and changes in the Fermi level of the semiconductor can also be achieved. The hole transport layer can be doped with a p-type conductive dopant, and the n-type conductive dopant is used in the electron transport layer.

[0114] Non-limiting examples of conductive dopants that can be used in an OLED in combination with the materials disclosed herein are exemplified below along with the literature disclosing these materials. EP01617493, EP01968131, EP2020694, EP2684932, US20050139810, US20070160905, US20090167167, US2010288362, WO06081780, WO2009003455, WO2009008277, WO2009011327, WO2014009310, US2007252140, US2015060804, US2012146012

Chemical formula

[0115] The hole injection / transport materials used in the embodiments of the present invention are not particularly limited, and any compound may be used as long as the compound is typically used as a hole injection / transport material. Examples of the materials include phthalocyanine or porphyrin derivatives; aromatic amine derivatives; indolocarbazole derivatives; polymers containing fluorohydrocarbons; polymers having a conductive dopant; conductive polymers such as PEDOT / PSS; self-assembled monomers derived from compounds such as phosphonic acids and silane derivatives; metal oxide derivatives such as MoO x and the like; p-type semiconductor organic compounds such as 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile; metal complexes, and crosslinkable compounds, but are not limited thereto.

[0116] Examples of the aromatic amine derivatives used in the HIL or HTL include, but are not limited to, those having the following general structure. [Chemical formula]

[0117] Ar 1 to Ar 9Each of them is selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene, etc.; dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine, etc.; and a group consisting of 2 to 10 cyclic structural units which are the same or different kinds of groups selected from an aromatic hydrocarbon cyclic group and an aromatic heterocyclic group, and are bonded to each other directly or via at least one of an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, a chain structural unit and an aliphatic cyclic group. Each Ar can be unsubstituted or substituted by a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino and combinations thereof.

[0118] In one embodiment, Ar 1 from Ar9 is selected independently from the group consisting of

Chem.

[0119] Examples of metal complexes used in HIL or HTL include, but are not limited to, the following general formula.

Chem.

[0120] In one embodiment, (Y 101 -Y 102 ) is a 2-phenylpyridine derivative. In another embodiment, (Y 101 -Y 102 ) is a carbene ligand. In another embodiment, Met is selected from Ir, Pt, Os, and Zn. In a further embodiment, the metal complex has a minimum oxidation potential of less than about 0.6 V in solution with respect to the Fc + / Fc couple.

[0121] Non-limiting examples of HIL materials and HTL materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below along with the literature disclosing these materials. CN102702075, DE102012005215, EP01624500, EP01698613, EP01806334, EP01930964, EP01972613, EP01997799, EP02011790, EP02055700, EP02055701, EP1725079, EP2085382, EP2660300, EP650955, JP07 - 073529, JP2005112765, JP2007091719, JP2008021687, JP2014 - 009196, KR20110088898, KR20130077473, TW201139402, US06517957, US20020158242, US20030162053, US20050123751, US20060182993, US20060240279, US20070145888, US20070181874, US20070278938, US20080014464, US20080091025, US20080106190, US20080124572, US20080145707, US20080220265, US20080233434, US20080303417, US2008107919, US20090115320, US20090167161, US2009066235, US2011007385, US20110163302, US2011240968, US2011278551, US2012205642, US2013241401, US20140117329, US2014183517, US5061569, US5639914, WO05075451, WO07125714, WO08023550, WO08023759, WO2009145016, WO2010061824, WO2011075644, WO2012177006, WO2013018530, WO2013039073, WO2013087142, WO2013118812, WO2013120577, WO2013157367, WO2013175747, WO2014002873, WO2014015935, WO2014015937, WO2014030872, WO2014030921, WO2014034791, WO2014104514, WO2014157018 [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] EBL:

[0122] The electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons emitted from the light-emitting layer. The presence of such a blocking layer in a device can result in significantly higher efficiency and / or longer lifetime compared to a similar device lacking the blocking layer. Also, the blocking layer can be used to limit light emission to a desired region of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or higher triplet energy than the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or higher triplet energy than one or more of the hosts closest to the EBL interface. In one aspect, the compound used in the EBL contains the same molecule or the same functional group as one of the hosts described below. Host:

[0123] The light-emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as a light-emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complex or organic compound may be used as long as the triplet energy of the host is larger than that of the dopant. Any host material may be used together with any dopant as long as the triplet criterion is satisfied.

[0124] Examples of the metal complex used as the host material preferably have the following general formula.

Chemical formula

[0125] In one aspect, the metal complex is the following complex.

Chemical formula

[0126] In another aspect, Met is selected from Ir and Pt. In a further aspect, (Y 103 -Y 104 ) is a carbene ligand.

[0127] Examples of other organic compounds used as hosts include aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and groups of the same or different types selected from aromatic hydrocarbon cyclic groups and aromatic heterocyclic groups, and consisting of 2 to 10 cyclic structural units bonded to each other directly or via at least one of an oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit, and aliphatic cyclic group. Each option in each group may be unsubstituted or substituted by a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0128] In one aspect, the host compound contains at least one of the following groups in the molecule.

Chemical formula

[0129] Non-limiting examples of host materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below together with the documents disclosing these materials. EP2034538, EP2034538A, EP2757608, JP2007254297, KR20100079458, KR20120088644, KR20120129733, KR20130115564, TW201329200, US20030175553, US20050238919, US20060280965, US20090017330, US20090030202, US20090167162, US20090302743, US20090309488, US20100012931, US20100084966, US20100187984, US2010187984, US2012075273, US2012126221, US2013009543, US2013105787, US2013175519, US2014001446, US20140183503, US20140225088, US2014034914, US7154114, WO2001039234, WO2004093207, WO2005014551, WO2005089025, WO2006072002, WO2006114966, WO2007063754, WO2008056746, WO2009003898, WO2009021126, WO2009063833, WO2009066778, WO2009066779, WO2009086028, WO2010056066, WO2010107244, WO2011081423, WO2011081431, WO2011086863, WO2012128298, WO2012133644, WO2012133649, WO2013024872, WO2013035275, WO2013081315, WO2013191404, WO2014142472

Chem.

Chem.

Chem.

Chem.

[0130] One or more further emitter dopants can be used in combination with the compounds of the present disclosure. Examples of further emitters are not particularly limited, and any compound can be used as long as the compound is typically used as an emitter material. Suitable emitter materials include, but are not limited to, compounds that can generate light through phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes.

[0131] Non-limiting examples of emitter materials that can be used in an OLED in combination with the materials disclosed herein are exemplified below along with the literature disclosing these materials. CN103694277, CN1696137, EB01238981, EP01239526, EP01961743, EP1239526, EP1244155, EP1642951, EP1647554, EP1841834, EP1841834B, EP2062907, EP2730583, JP2012074444, JP2013110263, JP4478555, KR1020090133652, KR20120032054, KR20130043460, TW201332980, US06699599, US06916554, US20010019782, US20020034656, US20030068526, US20030072964, US20030138657, US20050123788, US20050244673, US2005123791, US2005260449, US20060008670, US20060065890, US20060127696, US20060134459, US20060134462, US20060202194, US20060251923, US20070034863, US20070087321, US20070103060, US20070111026, US20070190359, US20070231600, US2007034863, US2007104979, US2007104980, US2007138437, US2007224450, US2007278936, US20080020237, US20080233410, US20080261076, US20080297033, US200805851, US2008161567, US2008210930, US20090039776, US20090108737, US20090115322, US20090179555, US2009085476, US2009104472, US20100090591, US20100148663, US20100244004, US20100295032, US2010102716, US2010105902, US2010244004, US2010270916, US20110057559, US20110108822, US20110204333, US2011215710, US2011227049, US2011285275,US2012292601, US20130146848, US2013033172, US2013165653, US2013181190, US2013334521, US20140246656, US2014103305, US6303238, US6413656, US6653654, US6670645, US6687266, US6835469, US6921915, US7279704, US7332232, US7378162, US7534505, US7675228, US7728137, US7740957, US7759489, US7951947, US8067099, US8592586, US8871361, WO06081973, WO06121811, WO07018067, WO07108362, WO07115970, WO07115981, WO08035571, WO2002015645, WO2003040257, WO2005019373, WO2006056418, WO2008054584, WO2008078800, WO2008096609, WO2008101842, WO2009000673, WO2009050281, WO2009100991, WO2010028151, WO2010054731, WO2010086089, WO2010118029, WO2011044988, WO2011051404, WO2011107491, WO2012020327, WO2012163471, WO2013094620, WO2013107487, WO2013174471, WO2014007565, WO2014008982, WO2014023377, WO2014024131, WO2014031977, WO2014038456, WO2014112450, [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] [Chemistry] HBL:

[0132] Using a hole blocking layer (HBL), the number of holes and / or excitons emitted from the light emitting layer can be reduced. The presence of such a blocking layer in the device can result in significantly higher efficiency and / or longer lifetime compared to a similar device lacking the blocking layer. Also, a blocking layer can be used to limit light emission to a desired region of the OLED. In some embodiments, the HBL material has a lower HOMO (farther from the vacuum level) and / or higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (farther from the vacuum level) and / or higher triplet energy than one or more of the hosts closest to the HBL interface.

[0133] In one aspect, the compound used in the HBL contains the same molecule as that used as the host described above.

[0134] In another aspect, the compound used in the HBL contains at least one of the following groups in the molecule. [Chemistry] where k is an integer from 1 to 20; L 101 is another ligand, and k' is an integer from 1 to 3. ETL:

[0135] The electron transport layer (ETL) may include materials capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or may be doped. Doping can be used to enhance conductivity. Examples of ETL materials are not particularly limited, and any metal complex or organic compound may be used as long as it is typically used for transporting electrons.

[0136] In one aspect, the compound used in the ETL contains at least one of the following groups in the molecule.

Chemical formula

[0137] In another aspect, the metal complex used in the ETL contains, but is not limited to, the following general formula.

Chemical formula

[0138] Non-limiting examples of ETL materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below together with the documents disclosing these materials. CN103508940, EP01602648, EP01734038, EP01956007, JP2004-022334, JP2005149918, JP2005-268199, KR0117693, KR20130108183, US20040036077, US20070104977, US2007018155, US20090101870, US20090115316, US20090140637, US20090179554, US2009218940, US2010108990, US2011156017, US2011210320, US2012193612, US2012214993, US2014014925, US2014014927, US20140284580, US6656612, US8415031, WO2003060956, WO2007111263, WO2009148269, WO2010067894, WO2010072300, WO2011074770, WO2011105373, WO2013079217, WO2013145667, WO2013180376, WO2014104499, WO2014104535.

Chem.

Chem.

Chem.

[0139] In tandem or stacked OLEDs, the CGL plays an important role in performance and consists of an n-doped layer and a p-doped layer for electron and hole injection, respectively. Electrons and holes are supplied from the CGL and the electrodes. The consumed electrons and holes in the CGL are refilled by the electrons and holes injected from the cathode and anode, respectively, and then the bipolar current gradually reaches a stable state. Typical CGL materials include n-type and p-type conductive dopants used in the transport layer.

[0140] In any of the above-mentioned compounds used in each layer of the OLED device, a hydrogen atom may be partially or fully deuterated. Thus, any specifically mentioned substituents such as, but not limited to, methyl, phenyl, pyridyl, etc. can also be their non-deuterated, partially deuterated, and fully deuterated versions. Similarly, classes of substituents such as, but not limited to, alkyl, aryl, cycloalkyl, heteroaryl, etc. can also be their non-deuterated, partially deuterated, and fully deuterated versions.

Example

[0141] Synthesis Example

[0142] 1.Comp(L A1 ) 2 Ir(L B227 ) Synthesis

Chem.

[0143] 2.Comp(L A147 ) 2 Ir(LB184 ) Synthesis

Chem.

[0144] 3.Comp(L A147 ) 2 Ir(L B86 ) Synthesis

Chem.

[0145] 4.Comp(L A147 ) 2 Ir(L B109 ) Synthesis

Chem.

Chemical formula

Chemical formula

[0146] 5.Comp(L A147 ) 2 Ir(L B88 ) Synthesis

Chemical formula

Chem.

Chem.

Chem.

[0147] 6.Comp(L A147 ) 2 Ir(L B225 ) Synthesis

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0148] 7.Comp(L A153 ) 2 Ir(L B86 ) Synthesis

Chemical formula

[0149] All of the example devices were fabricated by thermal evaporation under high vacuum (<10 -7 Torr). The anode electrode was indium tin oxide (ITO) with a thickness of 750 Å. The cathode consisted of 10 Å of Liq (lithium 8-hydroxyquinolate) and 1,000 Å of Al. Immediately after fabrication, the devices were encapsulated with a glass lid sealed with epoxy resin in a nitrogen glove box (H 2 O and O 2 was <1 ppm), and a moisture getter was placed in the package. The laminate of the device example consisted of, in order from the ITO surface, 100 Å of HATCN as a hole injection layer (HIL), 450 Å of HTM as a hole transport layer (HTL), 50 Å of EBM as an electron blocking layer, a 400 Å emitting layer (EML) containing a two-component host (H1:H2 ratio 1:1) and 12% of a phosphor (the present invention or a comparative luminescent example), and 350 Å of Liq (lithium 8-hydroxyquinolate) doped with 40% of ETM as an electron transport layer ETL. The chemical structures of the device materials are shown below. [Chemical formula]

[0150] Table 5 shows the thickness and materials of the layers of the device. Table 5 Device structure for evaluating the EQE of the yellow emitter

Table 5

[0151] Using emitter Examples 1, 2, 5, 7, 8, 9, 10 and CE2, the correlation between device EQE and emitter orientation factor was shown. The device EQE measured at 1,000 nits is shown in Table 6. Table 6 Correlation between experimental EQE, estimated EQE in the device, and PLQY and orientation factor of the emitter

Table 6

[0152] It is understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein can be replaced with other materials and structures without departing from the spirit of the invention. Accordingly, the invention as claimed may include variations from the specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It is understood that the various theories as to why the invention works are not intended to be limiting.

Prior Art Documents

Patent Documents

[0153]

Patent Document 1

Patent Document 2

[0154] 100 Organic Light-Emitting Device 110 Substrate 115 Anode 120 Hole Injection Layer 125 Hole Transport Layer 130 Electron Blocking Layer 135 Light-Emitting Layer 140 Hole Blocking Layer 145 Electron Transport Layer 150 Electron Injection Layer 155 Protection Layer 160 Cathode 162 First Conductive Layer 164 Second Conductive Layer 170 Barrier Layer 200 Inverted OLED, Device 210 Substrate 215 Cathode 220 Light-Emitting Layer 225 Hole Transport Layer 230 Anode

Claims

1. Formula M(L Ａ ) ｈ (L Ｂ ) ｙ (L Ｃ ) ｚ The organic layer comprises a compound represented by the formula: (In the formula, the ligand L Ａ , L Ｂ , and L Ｃ are each independently selected from the group consisting of: 【Chemistry 1】 【Chemistry 2】 In the formula, X １ ~X １３ are each independently selected from the group consisting of carbon and nitrogen; X is BR', NR', PR', O, S, Se, C=O, S=O, SO ２ , CR′R″, SiR′R″, and GeR′R″; R′ and R″ may be fused or joined to form a ring; R ａ , R ｂ , R ｃ , and R ｄ can each represent mono-substitution to the maximum number of substitutions possible, or no substitution; R', R'', R ａ , R ｂ , R ｃ , and R ｄ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; R ａ , R ｂ , R ｃ , and R ｄ any two adjacent substituents of may be fused or linked to form a ring or a multidentate ligand; M is a metal having an atomic weight greater than 40; h is 1 or 2; y is 0, 1, or 2; z is 0, 1, or 2; h+y+z is the oxidation state of the metal M; The compound has a molecular orientation factor value of greater than 0.

67.

2. 2. The organic layer of claim 1, wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu.

3. R ａ , R ｂ , R ｃ , and R ｄ is monosubstituted having at least 13 carbon atoms, and R ａ , R ｂ , R ｃ , and R ｄ and the remainder all have a maximum carbon number of 6.

4. X １ ~X １３ The organic layer of claim 1 , wherein each of is carbon.

5. Formula Ir(L Ａ ) ２ (L Ｂ The organic layer according to claim 1 , wherein

6. L Ａ is represented by a formula selected from the group consisting of: 【Chemistry 3】 L Ｂ The organic layer according to claim 5 , wherein: 【Chemistry 4】

7. L Ａ and L Ｂ 6. The organic layer of claim 5, wherein: 【Chemistry 5】 【Chemistry 6】

8. L Ａ and L Ｂ 6. The organic layer of claim 5, wherein each is independently selected from the group consisting of: 【Chemistry 7】 【Chemistry 8】

9. The compound has the formula Pt(L Ａ ) (L Ｂ ) (in the formula, L Ａ and L Ｂ The organic layer according to claim 1 , wherein

10. The compound is represented by a structure selected from the group consisting of: Ａ ) ｍ Ir(L Ｂ ) ３－ｍ The organic layer according to claim 1 , wherein 【Chemistry 9】 wherein m is 1 or 2; R １ , R ２ , R ４ , and R ５ each independently represent mono-, di-, tri-, or tetra-substitution, or represent unsubstitution; R ３ represents mono-, di-, or tri-substitution, or represents unsubstitution; R １ , R ２ , R ３ , R ４ , and R ５ are each independently selected from the group consisting of hydrogen, deuterium, C1-C6 alkyl, C1-C6 cycloalkyl, and partially or fully deuterated or fluorinated variants thereof; R ６ is selected from the group consisting of alkyl having at least 7 carbon atoms, cycloalkyl having at least 7 carbon atoms, alkyl-cycloalkyl having at least 7 carbon atoms, and partially or fully deuterated or fluorinated variants thereof.

11. Formula (L) represented by a structure selected from the group consisting of Ａ ) ｍ Ir(L Ｂ ) ３－ｍ An organic layer comprising a compound represented by the formula: 【Chemistry 10】 wherein m is 1 or 2; R １ , R ２ , R ４ , and R ５ each independently represent mono-, di-, tri-, or tetra-substitution, or represent unsubstitution; R ３ represents mono-, di-, or tri-substitution, or represents unsubstitution; R ６ represents mono-substitution or represents no substitution; R １ , R ２ , R ３ , R ４ , R ５ , and R ６ are each independently selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, partially or fully deuterated or fluorinated variants thereof, and combinations thereof.

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