Organic electroluminescent device

Abstract

The invention relates to an organic electroluminescent device. An OLED structure is disclosed that includes a first organic layer disposed between an anode and a cathode. The first organic layer comprises a primary phosphorescent emitter and a first host, and wherein one of the following conditions is true: (1) the first organic layer further comprises a secondary emitter; or (2) the OLED further includes a second organic layer disposed between the anode and the cathode, wherein the second organic layer includes a secondary emitter. The peak emission wavelength [lambda] max of the phosphorescent emitter is > = 600 nm and < = 750 nm, the peak emission wavelength [lambda] max of the secondary emitter is > = 750 nm, and the lowest excited state triplet energy T1 of the first host is at least 0.1 eV higher than the lowest excited state triplet energy T1 of the primary phosphorescent emitter.

Description

[0001] This application is a divisional application of the invention patent application with the application date of November 6, 2018, application number 201811311919.7, and invention name “Organic electroluminescent device”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62 / 582,359, filed on November 7, 2017, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The invention relates to organic light emitting diodes. Background Art

[0005] Optoelectronic devices utilizing organic materials are becoming increasingly popular for a variety of reasons. Many of the materials used to make the devices are relatively inexpensive, so organic optoelectronic devices have the potential to have cost advantages over inorganic devices. In addition, the inherent properties of organic materials (e.g., their flexibility) can make them more suitable for specific applications, such as manufacturing 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 of light emitted by the organic emissive layer can generally be easily adjusted with appropriate dopants.

[0006] OLEDs utilize organic thin films that emit light when voltage is applied to the device. OLEDs are becoming an increasingly popular technology for applications such as flat panel displays, lighting, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

[0007] One application of phosphorescent emitting molecules is full-color displays. Industry standards for such displays require pixels that are suitable for emitting specific colors (called "saturated" colors). Specifically, these standards require saturated red, green, and blue pixels. Alternatively, OLEDs can be designed to emit white light. In conventional liquid crystal displays, an absorption filter is used to filter the emission from a white backlight to produce red, green, and blue emissions. The same technology can also be used for OLEDs. White OLEDs can be single EML devices or stacked structures. Color can be measured using CIE coordinates well known in the art.

[0008] An example of a green emitting molecule is tris(2-phenylpyridine)iridium, denoted Ir(ppy)3, which has the following structure:

[0009]

[0010] In this figure and the following figures, we depict the coordinate bonds of nitrogen to the metal (here Ir) as straight lines.

[0011] As used herein, the term "organic" includes polymeric materials and small molecule organic materials that can be used to make organic optoelectronic devices. "Small molecule" refers to any organic material that is not a polymer, and a "small molecule" may actually be quite large. In some cases, a small molecule may include a repeating unit. For example, the use of a long chain alkyl group as a substituent does not remove a molecule from the "small molecule" category. Small molecules can also be incorporated into polymers, for example as a side group on a polymer backbone or as part of a backbone. Small molecules can also serve as the core portion of a dendritic polymer, which consists of a series of chemical shells built on the core portion. The core portion of a dendritic polymer can be a fluorescent or phosphorescent small molecule emitter. A dendritic polymer can be a "small molecule", and all dendritic polymers currently used in the field of OLEDs are considered to be small molecules.

[0012] As used herein, "top" means farthest from the substrate, while "bottom" means closest to the substrate. Where a first layer is described as being "disposed "above" a 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 and second layers. For example, a cathode may be described as being "disposed "above" an anode even though various organic layers are present between the cathode and the anode.

[0013] As used herein, "solution processable" means capable of being dissolved, dispersed or transported in and / or deposited from a liquid medium in the form of a solution or suspension.

[0014] When a ligand is believed to directly contribute to the photosensitive property of an emissive material, the ligand may be referred to as "photosensitive." When a ligand is believed not to contribute to the photosensitive property of an emissive material, the ligand may be referred to as "ancillary," but the ancillary ligand may alter the properties of the photosensitive ligand.

[0015] As used herein, and as will be generally understood by one skilled in the art, a first "Highest Occupied Molecular Orbital" (HOMO) or "Lowest Unoccupied Molecular Orbital" (LUMO) energy level is "greater than" or "higher than" a 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 energy level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (a less negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (a less negative EA). On a conventional energy level diagram with the vacuum energy 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 closer to the top of this diagram than a "lower" HOMO or LUMO energy level.

[0016] As used herein, and as one skilled in the art would generally understand, a first work function is "greater than" or "higher than" a second work function if the first work function has a higher absolute value. Because work functions are typically measured as negative numbers relative to the vacuum level, this means that a "higher" work function is more negative. On a conventional energy level diagram with the vacuum level at the top, a "higher" work function is illustrated as being farther away from the vacuum level in a downward direction. Thus, the definition of HOMO and LUMO energy levels follows different rules than work functions.

[0017] More details regarding OLEDs and the definitions set forth above can be found in U.S. Patent No. 7,279,704, which is incorporated herein by reference in its entirety. Summary of the invention

[0018] Near-infrared (NIR) OLEDs can have a variety of applications, including imaging, night vision, and drug therapy. While utilizing phosphorescence in OLEDs provides a mechanism to greatly improve device efficiency, fluorescent emitters and lanthanide-based emitters can offer some unique advantages in the regime of NIR energy excitons, such as shorter excited state lifetimes, higher emission quantum yields, and narrow spectral line shape emissions.

[0019] In order to combine the efficiency benefits of phosphorescent OLED materials with the advantages of other emitters, we add secondary NIR emitters to the phosphorescent OLED device structure, where the primary phosphorescent emitter acts as a sensitizer for the secondary NIR emitter. The secondary NIR emitter can be a lanthanide complex, an organic fluorophore, or a doublet emitter. In this configuration, the emission layer (EML) of the phosphorescent OLED with the primary phosphorescent emitter dopant can be uniformly or non-uniformly (gradient, bands of varying concentrations, etc.) co-doped with the secondary NIR emitter. Alternatively, the secondary NIR emitter can be provided as a separate discrete layer within or adjacent to the EML where energy transfer can occur,

[0020] An OLED is disclosed, comprising an anode, a cathode, and a first organic layer disposed between the anode and the cathode. The first organic layer comprises a primary phosphorescent emitter and a first host, and wherein one of the following conditions is true: (1) the first organic layer further comprises a secondary emitter; or (2) the OLED further comprises a second organic layer disposed between the anode and the cathode, wherein the second organic layer comprises a secondary emitter. The peak emission wavelength λmax of the phosphorescent emitter is ≥600 nm and ≤750 nm. The peak emission wavelength λmax of the secondary emitter is ≥750 nm. The lowest excited triplet energy T1 of the first host is at least 0.1 eV higher than the lowest excited triplet energy T1 of the phosphorescent emitter.

[0021] A consumer product including the OLED is also disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The illustrations are schematic and the structures shown are not to scale.

[0023] Figure 1 An organic light emitting device is shown.

[0024] Figure 2 An inverted organic light-emitting device without a separate electron transport layer is demonstrated.

[0025] Figure 3 Example OLED stacks are shown that incorporate separate emitting layers to physically separate the primary and secondary emitters. DETAILED DESCRIPTION

[0026] In general, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When an electric current is applied, the anode injects holes and the cathode injects electrons into the organic layer. The injected holes and electrons each migrate toward the oppositely charged electrode. When electrons and holes are localized on the same molecule, an "exciton" is formed, which is a localized electron-hole pair with an excited energy state. When the exciton relaxes through a light emission mechanism, light is emitted. In some cases, the exciton can be localized on an excimer or an excited complex. Non-radiative mechanisms (such as thermal relaxation) may also occur, but are generally considered undesirable.

[0027] The first OLEDs used emissive molecules that emitted light from a singlet state ("fluorescence"), as disclosed, for example, in US Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescence emission typically occurs in a time frame of less than 10 nanoseconds.

[0028] Recently, OLEDs with emissive materials that emit light from triplet states ("phosphorescence") have been demonstrated. Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices", Nature, Vol. 395, 151-154, 1998 ("Baldo-I"); and Baldo et al., "Very high-efficiency green organic light-emitting devices based on electrophosphorescence", Appl. Phys. Lett., Vol. 75, Nos. 3, 4-6 (1999) ("Baldo-II"), which are incorporated by reference in their entirety. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704, Columns 5-6, which is incorporated by reference.

[0029] Figure 1An organic light-emitting device 100 is shown. The figure is not necessarily drawn to scale. The 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, an emission 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 blocking layer 170. The cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. The device 100 can be manufactured by depositing the layers in sequence. The properties and functions of these various layers and example materials are described in more detail in US 7,279,704, columns 6-10, which are incorporated by reference.

[0030] More examples of each of these layers 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 m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. Examples of luminescent and host materials are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, disclose examples of cathodes comprising a composite cathode having a thin layer of a metal (e.g., Mg:Ag) with an overlying transparent, conductive, sputter-deposited ITO layer. The theory and use of barrier 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 by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety.

[0031] Figure 2An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 can be manufactured by depositing the layers in order. Because the most common OLED configuration has a cathode disposed above the anode, and device 200 has cathode 215 disposed below anode 230, device 200 can be referred to as an "inverted" OLED. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 An example is provided of how some layers may be omitted from the structure of device 100 .

[0032] Figure 1 and 2 The simple layered structures described in are provided by way of non-limiting examples, and it should be understood that embodiments of the present invention may be used in conjunction with various other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs may be obtained by combining the various layers described in different ways, or the layers may be omitted entirely based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than the specifically described materials may be used. Although many of the examples provided herein describe the various layers as comprising a single material, it should be understood that a combination of materials may be used, such as a mixture of a host and a dopant, or more generally, a mixture. In addition, the layers may have various sublayers. 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 emissive layer 220, and may be described as a hole transport layer or a hole injection layer. In one embodiment, the OLED may be described as having an "organic layer" disposed between a cathode and an anode. This organic layer may include a single layer, or may further include, for example, Figure 1 and 2 Multiple layers of said different organic materials.

[0033] Structures and materials not specifically described may also be used, such as OLEDs containing polymeric materials (PLEDs), such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of another example, an OLED having a single organic layer may be used. OLEDs may be stacked, such as described in U.S. Pat. No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures may deviate from Figure 1 and 2For example, the substrate may include angled reflective surfaces to improve out-coupling, such as a mesa structure as described in U.S. Pat. No. 6,091,195 to Forrest et al., and / or a pit structure as described in U.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entirety.

[0034] Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, inkjet (as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, incorporated by reference in their entirety), organic vapor phase deposition (OVPD) (as described in U.S. Pat. No. 6,337,102 to Forrest et al., incorporated by reference in their entirety), and deposition by organic vapor jet printing (OVJP) (as described in U.S. Pat. No. 7,431,968, incorporated by reference in their entirety). Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably carried out in nitrogen or an inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entirety), and patterning associated with some of the deposition methods such as inkjet and organic vapor jet printing (OVJP). Other methods may also be used. The material to be deposited may be modified to make it compatible with a specific deposition method. For example, branched or unbranched substituents such as alkyl and aryl groups, preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to withstand solution processing. Substituents having 20 or more carbons may be used, and 3 to 20 carbons are a preferred range. Materials having asymmetric structures may have better solution processability than materials having symmetric structures because asymmetric materials may have a lower tendency to recrystallize. Dendritic polymer substituents may be used to enhance the ability of small molecules to withstand solution processing.

[0035] The device manufactured according to the embodiment of the present invention may further optionally include a barrier layer. One purpose of the barrier layer is to protect the electrode and the organic layer from exposure to harmful substances in an environment including moisture, steam and / or gas. The barrier layer can be deposited on a substrate, an electrode, under a substrate, an electrode, or beside a substrate, an electrode, or on any other part (including the edge) of the device. 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 a composition having a single phase and a composition having multiple phases. Any suitable material or material combination may be used for the barrier layer. The barrier layer may be combined with an inorganic compound or an organic compound or both. A preferred barrier layer includes a mixture of a polymeric material and a non-polymeric material, as described in U.S. Patent No. 7,968,146, PCT Patent Application No. PCT / US2007 / 023098, and No. PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. In order to be considered a "mixture", the aforementioned polymeric material and non-polymeric material constituting the barrier layer should be deposited under the same reaction conditions and / or deposited simultaneously. The weight ratio of polymeric material to non-polymeric material can be in the range of 95:5 to 5:95. The polymeric material and non-polymeric material can be produced from the same precursor material. In one example, the mixture of polymeric material and non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

[0036] Devices manufactured according to embodiments of the present invention may be incorporated into a wide variety of electronic component modules (or units), which may be incorporated into a variety of electronic products or intermediate components. Examples of electronic 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. The electronic component module may optionally include drive electronics and / or a power supply. Devices manufactured according to embodiments of the present invention may be incorporated into a wide variety of consumer products, which have one or more electronic component modules (or units) incorporated therein. A consumer product comprising an OLED is disclosed, wherein the OLED includes a compound of the present disclosure in an organic layer in the OLED. The consumer product should include any kind of product containing one or more of one or more light sources and / or a certain type of visual display. Some examples of such consumer products include flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, cellular phones, tablet computers, tablet phones, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, microdisplays (displays with a diagonal of less than 2 inches), 3-D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screens, light therapy devices, and signage. Various control mechanisms can be used to control devices made according to the present invention, including passive matrices and active matrices. Many of the devices are intended to be used in a temperature range that is comfortable for humans, such as 18 degrees Celsius to 30 degrees Celsius, and more preferably at room temperature (20-25 degrees Celsius), but can be used outside this temperature range (e.g., -40 degrees Celsius to +80 degrees Celsius).

[0037] The materials and structures described herein can be applied to devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can employ the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0038] The terms "halo," "halogen," or "halide" are used interchangeably and refer to fluorine, chlorine, bromine, and iodine.

[0039] The term "acyl" refers to a substituted carbonyl (C(O)-R s ).

[0040] The term "ester" refers to a substituted oxycarbonyl (-OC(O)-R sOR-C(O)-OR s ) group.

[0041] The term "ether" refers to -OR s Group.

[0042] The terms "thio" or "thioether" are used interchangeably and refer to -SR s Group.

[0043] The term "sulfinyl" refers to -S(O)-R s Group.

[0044] The term "sulfonyl" refers to -SO2-R s Group.

[0045] The term "phosphino" refers to -P(R s )3 groups, wherein each R s Can be the same or different.

[0046] The term "silyl" refers to -Si(R s )3 groups, wherein each R s Can be the same or different.

[0047] In each of the above, R s It may be hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof. s Selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0048] The term "alkyl" refers to and includes straight and branched chain alkyl groups. Preferred alkyl groups are those containing one to fifteen carbon atoms and include methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and the like. In addition, the alkyl group may be optionally substituted.

[0049] The term "cycloalkyl" refers to and includes monocyclic, polycyclic and spiroalkyl groups. Preferred cycloalkyl groups are cycloalkyl groups containing 3 to 12 ring carbon atoms and include cyclopropyl, cyclopentyl, cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl, adamantyl, etc. In addition, the cycloalkyl group may be optionally substituted.

[0050] The term "heteroalkyl" or "heterocycloalkyl" refers to an alkyl or cycloalkyl group, respectively, having at least one carbon atom replaced by a heteroatom. Optionally, the at least one heteroatom is selected from O, S, N, P, B, Si and Se, preferably O, S or N. In addition, the heteroalkyl or heterocycloalkyl group is optionally substituted.

[0051] The term "alkenyl" refers to and includes straight and branched alkenyl groups. Alkenyl groups are essentially alkyl groups that include at least one carbon-carbon double bond in the alkyl chain. Cycloalkenyl groups are essentially cycloalkyl groups that include at least one carbon-carbon double bond in the cycloalkyl ring. As used herein, the term "heteroalkenyl" refers to an alkenyl group in which at least one carbon atom is replaced by a heteroatom. Optionally, the at least one heteroatom is selected from O, S, N, P, B, Si and Se, preferably O, S or N. Preferred alkenyl, cycloalkenyl or heteroalkenyl groups are those containing two to fifteen carbon atoms. In addition, alkenyl, cycloalkenyl or heteroalkenyl groups are optionally substituted.

[0052] The term "alkynyl" refers to and includes straight chain and branched chain alkynyl groups. Preferred alkynyl groups are those containing two to fifteen carbon atoms. In addition, the alkynyl group is optionally substituted.

[0053] The terms "aralkyl" or "arylalkyl" are used interchangeably and refer to an alkyl group substituted with an aryl group. Additionally, the aralkyl group is optionally substituted.

[0054] The term "heterocyclic group" refers to and includes aromatic and non-aromatic cyclic groups containing at least one heteroatom. Optionally, the at least one heteroatom is selected from O, S, N, P, B, Si and Se, preferably O, S or N. Aromatic heterocyclic groups can be used interchangeably with heteroaryl. Preferred non-aromatic heterocyclic groups are heterocyclic groups containing 3 to 7 ring atoms including at least one heteroatom, and include cyclic amines, such as morpholinyl, piperidinyl, pyrrolidinyl, etc., and cyclic ethers / thioethers, such as tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, etc. In addition, heterocyclic groups can be optionally substituted.

[0055] The term "aryl" refers to and includes monocyclic aromatic hydrocarbon groups and polycyclic aromatic ring systems. Polycyclic rings may have two or more rings in which two carbons are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, for example, the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocyclic and / or heteroaryl. Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty carbon atoms, and more preferably six to twelve carbon atoms. Particularly preferred are aryl groups having six carbons, ten carbons or twelve carbons. Suitable aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthrene, fluorene, pyrene, Perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. In addition, the aryl group is optionally substituted.

[0056] The term "heteroaryl" refers to and includes both monocyclic heteroaromatic groups and polycyclic aromatic ring systems including at least one heteroatom. Heteroatoms include, but are not limited to, O, S, N, P, B, Si and Se. In many cases, O, S or N are preferred heteroatoms. Monocyclic heteroaromatic systems are preferably monocyclic rings with 5 or 6 ring atoms, and the rings may have one to six heteroatoms. Heteropolycyclic ring systems may have two or more rings in which two atoms are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is a heteroaryl, for example, the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocycle and / or heteroaryl. Heteropolycyclic aromatic ring systems may have one to six heteroatoms on each ring of the polycyclic aromatic ring system. Preferred heteroaryls are heteroaryls containing three to thirty carbon atoms, preferably three to twenty carbon atoms, and more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridyl indole, 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, quinazole In some embodiments, the heteroaryl group may be substituted with 1,2-azaborane, 1,3-azaborane, 1,4-azaborane, borazine and aza analogs thereof.

[0057] Among the aryl and heteroaryl groups listed above, the groups of triphenylene, naphthalene, anthracene, dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, pyrazine, pyrimidine, triazine and benzimidazole and their respective corresponding aza analogs are of particular interest.

[0058] As used herein, the terms alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aralkyl, heterocyclyl, aryl and heteroaryl are independently unsubstituted or substituted with one or more typical substituents.

[0059] In many cases, the general substituent is selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, cycloamino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0060] In some cases, preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, thio, and combinations thereof.

[0061] In some cases, preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy, aryloxy, amino, silane, aryl, heteroaryl, thio, and combinations thereof.

[0062] In other cases, more preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0063] The terms "substituted" and "substituted" refer to the bonding of a substituent other than H to the relevant position, such as carbon or nitrogen. For example, when R 1 When it represents a single substitution, then one R 1 must not be H (i.e. substituted). Similarly, when R 1 When it represents disubstituted, then R 1 Two of them must not be H. Similarly, when R 1 When there is no substitution, R 1 For example, it can be hydrogen with available valences for the ring atoms, such as the carbon atoms of benzene and the nitrogen atoms in pyrrole, or simply none for ring atoms with fully saturated valences, such as the nitrogen atoms in pyridine. The maximum number of substitutions possible in the ring structure will depend on the total number of available valences among the ring atoms.

[0064] As used herein, "combinations thereof" means that one or more members of the applicable list are combined to form a known or chemically stable arrangement that a person of ordinary skill in the art can envision from the applicable list. For example, alkyl and deuterium can be combined to form partially or fully deuterated alkyl; halogen and alkyl can be combined to form haloalkyl substituents; and halogen, alkyl and aryl can be combined to form haloaralkyl. In one example, the term substitution includes a combination of two to four listed groups. In another example, the term substitution includes a combination of two to three groups. In yet another example, the term substitution includes a combination of two groups. Preferred combinations of substituents are combinations containing up to fifty atoms that are not hydrogen or deuterium, or combinations including up to forty atoms that are not hydrogen or deuterium, or combinations including up to thirty atoms that are not hydrogen or deuterium. In many cases, preferred combinations of substituents will include up to twenty atoms that are not hydrogen or deuterium.

[0065] The "aza" designation in the fragments described herein, i.e., aza-dibenzofuran, aza-dibenzothiophene, etc., means that one or more of the CH groups in the corresponding fragment can be replaced by a nitrogen atom, for example and without any limitation, azatriphenylene encompasses dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. Other nitrogen analogs of the aza-derivatives described above can be readily envisioned by one of ordinary skill in the art, and all such analogs are intended to be covered by the term as set forth herein.

[0066] As used herein, "deuterium" refers to an isotope of hydrogen. Deuterated compounds can be easily prepared using methods known in the art. For example, U.S. Patent No. 8,557,400, Patent Publication No. WO 2006 / 095951 and U.S. Patent Application Publication No. US2011 / 0037057 (which are incorporated herein by reference in their entirety) describe the preparation of deuterium-substituted organometallic complexes. Further reference is made to Ming Yan et al., Tetrahedron 2015, 71, 1425-30 and Atzrodt et al., Angew. Chem. Int. Ed. (Review) 2007, 46, 7744-65 (which are incorporated by reference in their entirety) respectively describe the deuteration of methylene hydrogen in benzylamine and the effective way to replace aromatic ring hydrogen with deuterium.

[0067] It should be understood that when a molecular fragment is described as a substituent or otherwise attached to another part, its name can be written as if it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or as if it is a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of naming substituents or attaching fragments are considered equivalent.

[0068] In the OLEDs disclosed herein, the primary phosphorescent emitters based on organometallics act as charge traps and thus act as preferred sites for exciton formation. These excitons subsequently transfer their energy to the secondary NIR emitters via Forster or Dexter energy transfer, depending on the emission mode of the secondary NIR emitters.

[0069] When the secondary NIR emitter consists of a lanthanide ligand field emitter, direct Dexter energy transfer from the primary phosphorescent emitter to the ligands and / or f orbitals of the lanthanide complex ultimately produces lanthanide f orbital centered excitons, which can serve as efficient emitting states. In this OLED structure, the energy transfer of the primary phosphor exciton to the secondary NIR emitter must be an energetically favorable process. Therefore, the primary phosphorescent emitter emits in the visible range, preferably in the red (600nm≤λ max ≤750nm) range can have excited state energy.

[0070] More specifically, with respect to the case where the secondary NIR emitter is a lanthanide compound and the emitting layer comprises at least three components, including a host material, a first transition metal phosphorescent compound (M 1 L 1 n ) as the primary phosphorescent emitter, and the second transition metal compound (M 2 L 2 n ) as a secondary NIR emitter. The first metal M 1 The second metal M is selected from the group consisting of: Os, Ir, Pd, Pt, Cu, Ag and Au. 2 The first transition metal phosphorescent compound will have a minimum triplet excited state energy T1, which is equal to or higher than the emission ff transition energy E of the second transition metal compound. (f-f) The excitons formed on the first transition metal compound will most likely transfer energy via the Dexter process to form excited states of the second transition metal compound. This device architecture enables complete or near-complete energy transfer from the primary emitter to the secondary NIR emitter. The lanthanide compound, the second transition metal compound, acts as the emitter in the OLED device.

[0071] Emission ff transition energy E of lanthanide compounds (f-f) This is shown in Table 1. In the last column of Table 1, the ff transition energy is given in nm, which is also the emission wavelength.

[0072] Table 1:

[0073]

[0074] When the secondary NIR emitter consists of a NIR fluorophore (such as cyanine, phthalocyanine, porphyrin, rhodamine or other classes of NIR emitters), the primary phosphor must preferably transfer its energy to the secondary NIR emitter via Förster energy transfer to avoid filling the fluorophore triplet states which would result in wasted non-emitting excited states. This condition requires optimization of (i) the spectral overlap between the emission spectrum of the primary phosphorescent emitter and the absorption spectrum of the secondary NIR emitter and (ii) spatial (molecular) and / or device optimization of the binary emitter system to prevent undesired Förster energy transfer.

[0075] In most cases, the spectral overlap condition of the primary phosphorescent emitter and the secondary NIR emitter will require the primary phosphorescent emitter to be a red phosphorescent emitter. max Secondary NIR (fluorescent) emitters with relatively small (<50 nm) Stokes shifts between 750 nm and 850 nm and absorption tailing into the red (600-650 nm), such as cyanine dyes, are suitable red phosphorescent emitters for efficient Forster energy transfer (emission λ in this system). max ). However, for any given NIR emitter, the primary phosphorescent red emitter may require optimization for efficient energy transfer. Preferably, the primary phosphorescent emitter emits λ max Absorption λ of the secondary NIR emitter max The offset is less than 200 nm, and more preferably less than 150 nm.

[0076] In the case of fluorescent emitters that are secondary NIR emitters, additional molecular and / or device precautions may need to be taken to avoid Dexter energy transfer, thereby preventing the detrimental formation of fluorophore triplet excitons. Such precautions may include bulky substituents (isopropyl, neopentyl, tert-butyl, adamantyl, etc.) on the primary or secondary emitters to increase the primary and secondary emitter distances and minimize the wave function overlap required for Dexter energy transfer. Such bulky substituents are particularly useful on secondary NIR emitters so as not to disrupt the charge transport, voltage, and other device properties of the EML and to electronically separate the secondary NIR emitter from the EML system. Bulky substituents can be particularly effective in preventing Dexter energy transfer when added directly to the π system of the emitter in order to prevent π orbital overlap.

[0077] Because the rate of Dexter's energy transfer is proportional to e -r(where r is the donor-acceptor radius (in this case the distance between two adjacent primary phosphorescent emitters and the secondary NIR emitter)), so this process can also be suppressed by reduced doping of secondary NIR emitters away from the charge recombination zone (e.g., preferably on the ETL side of the EML) or selective doping of secondary NIR emitters. These device structures will increase the effective emitter distance and reduce the rate of undesired Dexter energy transfer.

[0078] Reducing the Dexter energy transfer rate by physically separating the two emitters can be achieved via three strategies: (A) spatially separating the primary and secondary emitters by confining an emitter separation layer during device fabrication; (B) judiciously selecting the emitter doping percentages or concentrations to statistically minimize the probability of the primary and secondary emitters being within the Dexter energy transfer radius; and (C) spatially preventing the emitters from being within the Dexter energy transfer radius by introducing sufficient non-conjugated spatial volume into one or both of the emitters.

[0079] In case (A), the physical separation is caused by including the primary and secondary emitters in different layers of the device. In this article, the two emitting layers (one layer containing the primary phosphorescent emitter material and the other layer containing the secondary NIR emitter material) are separated by one or more layers of host or transmission material to achieve an interlayer separation distance greater than 1 nm, more preferably greater than 2 nm, and more preferably greater than 4 nm.

[0080] In cases (B) and (C), the primary and secondary emitters are doped in the same layer and the physical separation between the primary and secondary emitters can be described by the distance between the aromatic π systems of the two emitters, i.e. the donor-acceptor radius r. To minimize Dexter energy transfer, r is preferably greater than More preferably greater than and more preferably greater than

[0081] In case (C), where this is achieved by controlling the composition of the co-doped layer, the distance r should be primarily controlled by the concentrations of the two most abundant dopants. Assuming uniform distribution of the dopants within the host matrix and the hexagonal close-packed structure, the concentrations of both dopants should be less than 10%, more preferably less than 5%, and more preferably less than 3%. It is also advantageous to have one dopant that is less abundant than the majority dopant.

[0082] In case (C), where the intramolecular separation is caused by pendant steric volume on one or both dopants, the spacing provided by the steric volume can be roughly described by the difference in distances between the dopant mass center and: (a) the farthest aromatic carbon or heteroatom in the dopant; and (b) the farthest non-aromatic atom in the dopant. When only one of the two dopants has this pendant steric volume, the difference d in this radial distance represents the intermolecular distance provided by the volume. When both dopants have pendant steric volume, the intermolecular distance is roughly equal to the sum of d1+d2, where d1 is the difference in distances between the center of mass of the first dopant and (a) and (b), and d2 is the difference in distances between the center of mass of the second dopant and (a) and (b). To prevent Dexter energy transfer, d or d1+d2 should be greater than More preferably greater than and more preferably greater than

[0083] For secondary NIR emitters where the excited state is a rotated 1 / 2 doublet state, energy transfer to this emitter can proceed via a Dexter or Forster mechanism, since doublet emitters do not undergo the formation of exciton states with spin prohibition. Therefore, doublet emitters can be included in device structures that facilitate Dexter or Forster energy transfer.

[0084] An OLED is disclosed, comprising an anode, a cathode, and a first organic layer disposed between the anode and the cathode. The first organic layer comprises a primary phosphorescent emitter and a first host, and wherein one of the following conditions is true: (1) the first organic layer further comprises a secondary emitter; or (2) the OLED further comprises a second organic layer disposed between the anode and the cathode, wherein the second organic layer comprises a secondary emitter. The peak emission wavelength λmax of the phosphorescent emitter is ≥600 nm and ≤750 nm. The peak emission wavelength λmax of the secondary emitter is ≥750 nm. The lowest excited triplet energy T1 of the first host is at least 0.1 eV higher than the lowest excited triplet energy T1 of the phosphorescent emitter.

[0085] In embodiments where condition (1) is true, the emissive layer comprises at least three components, including a host material, a first transition metal compound (M 1 L 1 n ) of a primary phosphorescent emitter, and a secondary NIR emitter consisting of one of the following: a second transition metal compound (M 2 L 2 n ), an organic fluorophore or an organic doublet emitter. In the case where the secondary NIR emitter is a second transition metal compound, the metal M 2Selected from lanthanide elements. The disclosed OLED is particularly suitable for NIR applications. The primary phosphorescent emitter acting as a sensitizer for the secondary NIR emitter refers to the fact that the primary phosphorescent emitter acts as an exciton formation site to exploit the favorable properties of the phosphorescent OLED stack and allows incorporation into larger OLED-based displays. In the case where the primary phosphorescent emitter and the secondary NIR emitter are co-doped in the EML of the OLED, the energy transfer from the primary phosphorescent emitter sensitizer to the secondary NIR emitter is carried out via a Dexter energy transfer mechanism. In the case where the primary phosphorescent emitter and the secondary NIR emitter are provided in a separate layer, the energy transfer from the primary phosphorescent emitter sensitizer to the secondary NIR emitter is carried out via a Foster energy transfer mechanism and reduces undesired Dexter energy transfer.

[0086] In some embodiments of OLEDs, condition (1) is true, and the first organic layer is the only layer containing a secondary emitter. In some embodiments of OLEDs, condition (2) is true, and the second organic layer is the only layer containing a secondary emitter.

[0087] In some embodiments of the OLED, condition (2) is true and the second organic layer further comprises a second host.

[0088] In some embodiments of OLEDs, the secondary emitter has a peak absorption wavelength λ and the phosphorescent emitter has a peak emission wavelength λ max The peak absorption wavelength λ of the secondary emitter max The difference between them is less than 200 nm.

[0089] In some embodiments of OLEDs, the secondary emitter has a peak absorption wavelength λ and the phosphorescent emitter has a peak emission wavelength λ max The peak absorption wavelength λ of the secondary emitter max The difference between them is less than 150nm.

[0090] In some embodiments, where condition (2) is true, the first organic layer and the second organic layer are separated by one or more additional organic layers. In some embodiments, at least one of the additional organic layers may include a third host. In some embodiments, the first, second, and third hosts may be the same or different from each other.

[0091] In some embodiments, where condition (2) is true and the first organic layer and the second organic layer are separated by one or more additional organic layers, at least one of the additional organic layers comprises a charge transport material. In some embodiments, the spacing between the first organic layer and the second organic layer is ≥1 nm. In some embodiments, the spacing between the first organic layer and the second organic layer is ≥2 nm. In some embodiments, the spacing between the first organic layer and the second organic layer is ≥4 nm. Figure 3An example of such an OLED stack 300 is shown. In OLED stack 300, the first organic layer containing the primary emitter is EML 1 and the second organic layer containing the secondary NIR emitter is EML 2. One or more additional organic layers (such as a charge transport material layer) separating the first organic layer and the second organic layer are shown in OLED stack 300 as Thick TL layer. Figure 3 In the figure, the thickness of EML 1 and EML 2 are marked as To show the maximum thickness For example, in embodiments where the OLED has both EML 1 (containing the primary emitter) and EML 2 (containing the secondary NIR emitter), its thickness will be greater than 0 and at most The thickness of the electron injection layer (EIL), electron transport layer (ETL), hole blocking layer (BL), charge transport layer (TL), and electron blocking layer (EBL) are shown as a thickness range with a low end of the range being "0" because these functional layers are optional layers and in some embodiments of the OLED stack, one or more of these layers are not present. The thickness of the hole transport layer (HTL) ranges from The OLED further comprises a second organic layer comprising a secondary emitter.

[0092] In some embodiments of the OLED, where condition (1) is true, the concentration of the phosphorescent emitter in the first organic layer and the concentration of the secondary emitter are different. In some embodiments, the concentration of the phosphorescent emitter in the first organic layer and the concentration of the secondary emitter are each ≤ 10 wt.%. In some embodiments, the concentration of the phosphorescent emitter in the first organic layer and the concentration of the secondary emitter are each ≤ 5 wt.%. In some embodiments, the concentration of the phosphorescent emitter in the first organic layer and the concentration of the secondary emitter are each ≤ 3 wt.%. In some embodiments, the average intermolecular distance between the phosphorescent emitter and the secondary emitter is ≤ 10 wt.%. In some embodiments, the average intermolecular distance between the phosphorescent emitter and the secondary emitter is In some embodiments, the average intermolecular distance between the phosphorescent emitter and the secondary emitter is

[0093] In some embodiments of OLEDs, the phosphorescent emitter has the formula M 1 L 1 m ; where M1 is selected from the group consisting of: Os, Ir, Pd, Pt, Cu, Ag and Au; wherein L 1 can represent one or more ligands that are the same or different; wherein each L 1 are independently monodentate or polydentate; and wherein m represents a moiety that can coordinate to M 1 Ligand L 1 The maximum possible number.

[0094] In some embodiments of OLEDs, the secondary emitter has the formula 2 L 2 n , where M 2 is selected from the group consisting of lanthanide metals, wherein L 2 represents one or more ligands that are the same or different, wherein each L 2 are independently monodentate or polydentate, and wherein n represents a moiety that can coordinate to M 2 L 2 The maximum possible number of ligands.

[0095] In some embodiments of the OLED, the secondary emitter is selected from the group consisting of a fluorescent emitter, a thermally activated delayed fluorescent emitter, and an emitter containing an unpaired electron in its ground state.

[0096] In some embodiments of OLEDs, wherein the phosphorescent emitter has the formula M as defined above: 1 L 1 m , M 1 In some embodiments, wherein the phosphorescent emitter has a formula M as defined above, 1 L 1 m , the phosphorescent emitter has the formula M 1 (L A ) x (L B ) y (L C ) z ; where L A , L B and L C Each is a bidentate ligand; and wherein x is 1, 2 or 3; y is 0, 1 or 2; z is 0, 1 or 2; and x+y+z is the oxidation state of the metal M.

[0097] In some embodiments of OLEDs, wherein the secondary emitter has the formula M as defined above: 2 L 2 n, the phosphorescent emitter has a minimum triplet energy T1 that is the same as or higher than the emission ff transition energy of the secondary emitter. In some embodiments, M 2 Selected from the group consisting of: Eu, Nd, Yb and Er.

[0098] In some embodiments of OLEDs, wherein the phosphorescent emitter has the formula M as defined above: 1 (L A ) x (L B ) y (L C ) z , the phosphorescent emitter has a formula selected from the group consisting of: Ir(L A )3、Ir(L A )(L B )2、Ir(L A )2(L B )、Ir(L A )2(L C ) and Ir(L A )(L B )(L C ); and where L A , L B and L C Different from each other.

[0099] In some embodiments of OLEDs, wherein the phosphorescent emitter has the formula M as defined above: 1 (L A ) x (L B ) y (L C ) z , the phosphorescent emitter has the formula Pt(L A )(L B ); and where L A and L B Can be the same or different. In some embodiments, L A and L B In some embodiments, L A and L B It is linked at two locations to form a macrocyclic tetradentate ligand.

[0100] In some embodiments of OLEDs, wherein the phosphorescent emitter has the formula M as defined above: 1 (L A ) x (L B ) y (L C ) z , LA , L B and L C Each independently selected from the group consisting of:

[0101]

[0102]

[0103] Where X 1 To X 13 Each is independently selected from the group consisting of carbon and nitrogen; wherein X is selected from the group consisting of: BR', NR', PR', O, S, Se, C=O, S=O, SO2, CR'R", SiR'R" and GeR'R"; wherein R' and R" are optionally fused or joined to form a ring; wherein R a , R b , R c and R d Each may represent a single substitution to the maximum possible number of substitutions, or no substitution; wherein R', R", R a , R b , R c and R d are each independently hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, benzonitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein R a , R b , R c and R d Any two adjacent substituents in are optionally fused or joined to form a ring or to form a multidentate ligand. A and L B Each independently selected from the group consisting of:

[0104]

[0105]

[0106] In some embodiments of the OLED, wherein the secondary emitter is a fluorescent emitter selected from the group consisting of:

[0107]

[0108]

[0109] Where R 1 to R 5Each independently represents a single substitution to the maximum number of substitutions it may have, or no substitution;

[0110] Where R 1 to R 5 each independently is hydrogen or a substituent selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

[0111] Where R 1 to R 5 At least one of them is R.

[0112] In some embodiments of the OLED, wherein the secondary emitter contains an unpaired electron in its ground state, the secondary emitter is selected from the group consisting of:

[0113]

[0114] Where R A , R B , R C , R D and R E Each independently represents monosubstituted to the maximum permissible substitution, or no substitution; and wherein R A , R B , R C , R D and R E Each is independently hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0115] In some embodiments of the OLED, the first host comprises 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. In some embodiments, the first host is selected from the group consisting of:

[0116]

[0117]

[0118] and combinations thereof.

[0119] An OLED is disclosed, comprising an anode, a cathode, and a first organic layer disposed between the anode and the cathode. The first organic layer comprises a first metal complex M 1 L 1 m and the first subject; where one of the following is true:

[0120] (1) The first organic layer further comprises a second metal complex M 2 L 2 n ;or

[0121] (2) The OLED device further comprises a second organic layer disposed between the anode and the cathode, wherein the second organic layer comprises a second metal complex M 2 L 2 n ;

[0122] Among them, M 1 Selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag and Au;

[0123] Among them, M 2 selected from the group consisting of lanthanide metals;

[0124] Where L 1 and L 2 Each is independently a monodentate or polydentate ligand and may represent multiple ligands that are the same or different;

[0125] Where m means it can coordinate to M 1 Ligand L 1 The maximum possible number of

[0126] Where n represents the coordination to M 2 Ligand L 2 The maximum possible number of

[0127] The lowest triplet energy T1 of the first host and the first metal complex M 1 L 1 m The lowest triplet energy T1 of

[0128] The first metal complex M 1 L 1 m The lowest triplet energy T1 of the second metal complex M 2 L 2 n The emission ff transition energy E f-f The same or higher than.

[0129] In some embodiments of OLED, condition (1) is true, and the first organic layer comprises M 2 L 2 n In some embodiments of the OLED, condition (2) is true, and the second organic layer is a layer containing M 2 L 2 n In some embodiments of the OLED, where condition (2) is true, the second organic layer further comprises a host.

[0130] In some embodiments of OLED, M 1 In some embodiments of the OLED, M 2 is selected from the group consisting of: Eu, Nd, Yb and Er. In some embodiments of the OLED, the ligand L 2 The lowest triplet energy T1 of at least one of the first metal complexes M 1 L 1 m The lowest triplet energy T1 of the ligand L is the same as or lower than that of the ligand L. 2 The lowest triplet energy T1 of at least one of the first metal complexes M 1 L 1 m The lowest triplet energy T1 is the same as or higher than that of .

[0131] In some embodiments of OLED, M 2 is Eu. In some embodiments of OLED, M 2 In some embodiments of OLED, M 2 is Nd. In some embodiments of OLEDs, M 2 Yes.

[0132] In some embodiments of OLEDs, the first metal complex M 1 L 1 m With the formula M(L A ) x (L B ) y (L C ) z , where L A , L B and L C Each is a bidentate ligand; and wherein x is 1, 2, or 3; y is 0, 1, or 2; z is 0, 1, or 2; and x+y+z is the oxidation state of metal M. In some embodiments, the first metal complex M 1 L 1m Having a formula selected from the group consisting of: Ir(L A )3、Ir(L A )(L B )2、Ir(L A )2(L B )、Ir(L A )2(L C ) and Ir(L A )(L B )(L C ); and where L A , L B and L C In some embodiments, the first metal complex M 1 L 1 m With the formula Pt(L A )(L B ); and where L A and L B Can be the same or different.

[0133] In some embodiments of OLED, the first metal complex M 1 L 1 m With the formula Pt(L A )(L B ), and where L A and L B Can be the same or different, L A and L B In some embodiments, L A and L B It is linked at two locations to form a macrocyclic tetradentate ligand.

[0134] In some embodiments of OLED, the first metal complex M 1 L 1 m Having a formula selected from the group consisting of: Ir(L A )3、Ir(L A )(L B )2、Ir(L A )2(L B )、Ir(L A )2(L C ) and Ir(L A )(L B )(L C ); and where L A , L B and L C Different from each other, L A , LB and L C Each independently selected from the group consisting of:

[0135]

[0136]

[0137] Each X 1 To X 13 are independently selected from the group consisting of carbon and nitrogen; wherein X is selected from the group consisting of BR', NR', PR', O, S, Se, C=O, S=O, SO2, CR'R", SiR'R" and GeR'R"; wherein R' and R" are optionally fused or joined to form a ring; wherein R a , R b , R c and R d Each may represent a single substitution to the maximum possible number of substitutions, or no substitution; wherein R', R", R a , R b , R c and R d are each independently hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, benzonitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein R a , R b , R c and R d Any two adjacent substituents in are optionally fused or joined to form a ring or to form a multidentate ligand. A and L B Each independently selected from the group consisting of:

[0138]

[0139]

[0140] In some embodiments of OLEDs, the second metal complex M 2 L 2 n Selected from the group consisting of:

[0141]

[0142] wherein rings A, B and C are each independently a 5-membered or 6-membered carbocyclic or heterocyclic ring; wherein R A, R B , R C , R D , R E and R F It can represent single substitution to the maximum possible substitution, or no substitution; where R A , R B , R C , R D , R E and R F are each independently hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, benzonitrile, isonitrile, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein L 3 and L 4 Each is independently selected from a direct bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof.

[0143] In some embodiments of OLEDs, the second metal complex M 2 L 2 n Selected from the group consisting of:

[0144]

[0145]

[0146]

[0147] In some embodiments of the OLED, the first host comprises 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.

[0148] In some embodiments of the OLED, the first host is selected from the group consisting of:

[0149]

[0150]

[0151] and combinations thereof.

[0152] Sensitizing another secondary emitter (such as a fluorescent or lanthanide emitter) with a phosphorescent emitter provides a method for obtaining higher efficiency from a secondary emitter while retaining its emission characteristics. However, we predict specific benefits for applying this device structure to the near-infrared emission region. For the near-infrared, secondary emitters allow device efficiency to be improved due to the shorter transient lifetimes provided by these emitters. Because the energy gap law predicts that the non-radiative rate increases exponentially as the excited state is reduced to the ground state (emission) energy gap, effective NIR emission requires extremely fast emission rates to compete with the faster non-radiative decay in this system. Therefore, it is expected that the use of secondary emitters (such as fluorophores) with faster emission rates will result in higher efficiencies than both all-phosphorescent devices and all-fluorescent devices, the all-phosphorescent devices having long excited state lifetimes, and the all-fluorescent devices having lower emission quantum yields due to wasted triplet excitons.

[0153] The standard measurement of peak wavelength (λmax) is as follows: Photoluminescence is measured by photoexciting thin film samples of the emitter doped at 1% (wt. %) in an inert poly(methyl methacrylate) matrix.

[0154] In some embodiments, the OLED has one or more features selected from the group consisting of: flexible, rollable, foldable, stretchable, and bendable. In some embodiments, the OLED is transparent or translucent. In some embodiments, the OLED further comprises a layer comprising carbon nanotubes.

[0155] In some embodiments, the OLED further comprises a layer comprising a delayed fluorescent emitter. In some embodiments, the OLED comprises an RGB pixel arrangement or a white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a handheld device, or a wearable device. In some embodiments, the OLED is a display panel having a diagonal of less than 10 inches or an area of ​​less than 50 square inches. In some embodiments, the OLED is a display panel having a diagonal of at least 10 inches or an area of ​​at least 50 square inches. In some embodiments, the OLED is a lighting panel.

[0156] Also disclosed is an emissive region in an OLED, wherein the emissive region comprises the first organic layer described herein.

[0157] In some embodiments, the compound can be an emissive dopant. In some embodiments, the compound can generate emission via phosphorescence, fluorescence, thermally activated delayed fluorescence (i.e., TADF, also known as E-type delayed fluorescence, see, e.g., U.S. Application No. 15 / 700,352, which is incorporated herein by reference in its entirety), triplet-triplet annihilation, or a combination of these processes.

[0158] According to another aspect, a formulation comprising a compound described herein is also disclosed.

[0159] The OLEDs disclosed herein may be incorporated into one or more of consumer products, electronic component modules, and lighting panels.The organic layer may be an emissive layer, and the compound may be an emissive dopant in some embodiments, while the compound may be a non-emissive dopant in other embodiments.

[0160] The organic layer may also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the host used may be a) bipolar, b) electron transport, c) hole transport, or d) wide bandgap material that plays a minimal role in charge transport. In some embodiments, the host may include a metal complex. The host may be a triphenylene containing a benzo-fused thiophene or a benzo-fused furan. Any substituent in the host may be a non-fused substituent independently selected from the group consisting of: C n H 2n+1 , OC n H 2n+1 、OAr1、N(C n H 2n+1 )2, N(Ar1)(Ar2), CH=CH-C n H 2n+1 、C≡CC n H 2n+1 , Ar1, Ar1-Ar2 and C n H 2n -Ar1, or the host is unsubstituted. In the aforementioned substituents, n may be in the range of 1 to 10; and Ar1 and Ar2 may be independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole and heteroaromatic analogs thereof. The host may be an inorganic compound. For example, an inorganic material containing Zn, such as ZnS.

[0161] The host may be a compound 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. The host may include a metal complex. The host may be, but is not limited to, a specific compound selected from the group consisting of:

[0162]

[0163]

[0164]

[0165] and combinations thereof.

[0166] The following provides additional information about possible subjects.

[0167] In another aspect of the present invention, a formulation comprising the novel compounds disclosed herein is described. The formulation may include one or more components disclosed herein selected from the group consisting of: a solvent, a host, a hole injection material, a hole transport material, an electron blocking material, a hole blocking material, and an electron transport material.

[0168] Combination with other materials

[0169] The materials described herein as being suitable for use in a particular layer in an organic light-emitting device can be used in combination with a 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, barrier layers, injection layers, electrodes, and other layers that may be present. The materials described or mentioned below are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0170] Conductive dopants:

[0171] The charge transport layer can be doped with a conductivity dopant to substantially change its charge carrier density, which in turn will change its conductivity. The conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor can also be achieved. The hole transport layer can be doped with a p-type conductivity dopant, and an n-type conductivity dopant is used in the electron transport layer.

[0172] Non-limiting examples of conductive dopants that can be used in OLEDs in combination with the materials disclosed herein are exemplified below, along with references disclosing those materials: EP01617493, EP01968131, EP2020694, EP2684932, US20050139810, US20070160905, US20090167167, US2010288362, WO06081780, WO2009003455, WO2009008277, WO2009011327, WO2014009310, US2007252140, US2015060804, US20150123047, and US2012146012.

[0173]

[0174] HIL / HTL:

[0175] The hole injection / transport material used in the present invention is not particularly limited, and any compound can be used as long as the compound is generally used as a hole injection / transport material. Examples of the material include (but are not limited to): phthalocyanine or porphyrin derivatives; aromatic amine derivatives; indolecarbazole derivatives; polymers containing fluorocarbons; polymers having conductive dopants; conductive polymers such as PEDOT / PSS; self-assembling monomers derived from compounds such as phosphonic acid and silane derivatives; metal oxide derivatives such as MoO x ; p-type semiconductive organic compounds, such as 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile; metal complexes; and crosslinkable compounds.

[0176] Examples of aromatic amine derivatives for use in HIL or HTL include, but are not limited to, the following general structure:

[0177]

[0178] Ar 1 To Ar 9 Each of the following is selected from the group consisting of aromatic hydrocarbon cyclic compounds: benzene, biphenyl, terphenyl, triphenylene, naphthalene, anthracene, phenanthrene, fluorene, pyrene, Perylene and azulene; a group consisting of 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, naphthridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuranopyridine, furanodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine; and a group consisting of 2 to 10 cyclic structural units, which are groups of the same type or different types selected from aromatic hydrocarbon ring groups and aromatic heterocyclic groups and are directly or via at least one of oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, phosphorus atoms, boron atoms, chain structural units and aliphatic ring groups. Each Ar may be unsubstituted or substituted with a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0179] In one aspect, Ar1 To Ar 9 Independently selected from the group consisting of:

[0180]

[0181] Where k is an integer from 1 to 20; X 101 To X 108 is C (including CH) or N; Z 101 It is NAr 1 , O or S; Ar 1 Having the same groups as defined above.

[0182] Examples of metal complexes used in HIL or HTL include, but are not limited to, the following general formula:

[0183]

[0184] Where Met is a metal with an atomic weight greater than 40; (Y 101 -Y 102 ) is a bidentate ligand, Y 101 and Y 102 is independently selected from C, N, O, P and S; L 101 is an auxiliary ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal; and k'+k" is the maximum number of ligands that can be attached to the metal.

[0185] In one aspect, (Y 101 -Y 102 ) is a 2-phenylpyridine derivative. In another aspect, (Y 101 -Y 102 ) is a carbene ligand. In another aspect, Met is selected from Ir, Pt, Os and Zn. In another aspect, the metal complex has a relative + / Fc coupling is less than the minimum oxidation potential in solution of about 0.6 V.

[0186] Non-limiting examples of HIL and HTL materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below, along with references disclosing those materials: CN102702075, DE102012005215, EP01624500, EP01698613, EP01806334, EP01930964, EP01972613, EP01997799, EP02011790, EP02055700, EP02055701, EP1725079, EP2085382, EP2660300, EP650955, JP07-073529, JP2005112765, J P2007091719, JP2008021687, JP2014-009196, KR20110088898, KR2013007 7473, TW201139402, US06517957, US20020158242, US20030162053, US2005 0123751, US20060182993, US20060240279, US20070145888, US2007018187 4. US20070278938, US20080014464, US20080091025, US20080106190, US200 80124572, US20080145707, US20080220265, US20080233434, US20080303417, US2008107919, US20090115320, US20090167161, US2009066235, US201 1007385, US20110163302, US2011240968, US2011278551, US2012205642, US2013241401, US20140117329, US2014183517, US5061569, US5639914, WO0 5075451, WO07125714, WO08023550, WO08023759, WO2009145016, WO2010061824, WO2011075644, WO2012177006, WO2013018530, WO2013039073, WO201 3087142, WO2013118812, WO2013120577, WO2013157367, WO2013175747, WO 2014002873, WO2014015935, WO2014015937, WO2014030872, WO2014030921,WO2014034791, WO2014104514, WO2014157018. ,

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194] EBL:

[0195] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons that leave the emissive layer. The presence of such a blocking layer in a device can produce substantially higher efficiency and / or longer lifetime than a similar device lacking a blocking layer. In addition, a blocking layer can be used to confine emission to desired areas of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a 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 a 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 used in one of the hosts described below.

[0196] main body:

[0197] 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 greater than the triplet energy of the dopant. Any host material may be used with any dopant as long as the triplet criterion is satisfied.

[0198] Examples of metal complexes used as hosts preferably have the following general formula:

[0199]

[0200] Where Met is a metal; (Y 103 -Y 104) is a bidentate ligand, Y 103 and Y 104 is independently selected from C, N, O, P and S; L 101 is another ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal; and k'+k" is the maximum number of ligands that can be attached to the metal.

[0201] In one aspect, the metal complex is:

[0202]

[0203] where (ON) is a bidentate ligand with a metal coordinated to O and N atoms.

[0204] In another aspect, Met is selected from Ir and Pt. In another aspect, (Y 103 -Y 104 ) is a carbene ligand.

[0205] In one aspect, the host compound contains at least one selected from the group consisting of benzene, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthrene, fluorene, pyrene, Perylene and azulene; a group consisting of 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, naphthridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuranopyridine, furanodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine; and a group consisting of 2 to 10 cyclic structural units, which are groups of the same type or different types selected from aromatic hydrocarbon ring groups and aromatic heterocyclic groups and are directly or via at least one of oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, phosphorus atoms, boron atoms, chain structural units and aliphatic ring groups. Each option in each group may be unsubstituted or substituted with a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0206] In one aspect, the subject compound contains at least one of the following groups in the molecule:

[0207]

[0208]

[0209] Where R 101 is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino and combinations thereof, and when it is aryl or heteroaryl, it has a similar definition to Ar mentioned above. k is an integer from 0 to 20 or from 1 to 20. X 101 To X 108 Z is independently selected from C (including CH) or N. 101 and Z 102 Independently selected from NR 101 , O or S.

[0210] Non-limiting examples of host materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below, along with references disclosing those materials: EP2034538, EP2034538A, EP2757608, JP2007254297, KR20100079458, KR20120088644, KR20120129733, KR20130115564, TW201329200, US20030175553, US20050238919, US20060280965, US2009 0017330, US20090030202, US20090167162, US20090302743, US20090309488, US20100012931, US20100084966, US20100187984, US2010187984, US2012075273, US2012126221, US2013009543, US2013105787, US2013175519, US2014001446, US20140183503, U S20140225088, US2014034914, US7154114, WO2001039234, WO2004093207, WO2005014551, WO2005089025, WO2006072002, WO200 6114966, WO2007063754, WO2008056746, WO2009003898, WO2009021126, WO2009063833, WO2009066778, WO2009066779, WO20090 86028, WO2010056066, WO2010107244, WO2011081423, WO2011081431, WO2011086863, WO2012128298, WO2012133644, WO2012133 649. WO2013024872, WO2013035275, WO2013081315, WO2013191404, WO2014142472, US20170263869, US20160163995, US9466803,

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217] Other emitters:

[0218] One or more other emitter dopants may be used in combination with the compounds of the present invention. Examples of other emitter dopants are not particularly limited, and any compound may be used as long as the compound is commonly used as an emitter material. Examples of suitable emitter materials include, but are not limited to, compounds that can produce emission via phosphorescence, fluorescence, thermally activated delayed fluorescence (i.e., TADF, also known as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes.

[0219] Non-limiting examples of emitter materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below, along with references disclosing those materials: CN103694277, CN1696137, EB01238981, EP01239526, EP01961743, EP1239526, EP1244155, EP1642951, EP1647554, EP1841834, EP1841834B, EP2062907, EP2730583, JP2012074444, JP201310263, JP4478555, KR1020090133652, KR20120090133653. 32054, KR20130043460, TW201332980, US06699599, US06916554, US200100 19782, US20020034656, US20030068526, US20030072964, US20030138657, U U.S. 20060202194, US20060251923, US20070034863, US20070087321, US200701 03060, US20070111026, US20070190359, US20070231600, US2007034863, US 2007104979, US2007104980, US2007138437, US2007224450, US2007278936 , US20080020237, US20080233410, US20080261076, US20080297033, US2008 05851, US2008161567, US2008210930, US20090039776, US20090108737, US 20090115322, US20090179555, US2009085476, US2009104472, US201000905 91. US20100148663, US20100244004, US20100295032, US2010102716, US20 10105902, 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。、

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226] HBL:

[0227] A hole blocking layer (HBL) can be used to reduce the number of holes and / or excitons that leave the emissive layer. The presence of such a blocking layer in a device can result in substantially higher efficiency and / or longer lifetime than a similar device lacking a blocking layer. In addition, a blocking layer can be used to confine emission to a desired area of ​​the OLED. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than one or more of the hosts closest to the HBL interface.

[0228] In one aspect, the compounds used in HBL contain the same molecules or the same functional groups as used in the subjects described above.

[0229] In another aspect, the compound used in HBL contains at least one of the following groups in the molecule:

[0230]

[0231] Where k is an integer from 1 to 20; L 101 is another ligand, and k' is an integer from 1 to 3.

[0232] ETL:

[0233] The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped. Doping may 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 generally used to transport electrons.

[0234] In one aspect, the compound used in the ETL contains at least one of the following groups in the molecule:

[0235]

[0236] Where R 101is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino and combinations thereof, and when it is aryl or heteroaryl, it has a similar definition to Ar above. Ar 1 To Ar 3 has a similar definition to Ar mentioned above. k is an integer from 1 to 20. 101 To X 108 is selected from C (including CH) or N.

[0237] In another aspect, the metal complex used in the ETL contains (but is not limited to) the following general formula:

[0238]

[0239] wherein (ON) or (NN) is a bidentate ligand having a metal coordinated to atoms O, N or N, N; L 101 is another ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal.

[0240] Non-limiting examples of ETL materials that can be used in OLEDs in combination with the materials disclosed herein are exemplified below, along with references disclosing those materials: CN103508940, EP01602648, EP01734038, EP01956007, JP2004-022334, JP2005149918, JP2005-268199, KR0117693, KR20130108183, US20040036077, US20070104977, US2007018155, US20090101870, US20090115316, US20090140637, US20090179554, US2009218940, and US2009018957. 10108990, US2011156017, US2011210320, US2012193612, US2012214993, US201401 4925, US2014014927, US20140284580, US6656612, US8415031, WO2003060956, WO20 07111263, WO2009148269, WO2010067894, WO2010072300, WO2011074770, WO201110 5373, WO2013079217, WO2013145667, WO2013180376, WO2014104499, WO2014104535,

[0241]

[0242]

[0243]

[0244] Charge Generation Layer (CGL)

[0245] In a tandem or stacked OLED, the CGL plays a fundamental role in the performance and consists of an n-doped layer and a p-doped layer for injecting electrons and holes, respectively. Electrons and holes are supplied by the CGL and electrodes. The electrons and holes consumed in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; then, the bipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductivity dopants used in the transport layer.

[0246] In any of the above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms may be partially or fully deuterated. Thus, any specific listed substituents, such as (but not limited to) methyl, phenyl, pyridyl, etc., may be in their non-deuterated, partially deuterated, and fully deuterated forms. Similarly, substituent classes (such as (but not limited to) alkyl, aryl, cycloalkyl, heteroaryl, etc.) may also be in their non-deuterated, partially deuterated, and fully deuterated forms.

[0247] It should be understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the present invention. For example, other materials and structures may be used to replace many materials and structures described herein without departing from the spirit of the present invention. The present invention as required may therefore include variations of specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that the various theories about why the present invention works are not intended to be restrictive.

Claims

1. An organic light emitting device (OLED), comprising: anode; cathode; a first organic layer disposed between the anode and the cathode; wherein the first organic layer comprises a primary phosphorescent emitter and a first host; One of the following conditions is true: (1) the first organic layer further comprises a secondary emitter; or (2) the OLED device further comprises a second organic layer disposed between the anode and the cathode, wherein the second organic layer comprises a secondary emitter; wherein the primary phosphorescent emitter has the formula M 1 (L A ) x (L B ) y (L C ) z ; Where L A , L B and L C Each is a bidentate ligand; Among them, M 1 is selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag, and Au; and wherein x is 1, 2 or 3; y is 0, 1 or 2; z is 0, 1 or 2; and x+y+z is the metal M 1 oxidation state; Where L A Selected from the group consisting of: Where L B and L C Each independently selected from the group consisting of: in, Each X 1 To X 10 independently selected from the group consisting of C and N; X 1 To X 10 At least one of them is N; X is selected from the group consisting of BR', NR', PR', O, S, Se, C=O, S=O, SO2, CR'R", SiR'R", and GeR'R"; R' and R" are optionally fused or joined to form a ring; R', R", R a , R b and R c Each can represent a single substitution to the maximum possible number of substitutions or no substitution; R', R", R a , R b and R c each independently is hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, benzonitrile, isonitrile, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; and R a , R b and R c Any two adjacent substituents of are optionally fused or joined to form a ring or to form a multidentate ligand; wherein the peak emission wavelength λmax of the primary phosphorescent emitter is ≥600nm and ≤750nm; wherein the secondary emitter is a near-infrared emitter having a peak emission wavelength λmax between 750nm and 2500nm; wherein the lowest excited state triplet energy T1 of the first host is at least 0.1 eV higher than the lowest excited state triplet energy T1 of the primary phosphorescent emitter; wherein the secondary emitter is selected from the group consisting of a fluorescent emitter, a thermally activated delayed fluorescent emitter, and an emitter containing an unpaired electron in its ground state; Therein, Dexter energy transfer from the primary emitter to the secondary emitter is minimized, thereby preventing the formation of fluorophore triplet excitons. 2 . The OLED according to claim 1 , wherein the condition (1) is true and the first organic layer is the only layer containing the secondary emitter.

3. The OLED according to claim 1, wherein the condition (2) is true and the second organic layer is the only layer containing the secondary emitter.

4. The OLED of claim 1 , wherein the secondary emitter has a peak absorption wavelength λ max The peak absorption wavelength λ of the secondary emitter max The difference between them is less than 200 nm. 5 . The OLED of claim 1 , wherein the first organic layer and the second organic layer are separated by one or more additional organic layers. The OLED according to claim 5 , wherein a distance between the first organic layer and the second organic layer is ≥1 nm.

7. The OLED of claim 1, wherein the condition (1) is true, and wherein the concentration of the primary phosphorescent emitter and the concentration of the secondary emitter in the first organic layer are different.

8. The OLED according to claim 1, wherein the condition (1) is true, and wherein the concentration of the primary phosphorescent emitter and the concentration of the secondary emitter in the first organic layer are each ≤ 10 wt.%.

9. The OLED according to claim 1, wherein the condition (1) is true, and wherein the average intermolecular distance between the primary phosphorescent emitter and the secondary emitter is ≥ 10. The OLED of claim 1, wherein the condition (2) is true, wherein the primary emitter and the secondary emitter are spatially isolated, thereby minimizing any Dexter energy transfer and preventing the formation of fluorophore triplet excitons.

11. The OLED of claim 10, wherein the first organic layer and the second organic layer are separated by one or more layers of host or transport material to achieve an interlayer separation distance greater than 1 nm.

12. The OLED of claim 1, wherein the condition (1) is true and the primary and secondary emitters are arranged to result in a donor-acceptor radius r greater than The doping concentration of is doped in the first organic layer, and the donor-acceptor radius r is the distance between the aromatic π systems of two emitters.

13. A consumer product comprising an OLED, the OLED comprising: anode; cathode; a first organic layer disposed between the anode and the cathode; wherein the first organic layer comprises a primary phosphorescent emitter and a first host; One of the following conditions is true: (1) the first organic layer further comprises a secondary emitter; or (2) the OLED device further comprises a second organic layer disposed between the anode and the cathode, wherein the second organic layer comprises a secondary emitter; wherein the primary phosphorescent emitter has the formula M 1 (L A ) x (L B ) y (L C ) z ; Where L A , L B and L C Each is a bidentate ligand; Among them, M 1 is selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag, and Au; and wherein x is 1, 2 or 3; y is 0, 1 or 2; z is 0, 1 or 2; and x+y+z is the metal M 1 oxidation state; Where L A Selected from the group consisting of: Where L B and L C Each independently selected from the group consisting of: in, Each X 1 To X 10 independently selected from the group consisting of C and N; X 1 To X 10 At least one of them is N; X is selected from the group consisting of BR', NR', PR', O, S, Se, C=O, S=O, SO2, CR'R", SiR'R", and GeR'R"; R' and R" are optionally fused or joined to form a ring; R', R", R a , R b and R c Each can represent a single substitution to the maximum possible number of substitutions or no substitution; R', R", R a , R b and R c each independently is hydrogen or a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, benzonitrile, isonitrile, thiol, sulfinyl, sulfonyl, phosphino, and combinations thereof; and R a , R b and R c Any two adjacent substituents of are optionally fused or joined to form a ring or to form a multidentate ligand; wherein the peak emission wavelength λmax of the primary phosphorescent emitter is ≥600nm and ≤750nm; wherein the secondary emitter is a near-infrared emitter having a peak emission wavelength λmax between 750nm and 2500nm; wherein the lowest excited state triplet energy T1 of the first host is at least 0.1 eV higher than the lowest excited state triplet energy T1 of the primary phosphorescent emitter; wherein the secondary emitter is selected from the group consisting of a fluorescent emitter, a thermally activated delayed fluorescent emitter, and an emitter containing an unpaired electron in its ground state; Therein, Dexter energy transfer from the primary emitter to the secondary emitter is minimized, thereby preventing the formation of fluorophore triplet excitons.

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