KR102315298B1 - Material for phosphorescent light-emitting element - Google Patents

Abstract

A composition formed from a mixture of dopant and host material having comparable thermal deposition properties is disclosed that is pre-mixed in a deposition source that can be used to co-deposit the material into a phosphorescent emissive layer via a vacuum thermal deposition process.

Description

MATERIAL FOR PHOSPHORESCENT LIGHT-EMITTING ELEMENT

The present invention relates to an organometallic phosphorescent dopant/organic host compound material combination that can be advantageously used in an organic light emitting device, and a method for manufacturing an organic light emitting device containing the organometallic phosphorescent dopant/host compound material combination. More specifically, the present invention relates to a premix comprising an organic host compound and an organometallic phosphorescent dopant deposited to provide an organic thin film having a very constant host:dopant ratio. The uniformity of the deposited pre-mixed thin films allows for reliable performance results and sophisticated optimization of material parameters in relation to the devices using them.

Optoelectronic devices using organic materials are becoming increasingly important for several reasons. Many of the materials used to fabricate such devices are relatively inexpensive, so organic optoelectronic devices have the potential for economic advantages over inorganic devices. In addition, the intrinsic properties of organic materials, such as their flexibility, make them well suited for certain applications, such as fabrication on flexible substrates. Examples of the organic optoelectronic device include an organic light emitting device (OLED), an organic phototransistor, an organic photovoltaic cell, and an organic photodetector. For OLEDs, organic materials can have performance advantages over conventional materials. For example, the wavelength at which the organic light emitting layer emits light can generally be easily tuned with suitable dopants.

OLED uses an organic thin film that emits light when a voltage is applied to the device. OLEDs are an increasingly important technology for use in applications such as flat panel displays, lighting and backlighting. Various OLED materials and structures are described in US Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emitting molecules is full color displays. The industry standard for such displays requires pixels tuned to emit a specific color, referred to as a “saturated” color. In particular, this criterion requires saturated red, green and blue pixels. Color can be measured using CIE coordinates known in the art.

An example of a green light-emitting molecule is tris(2-phenylpyridine) iridium represented by _{Ir(ppy) 3 having the formula:}

In this formula herein and in the formula below, Applicants depict the coordinate bond from the nitrogen to the metal (here Ir) as a straight line.

As used herein, the term “organic” includes small molecule organic materials as well as polymeric materials that can be used to fabricate organic optoelectronic devices. “Small molecule” refers to any organic material that is not a polymer, and a “small molecule” may actually be quite large. Small molecules may, in some circumstances, contain repeating units. For example, using a long chain alkyl group as a substituent does not remove the molecule from the "small molecule" class. Small molecules may also be incorporated into polymers, for example as side chain groups on the polymer backbone or as part of the backbone. Small molecules can also act as the core portion of a dendrimer consisting of a series of chemical shells created on the core portion. The core portion of the dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a "small molecule" and it has been found that all dendrimers commonly used in the field of OLEDs are small molecules.

As used herein, “top” means furthest from the substrate, and “bottom” means closest to the substrate. When a first layer is described as “disposed on top of” a second layer, the first layer is disposed away from the substrate. Other layers may exist between the first layer and the second layer unless the first layer is specified as being “in contact” with the second layer. For example, the cathode may be described as “disposed on top of” the anode, although there may be various organic layers between the cathode and the anode.

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

A ligand may be referred to as “photoactive” if it is found that the ligand directly contributes to the photoactive properties of the luminescent material. Although the auxiliary ligand may alter the properties of the photoactive ligand, a ligand may be referred to as “auxiliary” if it is found that the ligand does not contribute to the photoactive properties of the luminescent material.

As used herein and as generally understood by one of ordinary skill in the art, if the first "highest occupied molecular orbital" (HOMO) or "least unoccupied molecular orbital" (LUMO) energy level is close to the vacuum energy level, The first energy level is “greater than” or “higher” than the second HOMO or LUMO. Since the ionization potential (IP) is measured as negative energy relative to the vacuum level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (IP is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (the negative value of EA is smaller). In a conventional energy level diagram with a vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level indicates that it is closer to the top of the diagram than a “lower” HOMO or LUMO energy level.

As used herein and as generally understood by one of ordinary skill in the art, the first work function is "greater than" or "higher" than the second work function if the absolute value of the first work function is greater. . Since the work function is usually measured as a negative number with respect to the vacuum level, this means that the negative value of the "higher" work function is greater. In a typical energy level diagram with a vacuum level at the top, the “higher” work function is shown as further down from the vacuum level. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.

Details and the foregoing definitions for OLEDs can be found in US Pat. No. 7,279,704, the disclosure of which is incorporated herein by reference in its entirety.

Summary of the invention

There is provided an organic light emitting device comprising a material combination and a light emitting layer thereof including the material combination. The material combinations include pre-mixed materials suitable for co-deposition. The pre-mixed material comprises a physical mixture of a first compound and a second compound, wherein the first compound is an organometallic phosphorescent dopant compound having the formula:

L ₂ MX, LL'MX, LL'L"M, or LMXX', wherein L, L', L", X, and X' are non-equivalent bidentate ligands, and M has an atomic weight greater than 40 wherein L, L', and L" are ^{monoanionic inequivalent bidentate ligands coordinated to M through sp 2} hybridized carbon, and the organometallic phosphorescent dopant compound is organometallic platinum compound, an organometallic iridium compound and an organometallic osmium compound, wherein the organometallic platinum compound, the iridium compound and the osmium compound optionally include an aromatic ligand, and the second compound is an organic heteroaromatic having the following formula (1) Host compounds include:

<Formula 1>

In the above formula,

Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings.

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (1a):

<Formula 1a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (1b),

<Formula 1b>

Ring B is a heterocyclic ring represented by the formula (1c),

<Formula 1c>

Rings A and B are each fused with an adjacent ring;

Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

when R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring;

m means 0 or an integer of 1 to 2,

n means an integer of 0 or 1. X ¹ is 0 or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic heterocyclic group of 3 to 50 carbon atoms or 6 to 50 carbon atoms excluding groups having more than 5 condensed rings. of an aromatic hydrocarbon group.

X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group.

1 shows an organic light emitting device.
2 shows an inverted organic light emitting device having no separate electron transport layer.

Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes into the organic layer(s) and the cathode injects electrons. The injected holes and electrons move toward oppositely charged electrodes, respectively. When electrons and holes are localized on the same molecule, “excitons,” which are localized electron-hole pairs with excited energy states, are formed. Light is emitted when the exciton is relaxed by a photoluminescence mechanism. In some cases, excitons may be localized on excimers or exciplexes. Non-radiative mechanisms such as thermal relaxation may also occur, but are generally considered undesirable.

Early OLEDs used luminescent molecules that emit light (“fluorescence”) from a singlet state, as disclosed, for example, in US Pat. No. 4,769,292, which is incorporated herein by reference in its entirety. Fluorescence emission generally occurs in time periods of less than 10 nanoseconds.

More recently, OLEDs with emissive materials that emit light from the triplet state (“phosphorescence”) have been illustrated. See 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, No. 3, 4-6 (1999) (“Baldo-II”), which is incorporated herein by reference in its entirety. Phosphorescence is described more specifically at columns 5-6 of US Pat. No. 7,279,704, which is incorporated by reference.

1 shows an organic light emitting device 100 . The drawings are not necessarily drawn to scale. The device 100 includes a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, a light emitting layer 135, a hole blocking layer 140, an electron transport layer ( 145 ), an electron injection layer 150 , a protective layer 155 , a cathode 160 , and a blocking layer 170 . Cathode 160 is a compound cathode having a first conductive layer 162 and a second conductive layer 164 . Device 100 may be fabricated by depositing the layers in the order described. The properties and functions of these various layers, as well as exemplary materials, are more specifically described in US Pat. No. 7,279,704 at columns 6-10, which is incorporated by reference.

More examples of each of these layers are also available. For example, flexible and transparent substrate-anode combinations are disclosed in US Pat. No. 5,844,363, which is incorporated herein by reference in its entirety. _{An example of a p-doped hole transport layer is m-MTDATA doped with F 4} -TCNQ in a molar ratio of 50:1, as disclosed in US Patent Application Publication No. 2003/0230980, which is incorporated herein by reference in its entirety. is incorporated by reference. Examples of luminescent and host materials are disclosed in US Pat. No. 6,303,238 to Thompson et al., which is incorporated herein by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li in a molar ratio of 1:1, as disclosed in US Patent Application Publication No. 2003/0230980, which is incorporated herein by reference in its entirety. . U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entirety, provide examples of cathodes, including compound cathodes having thin layers of metals such as Mg:Ag with laminated transparent, electrically conductive sputter-deposited ITO layers. has been disclosed. The theory and use of barrier layers are more specifically described in US Pat. No. 6,097,147 and US Patent Application Publication No. 2003/0230980, which are incorporated herein by reference in their entirety. An example of an injection layer is provided in US Patent Application Publication No. 2004/0174116, which is incorporated herein by reference in its entirety. A description of the protective layer can be found in US Patent Application Publication No. 2004/0174116, which is incorporated herein by reference in its entirety.

2 shows an inverted OLED 200 . The device includes a substrate 210 , a cathode 215 , a light emitting layer 220 , a hole transport layer 225 and an anode 230 . Device 200 may be fabricated by depositing the layers in the order described. Device 200 may be referred to as an "inverted" OLED, as the most common OLED structure has the cathode disposed above the anode and device 200 has the cathode 215 disposed below the anode 230. Materials similar to those described with respect to device 100 may be used for that layer of device 200 . 2 provides an example of how far some layers may be omitted from the structure of device 100 .

The simple stacked structures shown in Figures 1 and 2 are provided by way of non-limiting example, and it should be understood that embodiments of the present invention may be used in connection with a variety of other structures. The specific materials and structures described are illustrative in nature, and other materials and structures may be used. A functional OLED may be achieved by combining the various layers described in different ways, or layers may be omitted entirely based on design, performance and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described layers may be used. Although many of the examples provided herein describe various layers as comprising a single material, a mixture of materials, such as a host and a dopant, or more generally a mixture may be used. A layer may also have multiple sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in the device 200 , the hole transport layer 225 transports holes and injects holes into the light emitting layer 220 , and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer or may further comprise a plurality of layers of different organic materials, for example as described in connection with FIGS. 1 and 2 .

Structures and materials not specifically described may be used, such as OLEDs comprising polymeric materials (PLEDs) as described in US Pat. No. 5,247,190 to Friend et al., which is incorporated herein by reference in its entirety. Included. As a further example, it is possible to use an OLED having a single organic layer. OLEDs may be stacked, for example, as described in US Pat. No. 5,707,745 to Forrest et al., which is incorporated herein by reference in its entirety. The OLED structure may deviate from the simple stacked structure shown in FIGS. 1 and 2 . For example, the substrate may have a mesa structure as described in US Pat. No. 6,091,195 (Forrest et al.) and/or a pit structure as described in US Pat. No. 5,834,893 (Bulovic et al.) and may include angled reflective surfaces to improve out-coupling, these patents being incorporated herein by reference in their entirety.

Unless otherwise indicated, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layer, preferred methods include thermal evaporation as described in US Pat. Nos. 6,013,982 and 6,087,196, which are incorporated herein by reference in their entirety, ink-jet, US Pat. al.), which is incorporated herein by reference in its entirety, in organic vapor phase deposition (OVPD), U.S. Patent Application Serial No. 7,431,968, which is incorporated herein by reference in its entirety. deposition by organic vapor jet printing (OVJP) as described. Other suitable deposition methods include spin coating and other solution-based processes. The solution-based process is preferably carried out in nitrogen or in an inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred pattern formation methods include deposition through a mask, cold welding as described in US Pat. pattern formation associated with the method. A material to be deposited may be modified to be compatible with a specific deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, preferably containing three or more carbons, can be used on small molecules to enhance their ability to handle solution processing. Substituents having 20 or more carbons may be used, with 3 to 20 carbons being the preferred range. Materials with an asymmetric structure may have better solution processability than those with a symmetric structure, since asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents can be used to enhance the ability of small molecules to handle solution processing.

Devices made in accordance with embodiments of the present invention may include flat panel displays, computer monitors, televisions, billboards, lights for indoor or outdoor lighting and/or signaling, heads-up displays, fully transparent displays, laser printers, telephones, cell phones, tablets , personal digital assistants (PDAs), laptop computers, 3-D displays, digital cameras, camcorders, viewfinders, micro-displays, vehicles, large walls, theater or stadium screens, or a wide variety of consumer products including signage. can be introduced into A variety of control mechanisms, including passive and active matrices, can be used to control devices fabricated in accordance with the present invention. Many of the devices are intended for use in a temperature range conducive to human comfort, such as 18° C. to 30° C., more preferably room temperature (20° C. to 25° C.).

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

The terms halo, halogen, alkyl, cycloalkyl, alkenyl, alkynyl, arylalkyl, heterocyclic group, aryl, aromatic group, and heteroaryl are known in the art and are described in US 7,279,704 at columns 31-32 defined, which is incorporated herein by reference.

Herein, combinations of organometallic phosphorescent dopants and heteroaromatic host compounds can be advantageously used in organic light emitting devices to provide improved performance and improved device products. In particular, devices can be fabricated by co-deposition or premix-deposition with a high degree of uniformity. High performance liquid chromatography (HPLC) results on an exemplary material show a constant ratio of host compound and organometallic phosphorescent dopant from the deposited film. The deposited mixed material films disclosed herein can be used in the emissive layer of phosphorescent OLEDs.

The premixing and deposition of a host material and a luminescent dopant material has been previously reported in the literature. See EP1156536. It is also known to select two or more materials with similar thermal properties for pre-mix deposition. See, for example, US Pat. No. 5,981,092 and PCT/US2004/002710. It would be desirable to have a convenient and consistent way of evaporating the dopant and host material simultaneously. In a phosphorescent OLED, the light emitting layer is usually a host:dopant layer comprising a host compound and an organometallic dopant compound used as a light emitting material. The host significantly affects device voltage, efficiency, and lifetime. Device performance may be further enhanced by the presence of additional carefully selected materials such as assisting dopants in the emissive layer. See, for example, US20040258956 and US20070247061.

When two or more materials are deposited, the simultaneous deposition of individual materials from their respective sources is the most commonly used method, hereinafter referred to as co-deposition. Co-deposition control can be difficult, and deposition equipment is required to have more individually controlled and monitored sources. Accordingly, it may be desirable to deposit a mixture of materials from a single source by a method known as premix-deposition. It may be desirable for the pre-mix mixture to be uniformly and uniformly deposited to form a deposited film composed of two or more materials in a ratio similar to the mixing ratio at the source. Under high vacuum, if the fluid is in free molecular flow mode, that is, the mean free path of molecules is greater than the size of the instrument. The rate of deposition is no longer dependent on pressure. That is, mass transfer is governed by molecular dynamics rather than fluid dynamics, since the continuum assumption of fluid dynamics no longer applies. For materials that do not melt during deposition, a direct transition from the solid phase to the gas phase occurs. When two materials are mixed and deposited from the same source under high vacuum, many factors can affect the deposition, such as the deposition temperature of the individual materials, the miscibility of the different materials, and the different phase transitions. Without wishing to be bound by theory, it is believed that similar deposition temperatures of the first and second materials contribute to deposition uniformity.

For purposes herein, deposition temperature is defined as the temperature at which a material can be deposited on a substrate under high vacuum at a specified rate. For example, as used herein, deposition temperature is the temperature of the organic material source as measured during thermal deposition at a rate suitable for device fabrication (in this case, ˜2-3 A/s at a pressure of ˜10″-10″ torr). am. Since the deposition temperature depends on the molecular weight intermolecular interactions of the material, identical molecularly modified derivatives may have the same molecular weight difference and similar intermolecular interactions. For example, in the case where the first compound and the second compound can be premixed and deposited with good uniformity, in the situation where the first compound is substituted with a phenyl group and the second compound is also substituted with a phenyl group, the first compound and The molecular weight added to the second compound is 77 atomic mass units (amu). Also, if the phenyl group induces similar molecular interactions for the first compound and the second compound, the deposition temperatures of the first compound having a phenyl substitution and the second compound having a phenyl substitution may be similar, and the mixture thereof is It may also be suitable for premix-deposition. Additionally, the first compound and the second compound may behave similarly even though the conditions in the deposition chamber are different. It may also be desirable for premix-deposition to result in similar device performance and lifetime compared to co-deposition. Thus, premixing the dopant and host compound in one deposition source provides uniform and consistent deposition of the two or more materials to form a deposited layer composed of the two or more materials in a ratio similar to the premix ratio.

Provided herein are novel combinations of materials in which an organic host compound is physically mixed with an organometallic phosphorescent dopant compound, which may be suitable for pre-mixture deposition or co-deposition. With respect to the pre-mixture deposition embodiments of the present invention, the organic host compound is physically mixed with an organometallic phosphorescent dopant. Certain combinations of materials disclosed herein show unexpected results by providing very constant ratios of the host compound and organometallic phosphorescent dopant in the film deposited from the pre-mix. Without wishing to be bound by theory, it is believed that the organometallic phosphorescent dopant and the heteroaromatic host compound have strong intermolecular interactions. Thus, by adjusting the deposition temperature of each compound, a constant deposition behavior is obtained. Accordingly, it is contemplated that the combination of a first compound selected from the organometallic phosphorescent dopant compounds disclosed herein and a second compound selected from the organic host compounds disclosed herein synergistically improves the properties of the resulting combination.

The organometallic phosphorescent dopant component of the material combination may act as an emissive dopant or it may act as an auxiliary dopant. When the organometallic phosphorescent dopant component of the pre-mixture serves as the auxiliary dopant, another organometallic phosphorescent compound present in the light emitting layer may serve as the light emitting dopant. Consequently, when the organometallic phosphorescent dopant component of the pre-mixture serves as the emissive dopant, the emissive layer may optionally contain other organometallic phosphorescent compounds which serve as the auxiliary dopant. In any case where the organometallic phosphorescent dopant component in the mixed material functions as an emissive dopant or auxiliary dopant, the relative triplet energy of the material in the emissive layer can be expressed as:

Emissive dopant < auxiliary dopant < host material

A material for use in an organic light emitting device and a light emitting layer thereof is provided. The organic light emitting device includes a first electrode, a second electrode, and a first organic layer deposited between the first and second electrodes, wherein the first organic layer comprises an organic composition. The organic composition includes a first compound and a second compound, wherein the first compound is _{an organometallic compound represented by the formula L 2} MX, LL'MX, LL'L"M, or LMXX', wherein L, L ', L", X, and X' are non-equivalent bidentate ligands, and M is a metal that forms an octahedral complex, wherein L, L', and L" are sp ² hybridized carbon and to M through a heteroatom. It is a coordinating monoanionic non-equivalent bidentate ligand, and the second compound has a heteroaromatic structure.

In one embodiment, the first compound may be a compound selected from the group consisting of a phosphorescent organometallic platinum compound, an organometallic iridium compound, and an organometallic osmium compound. The organometallic platinum compound, the iridium compound, and the osmium compound may each include an aromatic ligand.

In another embodiment, the first compound comprises a phosphorescent organometallic compound having a substituted chemical structure represented by the following chemical structure:

In the above formula,

M is Ir, Pt or Os;

each R′ is independently H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF ₃ , C _n F _2n+1 , trifluorovinyl, C0 ₂ R″, C(0)R″, NR " ₂ , N0 ₂ , OR", halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or heterocyclic group, wherein each R" is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;

Ar', Ar", Ar'" and Ar"" each independently represent a substituted or unsubstituted aryl or heteroaryl unfused substituent on a phenylpyridine ligand;

a is 0 or 1;

b is 0 or 1;

c is 0 or 1;

d is 0 or 1;

m is 1 or 2;

n is 1 or 2;

m+n is the maximum number of ligands that can be coordinated to M; wherein at least one of a, b, c, and d is 1, at least one of a and b is 1 and at least one of b and c is 1, then at least one of Ar′ and Ar″ is Ar′″ and Ar different from one or more of "".

The second compound comprises an organic heteroaromatic host compound having the formula (1):

<Formula 1>

In the above formula,

Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings.

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (1a):

<Formula 1a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (1b),

<Formula 1b>

Ring B is a heterocyclic ring represented by the following formula (1c),

<Formula 1c>

Rings A and B are each fused with an adjacent ring;

In formulas (1a) and (1b), X ¹ is O or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic hetero of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings. a cyclic group or an aromatic hydrocarbon group of 6 to 50 carbon atoms.

R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

When R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring.

X ¹ is O or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic heterocyclic group of 3 to 50 carbon atoms or 6 to 50 carbon atoms excluding groups having more than 5 condensed rings of an aromatic hydrocarbon group.

m means 0 or an integer of 1 to 2,

n means an integer of 0 or 1.

In formula (1c), X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms, excluding groups having more than 5 condensed rings, or 6 to It is an aromatic hydrocarbon group of 50 carbon atoms. X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group. X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group.

In the above-mentioned parts, ^{examples of Y or Ar 1} or Ar ² are benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally link two or more of these groups. Additionally, Y is a t-valent group and Ar ¹ and Ar ² are monovalent groups.

The second compound preferably comprises a heteroaromatic host compound represented by the following formula (2):

<Formula 2>

wherein Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms.

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (2a):

<Formula 2a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (2b),

<Formula 2b>

Ring B is a heterocyclic ring represented by the formula (2c),

<Formula 2c>

Rings A and B are each fused with an adjacent ring;

In formulas (2a) and (2b), R is independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms selected from the group.

when R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring;

m means 0 or an integer of 1 to 2,

n means an integer of 0 or 1.

In formula (2c), X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms, excluding groups having more than 5 condensed rings, or 6 to It is an aromatic hydrocarbon group of 50 carbon atoms.

In the above-mentioned examples of formula (2), Y or Ar ² is benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally link two or more of these groups. Additionally, Y is a t-valent group and Ar ² is a monovalent group.

The second compound preferably includes a heteroaromatic host compound represented by the following formula (3):

<Formula 3>

In formula (3), Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings .

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (3a):

<Formula 3a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (3b),

<Formula 3b>

Ring B is a heterocyclic ring represented by the formula (3c),

<Formula 3c>

rings A and B are each fused with an adjacent ring at any position;

In formulas (3a) and (3b), R is independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms selected from the group. Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

When R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring.

In formula (3c), Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms or an aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups condensed with more than 5 rings.

In the above-mentioned examples of formula (3), Y or Ar ² is benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally be linked to two or more of these groups. Additionally, Y is a t-valent group and Ar ² is a monovalent group.

In certain embodiments, the set of selected non-hydrogen substituents for each independent R′ and the set of selected non-hydrogen substituents for R are the same. As discussed above, identically molecularly modified derivatives of the first compound and the second compound will have the same molecular weight difference, which may have similar intermolecular interactions. Accordingly, the first compound and the second compound having the same substituent may be suitable for premixing.

In one embodiment, the first compound may be selected from, but not limited to, the group consisting of:

Methods for preparing such compounds are disclosed in US Patent Application Publication No. 2011/227049, which is incorporated herein by reference in its entirety.

The second compound represented by Formulas (1) and (2) and (3) may be selected from the group consisting of, but is not limited thereto:

Some examples of methods for the preparation of such compounds are disclosed in US Patent Application Publication Nos. 2009/0302742, 2010/0187977, 2012/0001165, which are incorporated herein by reference in their entirety.

As discussed above, identically molecularly modified derivatives of the first compound and the second compound will have the same molecular weight difference, which may have similar intermolecular interactions. Accordingly, the first compound and the second compound having the same substituent may be suitable for premixing.

In another embodiment, the device further comprises a second organic layer different from the first organic layer, wherein the second organic layer is a non-emissive layer. Preferably, the second organic layer is a blocking layer.

In one embodiment, the first electrode is an anode and the second organic layer is deposited on the anode.

In one embodiment, the first compound has a deposition temperature within 30° C. of the deposition temperature of the second compound.

In one embodiment, the organic composition comprises from about 5% to about 95% of the first compound and from about 5% to about 95% of the second compound.

In one embodiment, the device is an organic light emitting device. In other embodiments, the device is a consumer product.

Additionally, a method for manufacturing an organic light emitting device is provided. The device includes a first electrode, a second electrode, and a first organic layer deposited between the first electrode and the second electrode. The first organic layer includes an organic composition comprising a first compound and a second compound. In one embodiment, the first compound and the second compound are physically mixed prior to device fabrication and deposited from a single source. The method includes providing a substrate having a first electrode deposited thereon, depositing an organic composition on the first electrode; and depositing a second electrode on the first organic layer.

The organic composition comprises a first compound and a second compound, wherein the first compound is _{an organometallic compound represented by the formula L 2} MX, LL'MX, LL'L"M, or LMXX', wherein L, L', L″, X, and X′ are non-equivalent bidentate ligands, and M is a metal that forms an octahedral complex, wherein L, L′, and L″ ^{coordinate to M through an sp 2} hybridized carbon and a heteroatom. It is a monoanionic non-equivalent bidentate ligand, and the second compound is a compound having a heteroaromatic structure.

In one embodiment, the first compound may be a compound selected from the group consisting of a phosphorescent organometallic platinum compound, an organometallic iridium compound, and an organometallic osmium compound. The organometallic platinum compound, the iridium compound, and the osmium compound may each include an aromatic ligand.

In another embodiment, the first compound comprises a phosphorescent organometallic compound having a substituted chemical structure represented by the following chemical structure:

In the above formula,

M is Ir, Pt or Os;

each R′ is independently H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF ₃ , C _n F _2n+1 , trifluorovinyl, C0 ₂ R″, C(0)R″, NR " ₂ , N0 ₂ , OR", halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or heterocyclic group, wherein each R" is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;

Ar', Ar", Ar'" and Ar"" each independently represent a substituted or unsubstituted aryl or heteroaryl unfused substituent on a phenylpyridine ligand;

a is 0 or 1;

b is 0 or 1;

c is 0 or 1;

d is 0 or 1;

m is 1 or 2;

n is 1 or 2;

m+n is the maximum number of ligands that can be coordinated to M; wherein at least one of a, b, c, and d is 1, at least one of a and b is 1 and at least one of b and c is 1, then at least one of Ar′ and Ar″ is Ar′″ and Ar different from one or more of "".

The second compound comprises an organic heteroaromatic host compound having the formula (1):

<Formula 1>

In the above formula,

Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings.

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (1a):

<Formula 1a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (1b),

<Formula 1b>

Ring B is a heterocyclic ring represented by the following formula (1c),

<Formula 1c>

Rings A and B are each fused with an adjacent ring;

In formulas (1a) and (1b), X ¹ is O or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic hetero of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings. a cyclic group or an aromatic hydrocarbon group of 6 to 50 carbon atoms.

R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

When R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring.

X ¹ is O or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic heterocyclic group of 3 to 50 carbon atoms or 6 to 50 carbon atoms excluding groups having more than 5 condensed rings of an aromatic hydrocarbon group.

m is 0 or an integer of 1 to 2,

n is an integer of 0 or 1.

In formula (1c), X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms, excluding groups having more than 5 condensed rings, or 6 to It is an aromatic hydrocarbon group of 50 carbon atoms. X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group. X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group.

In the above-mentioned parts, ^{examples of Y or Ar 1} or Ar ² are benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally link two or more of these groups. Additionally, Y is a t-valent group and Ar ¹ and Ar ² are monovalent groups.

The second compound preferably comprises a heteroaromatic host compound represented by the following formula (2):

<Formula 2>

wherein Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms.

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (2a):

<Formula 2a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (2b),

<Formula 2b>

Ring B is a heterocyclic ring represented by the following formula (2c),

<Formula 2c>

Rings A and B are each fused with an adjacent ring;

Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

In formulas (2a) and (2b), R is independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms selected from the group.

when R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring;

m means 0 or an integer of 1 to 2,

n means an integer of 0 or 1.

In formula (2c), X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms, excluding groups having more than 5 condensed rings, or 6 to It is an aromatic hydrocarbon group of 50 carbon atoms.

In the above-mentioned examples of formula (2), Y or Ar ² is benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally link two or more of these groups. Additionally, Y is a t-valent group and Ar ² is a monovalent group.

The second compound preferably includes a heteroaromatic host compound represented by the following formula (3):

<Formula 3>

In formula (3), Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings .

t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.

Z is represented by the following formula (3a):

<Formula 3a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (3b),

<Formula 3b>

Ring B is a heterocyclic ring represented by the following formula (3c),

<Formula 3c>

rings A and B are each fused with an adjacent ring at any position;

In formulas (3a) and (3b), R is independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms selected from the group. Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.

When R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring.

In formula (3c), Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms or an aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings.

In the above-mentioned examples of formula (3), Y or Ar ² is benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthi Ridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole, benzothiazole , carbazole, dibenzofuran, dibenzothiophene, t-valent or monovalent groups derived from, or may optionally be linked to two or more of these groups. Additionally, Y is a t-valent group and Ar ² is a monovalent group.

In certain embodiments, the set of non-hydrogen substituents selected for each independent R′ and the set of non-hydrogen substituents selected for R are the same, and the method further deposits an organic composition on the first electrode. The method further comprises mixing the first compound and the second compound prior to the preparation.

In one embodiment, the first compound may be selected from, but not limited to, the group consisting of:

And the second compound represented by Formulas (1) and (2) and (3) may be selected from the group consisting of, but is not limited thereto:

In one embodiment, the first compound and the second compound are pre-mixed with each other and deposited from a single source.

In one embodiment, the organic composition comprises from about 5% to about 95% of the first compound and from about 5% to about 95% of the second compound.

In one embodiment, the first compound has a deposition temperature within 30° C. of the deposition temperature of the second compound. In other embodiments, the first compound has a deposition temperature within 10° C. of the deposition temperature of the second compound.

In one embodiment, the first electrode is an anode and the first organic layer is deposited on the anode.

In one embodiment, the method further comprises depositing a second organic layer different from the first organic layer, wherein the second organic layer is a non-emissive layer. In another embodiment, the second organic layer is a blocking layer.

The materials described herein useful for certain layers in organic light emitting devices can be used in combination with a wide variety of other materials present in the device. For example, the emissive dopants disclosed herein can be used in combination with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes, and other layers that may be present. The materials described or referenced below are non-limiting examples of materials that may be used in combination with the compounds disclosed herein, and those skilled in the art can readily refer to the literature to identify other materials that may be useful in combination.

A number of hole injection materials, hole transport materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transport and electron injection materials may be used in OLEDs other than and/or in combination with the materials disclosed herein.

Hole injecting material/hole transporting material:

The hole injection/transport material to be used in the present invention is not particularly limited, and any compound may be used as long as the compound is used as the hole injection/transport material. Non-limiting examples of substances include phthalocyanine or porphyrin derivatives; aromatic amine derivatives; indolocarbazole derivatives; polymers comprising fluorohydrocarbons; polymers with conductive dopants; conductive polymers such as PEDOT/PSS; self-assembling monomers derived from compounds such as phosphonic acids and silane derivatives; metal oxide derivatives such as MoO _x ; p-type semiconductor organic compounds such as 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile; metal complexes and crosslinkable compounds.

Non-limiting examples of aromatic amine derivatives used in HIL or HTL include the formula:

each Ar ¹ to Ar ⁹ is an aromatic hydrocarbon cyclic compound such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene the group consisting of; 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, oxadia gin, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, Aromatic heterocyclic compounds such as xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine the group consisting of; and an aromatic hydrocarbon cyclic group and an aromatic heterocyclic group, which are the same type or different types selected from an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, a chain structural unit and an aliphatic cyclic group directly or It is selected from the group consisting of 2 to 10 cyclic structural units bonded through at least one of them. Each Ar is further substituted with a substituent selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl and heteroaryl.

In one embodiment, Ar ¹ to Ar ⁹ are independently selected from the group consisting of:

In the above compounds, k is an integer from 1 to 20; X ¹ to X ⁸ are CH or N; Ar ¹ has the same group as defined above.

Examples of metal complexes used in HIL or HTL include, but are not limited to:

wherein M' is a metal having an atomic weight greater than 40; (Y ¹ -Y ² ) is a bidentate ligand, and Y ¹ and Y ² are independently selected from C, N, O, P and S; L is an auxiliary ligand; m is an integer from 1 to the maximum number of ligands that can be attached to the metal; and m+n is the maximum number of ligands that can be attached to the metal.

In one embodiment, (Y ¹ -Y ² ) is a 2-phenylpyridine derivative.

In other embodiments, (Y ¹ -Y ² ) is a carbene ligand.

In other embodiments, M is selected from Ir, Pt, Os and Zn.

In a further embodiment, the metal complex has a minimum oxidation potential in solution of less than about 0.6 V versus Fc ⁺ /Fc couple.

Host material:

The light emitting layer of the organic EL device of the present invention preferably comprises at least a metal complex as a light emitting material, and a host material disclosed herein. Additional host materials are possible, examples of which are not particularly limited. Any metal complex or organic compound may be used as long as the triplet energy of the host is greater than that of the dopant.

Examples of metal complexes used as hosts preferably have the following formula:

where M' is a metal; (Y ³ -Y ⁴ ) is a bidentate ligand, and Y ³ and Y ⁴ are independently selected from C, N, O, P and S; L is an auxiliary ligand; m is an integer value from 1 to the maximum number of ligands that can be bound to a metal; and m+n is the maximum number of ligands that can be attached to the metal.

In one embodiment, the metal complex is:

where (O-N) is a bidentate ligand having a metal coordinated to the atoms O and N.

In other embodiments, M is selected from Ir and Pt.

In a further embodiment, (Y ³ -Y ⁴ ) is a carbene ligand.

Examples of the organic compound used as the host include aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, ar the group consisting of julene; Aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolo Dipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, Oxatiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthala Gin, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine and selenophenodipyridine the group consisting of; and groups of the same type or different types selected from an aromatic hydrocarbon cyclic group and an aromatic heterocyclic group and are directly bonded to each other or are an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, a chain structural unit and an aliphatic group. It is selected from the group consisting of 2 to 10 cyclic structural units joined by one or more of the cyclic groups. wherein each group is further substituted with a substituent selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl and heteroaryl.

In one embodiment, the host compound comprises one or more of the following groups in the molecule:

wherein R ¹ to R ⁷ are independently selected from hydrogen, alkyl, amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl and heteroaryl, and when it is aryl or heteroaryl, it is have a similar definition.

k is an integer from 0 to 20;

X ¹ to X ⁸ are selected from CH or N.

Hole blocking materials:

The hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons emitted from the emission layer. The presence of such a blocking layer in a device can result in substantially higher efficiencies compared to similar devices lacking the blocking layer. A blocking layer can also be used to confine emission to a desired area of the OLED.

In one embodiment, the compound used in HBL comprises the same functional group or the same molecule used as the host described above.

In another embodiment, the compound used in HBL comprises one or more of the following groups in the molecule:

k is an integer from 1 to 20; L is an auxiliary ligand, and m is an integer from 1 to 3.

Electron transport materials:

The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be native (undoped) or doped. Doping can be used to improve conductivity. Examples of the ETL material are not particularly limited, and any metal complex or organic compound may be used as long as it is conventionally used to transport electrons.

In one embodiment, the compound used in ETL comprises one or more of the following groups in the molecule:

wherein R ¹ is selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl and heteroaryl, and when it is aryl or heteroaryl, it is have a similar definition.

Ar ¹ to Ar ³ have similar definitions to Ar described above.

k is an integer from 1 to 20;

X ¹ to X ⁸ are selected from CH or N.

In another embodiment, metal complexes used in ETL include, but are not limited to:

wherein (O-N) or (N-N) is a bidentate ligand having a metal coordinated to the atom O, N or N,N; L is an auxiliary ligand; m is an integer value from 1 to the maximum number of ligands that can be bound to a metal.

In addition to and/or in combination with the materials disclosed herein, a number of hole injection materials, hole transport materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transport and electron injection materials may be used in OLEDs. Non-limiting examples of materials that can be used in OLEDs in combination with the materials disclosed herein are set forth in Table 1 below. Table 1 below presents non-limiting types of substances, non-limiting examples of compounds for each type, and references disclosing substances.

[Table 1]

Experiment

Deposition Examples

Herein, a premix deposition in which a heteroleptic organometallic phosphor, ie, a first compound, and H1 or H2, ie, a second compound, has a high degree of uniformity is referred to. Deposition results are analyzed by high performance liquid chromatography (HPLC) of premix-deposited films and OLED performance and lifetime of devices with premix-deposited materials as hosts in EML.

Example 1.

H1 and D1 having the chemical structures shown above show stable premixability, meaning that they can be premixed and co-deposited from one source without changing the composition. Uniform co-deposition of the two materials is important for uniformity of performance in devices fabricated from these mixtures.

The premixability of these two compounds was tested by HPLC analysis of the deposited films. For this purpose, 0.39 g of H1 and 0.11 g of D1 were mixed and ground. 0.5 g of the mixture was charged to the deposition source of the vacuum VTE chamber. The chamber was pumped down to a pressure ^{of 10 -7 torr or less.} The premixed components were deposited on the organic substrate at a rate of 2 Å/s. The substrate was replaced continuously after deposition of 400 Angstroms of film without stopping the deposition and cooling the source.

The film was analyzed by HPLC, and the results are shown in Table 2. The composition of components H1 and D1 did not change significantly from plate 1 to plate 10. Some variations in concentration do not show any trends and can be explained by the accuracy of the HPLC analysis. In general, a change in concentration before and after deposition within 5% throughout the process is good and is considered useful for commercial OLED applications.

This is evidence that H1 and D1 form a stable co-deposition mixture.

Table 2 HPLC composition (%) of films continuously deposited from premixed dopant/host material combinations H1:D1

HPLC conditions C18, 80-100 40 min, detected wavelength 254 nm

Example 2

H2 and D1 (chemical structures shown above) represent other examples of stable premixing between these two classes of materials, meaning that they can be premixed and co-deposited from one source without changing the composition.

The premixability of these two compounds was tested by HPLC analysis of the deposited films. For this purpose, 0.84 g of H2 and 0.16 g of D1 were mixed and ground. 1 g of the mixture was charged to the deposition source of the vacuum VTE chamber. The chamber was pumped down to a pressure ^{of 10 -7 torr or less.} The premixed components were deposited on the organic substrate at a rate of 2 Å/s. The substrate was replaced continuously after deposition of 400 Angstroms of film without stopping the deposition and cooling the source.

The film was analyzed by HPLC, and the results are shown in Table 3. The composition of components H2 and D1 did not change significantly from plate 1 to plate 4. Some variations in concentration do not show any trends and can be explained by the accuracy of the HPLC analysis. In general, a change in concentration before and after deposition within 5% throughout the process is good and is considered useful for commercial OLED applications.

Table 3 HPLC composition (%) of films deposited continuously from premixed dopant/host material combination H2:D1

HPLC conditions C18, 80-100 40 min, detected wavelength 254 nm

It is to be understood that the various embodiments described herein are by way of illustration only and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein may be substituted for other materials and structures without departing from the spirit of the invention. The invention as claimed may thus include variations from the specific examples and preferred embodiments described herein as will be apparent to those skilled in the art. It will be understood that the various theories as to why the present invention works are not intended to be limiting.

Claims (16)

A method of manufacturing an organic light emitting device, the method comprising:
disposing the anode layer;
disposing a cathode layer, and
disposing a light emitting layer between the anode layer and the cathode layer
includes,
The step of disposing the light emitting layer here is,
forming a pre-mix material comprising a physical mixture of the first compound and the second compound; and
depositing the pre-mix material as a single source of deposition;
including,
wherein the first compound is _{an organometallic phosphorescent dopant compound having the formula L 2} MX, LL'MX, LL'L"M, or LMXX', wherein L, L', L", X, and X' are non-equivalent is an equivalent bidentate ligand, and M is a metal having an atomic weight greater than 40, wherein L, L', and L" are monoanionic nonequivalent ² coordinated to M via an sp 2 hybridized carbon a left ligand, and the organometallic phosphorescent dopant compound is selected from an organometallic platinum compound, an organometallic iridium compound and an organometallic osmium compound, wherein the organometallic platinum compound, the iridium compound and the osmium compound optionally include an aromatic ligand,
wherein the second compound is an organic heteroaromatic host compound having the formula (1):
<Formula 1>

In the above formula,
Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings.
t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.
Z is represented by the following formula (1a):
<Formula 1a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (1b),
<Formula 1b>

Ring B is a heterocyclic ring represented by the following formula (1c),
<Formula 1c>

Rings A and B are each fused with an adjacent ring;
Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.
when R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring;
m means 0 or an integer of 1 to 2,
n means an integer of 0 or 1.
X ¹ is 0 or S or N-Ar ¹ or N, wherein Ar ¹ is an aromatic heterocyclic group of 3 to 50 carbon atoms or 6 to 50 carbon atoms excluding groups having more than 5 condensed rings. of an aromatic hydrocarbon group.
X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group. The organic light emitting device of claim 1 , further comprising a third compound, wherein the third compound is an organometallic phosphorescent dopant different from the first compound, and triplet energy levels of the first compound, the second compound, and the third compound. How is the relationship of
third compound < first compound < second compound. The organic light emitting device of claim 1 , further comprising a third compound, wherein the third compound is an organometallic phosphorescent dopant different from the first compound, and triplet energy levels of the first compound, the second compound, and the third compound. How is the relationship of
first compound < third compound < second compound. According to any one of claims 1 to 3, wherein the first compound is represented by the following formula,

In the above formula,
M is Ir, Pt or Os,
each R′ is independently H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF ₃ , C _n F _2n+1 , trifluorovinyl, C0 ₂ R″, C(0)R″, NR " ₂ , N0 ₂ , OR", halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or heterocyclic group, wherein each R" is independently H, alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, or aralkyl;
Ar', Ar", Ar'" and Ar"" each independently represent a substituted or unsubstituted aryl or heteroaryl unfused substituent on a phenylpyridine ligand;
a is 0 or 1;
b is 0 or 1;
c is 0 or 1;
d is 0 or 1;
m' is 1 or 2;
n' is 1 or 2;
m'+n' is the maximum number of ligands that can be coordinated to M; wherein at least one of a, b, c, and d is 1, at least one of a and b is 1 and at least one of b and c is 1, then at least one of Ar′ and Ar″ is Ar′″ and Ar different from one or more of "";
wherein the second compound is an organic heteroaromatic host compound having the formula (2):
<Formula 2>

wherein Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms.
t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.
Z is represented by the following formula (2a):
<Formula 2a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (2b),
<Formula 2b>

Ring B is a heterocyclic ring represented by the following formula (2c),
<Formula 2c>

Rings A and B are each fused with an adjacent ring;
Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.
when R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring;
m means 0 or an integer of 1 to 2,
n means an integer of 0 or 1.
X ² is O or S or N-Ar ² , wherein Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or an aromatic group of 6 to 50 carbon atoms is a hydrocarbon group. 4. The method according to any one of claims 1 to 3, wherein the second compound is an organic heteroaromatic host compound having the formula (3):
<Formula 3>

wherein Y is a t-valent aromatic heterocyclic group of 3 to 50 carbon atoms excluding groups having more than 5 condensed rings or a t-valent aromatic hydrocarbon group of 6 to 50 carbon atoms.
t means an integer from 1 to 3, provided that when t is greater than 2, each Z may be the same or different.
Z is represented by the following formula (3a):
<Formula 3a>

In the above formula, ring A is an aromatic hydrocarbon ring represented by the following formula (3b),
<Formula 3b>

Ring B is a heterocyclic ring represented by the following formula (3c),
<Formula 3c>

Rings A and B are each fused with an adjacent ring;
Each R is independently selected from hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, or an aromatic heterocyclic group of 3 to 17 carbon atoms.
When R is an aromatic hydrocarbon group or an aromatic heterocyclic group, R may be condensed with a benzene ring.
Ar ² is an aromatic heterocyclic group of 3 to 50 carbon atoms or an aromatic hydrocarbon group of 6 to 50 carbon atoms excluding groups having more than 5 condensed rings. 4. The method of any one of claims 1 to 3, wherein each of Ar and Y is benzene, naphthalene, anthracene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, isoindole, indazole, purine, isoquinoline, imidazole, naphthyridine, phthalazine, quinazoline, quinoxaline, cinnoline, quinoline, pteridine, phenanthridine, acridine, perimidine, phenanthroline, phenazine, carboline, indole, benzoxazole , benzothiazole, carbazole, dibenzofuran, dibenzothiophene, and a group derived from an aromatic compound, wherein a plurality of said groups are linked to each other. The method of claim 1 , wherein the first compound has a deposition temperature within 30° C. of the deposition temperature of the second compound. 4. The deposition of claim 2 or 3, wherein at least one of the first compound, the second compound and the third compound is within 30°C of the deposition temperature of at least one of the remaining ones of the first compound, the second compound and the third compound. How to have a temperature. 4. The deposition of claim 2 or 3, wherein at least one of the first compound, the second compound and the third compound is deposited within 10° C. of the deposition temperature of at least one of the remaining ones of the first compound, the second compound and the third compound. How to have a temperature. 4. The method of claim 2 or 3, wherein each of the first compound, the second compound and the third compound each has a deposition temperature within 30° C. of the other. 4. The method of claim 2 or 3, wherein the first compound has a deposition temperature within 30° C. of the deposition temperature of the third compound. 4. The method of claim 2 or 3, wherein the second compound has a deposition temperature within 30°C of the deposition temperature of the third compound. 4. The method of claim 2 or 3, wherein the first compound has a deposition temperature within 30°C of the deposition temperature of the second compound. 4. The method of claim 2 or 3, wherein the pre-mixed material further comprises a third compound. A method of forming a light emitting layer for an OLED using a composition comprising a deposited pre-mix material, the deposited pre-mix material comprising a physical mixture of a first compound and a second compound, the first compound comprising a first compound A method comprising the first compound of claim 1 , wherein the second compound comprises the second compound of claim 1 . A method of forming a light emitting layer for an OLED using a composition comprising a pre-mix material, wherein the pre-mix material comprises a physical mixture of a first compound and a second compound, wherein the first compound is the first compound of claim 1 . wherein the second compound comprises the second compound of claim 1.

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