Organic electroluminescent device and display device

Abstract

Disclosed are an organic electroluminescent device and a display device. The organic electroluminescent device includes an anode, a cathode, and a first light-emitting layer, a second light-emitting layer, and an electron transport region disposed between the anode and the cathode, the first light-emitting layer and the second light-emitting layer emitting light of different peak wavelengths having a difference of 50 nm, the electron transport region including a first organic layer, the first organic layer includes a first organic material represented by a structure of Formula 1. According to the organic light-emitting device, the first organic material represented by the structure shown in the formula 1 is introduced into the first organic layer, carrier transmission in the device can be balanced, and therefore more excellent comprehensive device performance can be obtained, for example, higher EQE and / or lower voltage are / is achieved. And the color temperature can be effectively regulated and controlled, so that an excellent cold white light standard is achieved. The invention further discloses a display device comprising the organic light-emitting device.

Description

Technical Field

[0001] The present invention relates to an organic electronic device, such as an organic electroluminescent device, and more particularly to an organic electroluminescent device comprising a first organic material in a first organic layer included in an electron transport region, and a display device comprising the organic electroluminescent device. Background Art

[0002] Organic electronic devices include, but are not limited to, the following categories: organic light-emitting diodes (OLEDs), organic field-effect transistors (O-FETs), organic light-emitting transistors (OLETs), organic photovoltaics (OPVs), dye-sensitized solar cells (DSSCs), organic photodetectors, organic photoreceptors, organic field-effect devices (OFQDs), light-emitting electrochemical cells (LECs), organic laser diodes, and organic electroluminescent devices.

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a double-layer organic electroluminescent device that included an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light-emitting layer (Applied Physics Letters, 1987, 51(12):913-915). Once a bias voltage was applied to the device, green light was emitted from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). The most advanced OLEDs can include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more light-emitting layers between the cathode and anode. Since OLEDs are self-luminous solid-state devices, they offer great potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, can make them very suitable for special applications, such as on flexible substrates.

[0004] With the rapid development of display technology, organic light-emitting diodes (OLEDs) have gained a significant position in the contemporary display market due to their superior display performance, including high contrast, wide color gamut, and flexible form factors. Their application is particularly widespread in the small and medium-sized display market. However, in large-screen applications such as televisions, OLED screens have been slow to develop. The traditional vapor deposition method for producing large-scale OLED displays is limited by the mask process, and currently, a white light OLED device plus a filter is generally used. Therefore, the production of higher-performance white light devices is of great significance for the breakthrough of OLED in the large-scale display market.

[0005] Carbazole compounds are generally used as the main material in monochrome devices or as hole transport materials, such as the prior art US2015380662A1 and US2022310936A1. In multicolor or white light OLED devices, there is no prior art disclosure that such compounds can be used in the electron transport region in such devices. White light OLED devices generally include multiple light-emitting layers (EML), such as a yellow light-emitting layer and a blue light-emitting layer. In order to obtain high-efficiency and long-life white light devices, the yellow light-emitting layer usually uses a phosphorescent light-emitting material, while the blue light-emitting layer uses a fluorescent light-emitting material. However, in such a device structure containing multiple light-emitting layers, there are usually problems such as carrier imbalance, insufficient device performance, and unsatisfactory color temperature. Therefore, in the research of white light OLED devices, how to better regulate the carrier balance in the device to improve device performance while also regulating the color temperature is a huge challenge. Summary of the Invention

[0006] The present invention aims to provide an organic electroluminescent device to solve at least some of the above problems. The organic electroluminescent device of the present invention comprises a first light-emitting layer, a second light-emitting layer and an electron transport region, wherein the first light-emitting layer and the second light-emitting layer emit light with different peak wavelengths having a difference of 50 nm, and the electron transport region comprises a first organic layer, and the first organic layer comprises a first organic material represented by the structure of Formula 1. The organic electroluminescent device of the present invention helps to balance the carrier transport in the device by introducing the first organic material represented by the structure of Formula 1 into the first organic layer, thereby obtaining better overall device performance, for example, compared to devices using commercial materials in the first organic layer, having higher EQE and / or lower voltage. In addition, the organic electroluminescent device of the present invention can also effectively regulate the color temperature, thereby achieving an excellent cool white light standard.

[0007] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0008] anode;

[0009] cathode;

[0010] and a first light-emitting layer, a second light-emitting layer, and an electron transport region disposed between the anode and the cathode;

[0011] The first light-emitting layer emits light having a first peak wavelength, the second light-emitting layer emits light having a second peak wavelength, and an absolute value of a difference between the first peak wavelength and the second peak wavelength is greater than or equal to 50 nm;

[0012] The electron transport region includes a first organic layer, the first organic layer includes a first organic material, and the first organic material has a structure represented by Formula 1:

[0013]

[0014] in,

[0015] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof;

[0016] Each occurrence of X is selected from CR x or N;

[0017] Each occurrence of R is the same or different and represents mono-, poly-, or unsubstituted;

[0018] R and R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0019] Adjacent substituents R and R x Can optionally be linked to form a ring.

[0020] According to one embodiment of the present invention, a display device is disclosed, which includes the organic electroluminescent device described in the above embodiment.

[0021] The organic electroluminescent device of the present invention comprises a first light-emitting layer, a second light-emitting layer and an electron transport region, wherein the first light-emitting layer and the second light-emitting layer emit light with different peak wavelengths having a difference of 50 nm, and the electron transport region comprises a first organic layer, wherein the first organic layer comprises a first organic material represented by the structure of Formula 1. The organic electroluminescent device of the present invention helps to balance the carrier transport in the device by introducing the first organic material represented by the structure of Formula 1 into the first organic layer, thereby achieving better device performance, for example, a higher EQE and / or lower voltage compared to a device using commercial materials in the first organic layer. In addition, the organic electroluminescent device of the present invention can also effectively control the color temperature, thereby achieving an excellent cool white light standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 3 is a schematic structural diagram of a typical stacked OLED device 300 .

[0023] Figure 2 is a schematic diagram of an organic electroluminescent device of the present invention.

[0024] Figure 3 is a schematic diagram of another organic electroluminescent device of the present invention.

[0025] Figure 4 The device of Comparative Example 5 is 1000cd / m 2 The spectrum below.

[0026] Figure 5 The device embodiment 3 of the present invention is 1000cd / m 2 The spectrum below. DETAILED DESCRIPTION

[0027] As used herein, "top" means farthest from the substrate, while "bottom" means closest to the substrate. When a first layer is described as being "disposed on" 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, other layers may be present between the first and second layers. For example, the cathode may be described as being "disposed on" the anode even if various organic layers are present between the cathode and the anode.

[0028] As used herein, the term "organic electroluminescent device" (OLED device) includes an anode layer, a cathode layer, and one or more organic layers disposed between the anode layer and the cathode layer. An "OLED device" can be bottom-emitting, i.e., emitting light from the substrate side, top-emitting, i.e., emitting light from the encapsulation layer side, or a transparent device, i.e., emitting light from both the substrate and encapsulation sides.

[0029] As used herein, the term "module" refers to an electronic device that has only one set of external electrical drive devices.

[0030] As used herein, the term "encapsulation layer" may be a thin film encapsulation with a thickness of less than 100 microns, which includes one or more thin films directly disposed on the device, or may be a cover glass adhered to a substrate.

[0031] As used herein, "electron transport region" refers to a region that primarily transports electrons, and may be the region between the light-emitting layer closest to the cathode and the cathode, or the region between the light-emitting layer and the charge generation layer closest to the light-emitting layer and close to the cathode. For example, for a single-layer device, the "electron transport region" refers to the region between the light-emitting layer closest to the cathode and the cathode, which may include multiple organic layers, such as a hole blocking layer, an electron transport layer, and an electron injection layer. Those skilled in the art will appreciate that there may be multiple electron transport regions in the device of the present invention. For example, for a stacked device, it has multiple light-emitting units, a charge generation layer is provided between two adjacent light-emitting units, and each light-emitting unit has an electron transport region. In this case, the "electron transport region" includes the organic layers provided between the light-emitting layer and the charge generation layer closest to the light-emitting layer and close to the cathode; and the "electron transport region" includes the organic layers provided between the light-emitting layer closest to the cathode and the cathode. In addition, the positional relationship between the multiple light-emitting units in the stacked device between the anode and the cathode can be arbitrary and can be set according to actual needs. For example, a stacked white light device generally includes a yellow light emitting unit and a blue light emitting unit, and the blue light emitting unit can be arranged near the anode or near the cathode. When the blue light emitting unit is arranged near the anode and the yellow light emitting unit is arranged near the cathode, the "electron transport region" can be arranged between the light emitting layer and the charge generation layer of the blue light emitting unit; when the yellow light emitting unit is arranged near the anode and the blue light emitting unit is arranged near the cathode, the "electron transport region" can be arranged between the light emitting layer and the cathode of the blue light emitting unit. Those skilled in the art will understand that the electron transport region referred to herein does not include the light emitting layer.

[0032] As used herein, the terms "first light-emitting layer," "second light-emitting layer," and the like are used to describe, but should not be limited by, these terms, which are merely used to distinguish one light-emitting layer from another.

[0033] As used herein, a "charge generation layer" is a layer disposed between two light-emitting units that provides electrons and holes. Preferably, the "charge generation layer" comprises a metal layer and a buffer layer, wherein the metal layer is an n-type charge generation layer, comprising a metal material that acts as an n-type material to generate electrons, and the "buffer layer" is a layer that optimizes the interface, and optionally also generates holes. The "charge generation layer" may further comprise a p-type charge generation layer, wherein the p-type charge generation layer further comprises a p-type material to generate holes.

[0034] As used herein, a "single-layer device" refers to a device structure with one or more light-emitting layers between a pair of cathodes and anodes, but only one set of hole-transporting and electron-transporting regions. The hole-transporting region may include multiple organic layers, such as a hole-injection layer, a hole-transporting layer, and an electron-blocking layer; the electron-transporting region may include multiple organic layers, such as a hole-blocking layer, an electron-transporting layer, and an electron-injection layer.

[0035] A typical structure diagram of a stacked OLED device 300 is shown in FIG. Figure 1 As shown, it includes an anode layer 301, a first light-emitting unit 302, a charge generation layer (CGL) 303, a second light-emitting unit 304, and a cathode layer 305. The charge generation layer 303 is generally composed of an n-type material and a p-type material, and a buffer layer may also be added, as described in patent application CN112687811A. If the stacked device is a top-emitting device, a capping layer (not shown) may also be added above the cathode layer 305. Figure 3 The device shown is a 2-unit stacked device, and a third light-emitting unit and a second charge generation layer can be added to form a 3-unit stacked device. The preparation of stacked OLED devices is well known in the industry and will not be described in detail here.

[0036] In OLED (Organic Light Emitting Diode) technology, the color temperature of white light can range widely. Color temperature is measured in Kelvin (K) and represents the temperature of the color of the light source. In the industry, warm white generally refers to a color temperature between 2000K and 3500K, showing a warmer and more comfortable yellow or orange tone. Neutral white refers to 3500K to 5000K. Cool white refers to a color temperature above 5000K, up to 7000K or even higher, and the light has a cooler blue tone. Preferably, the color temperature of cool white light is between 6000K and 11000K; more preferably, the color temperature of cool white light is between 6000K and 8000K.

[0037] Devices manufactured according to embodiments of the present invention can be incorporated into various consumer products having one or more electronic component modules (or units) of the device. Some examples of these consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, smartphones, tablet computers, tablet phones, wearable devices, smart watches, laptop computers, digital cameras, camcorders, viewfinders, microdisplays, 3-D displays, vehicle displays, and taillights.

[0038] Definition of Substituent Terms

[0039] Halogen or halide - as used herein, includes fluorine, chlorine, bromine and iodine.

[0040] Alkyl - as used herein, includes straight chain and branched chain alkyl groups. The alkyl group may be an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, 3-methylpentyl. Among the above, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl and n-hexyl are preferred. In addition, the alkyl group may be optionally substituted.

[0041] Cycloalkyl - as used herein, includes cyclic alkyl groups. Cycloalkyl groups can be cycloalkyl groups having 3 to 20 ring carbon atoms, preferably cycloalkyl groups having 4 to 10 carbon atoms. Examples of cycloalkyl groups include cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl, and the like. Of the above, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, and 4,4-dimethylcyclohexyl are preferred. In addition, the cycloalkyl group may be optionally substituted.

[0042] Heteroalkyl - As used herein, a heteroalkyl group comprises one or more carbon atoms in the alkyl chain substituted with a heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, selenium, phosphorus, silicon, germanium, and boron atoms. The heteroalkyl group may be a heteroalkyl group having 1 to 20 carbon atoms, preferably a heteroalkyl group having 1 to 10 carbon atoms, and more preferably a heteroalkyl group having 1 to 6 carbon atoms. The example of heteroalkyl includes methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermanylmethyl, trimethylgermanylethyl, trimethylgermanylisopropyl, dimethylethylgermanylmethyl, dimethylisopropylgermanylmethyl, tert-butyldimethylgermanylmethyl, triethylgermanylmethyl, triethylgermanylethyl, triisopropylgermanylmethyl, triisopropylgermanylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl, triisopropylsilylethyl. In addition, heteroalkyl can be optionally substituted.

[0043] Alkenyl - as used herein, encompasses straight chain, branched chain, and cyclic olefin groups. Alkenyl groups can be alkenyl groups containing 2 to 20 carbon atoms, preferably alkenyl groups having 2 to 10 carbon atoms. Examples of alkenyl groups include ethenyl, propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, styryl, 2,2-diphenylvinyl, 1,2-diphenylvinyl, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1-phenylallyl, 2-phenylallyl, 3-phenylallyl, 3,3-diphenylallyl, 1,2-dimethylallyl, 1-phenyl-1-butenyl, 3-phenyl-1-butenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl, cycloheptatrienyl, cyclooctenyl, cyclooctatetraenyl, and norbornenyl. Additionally, alkenyl groups can be optionally substituted.

[0044] Alkynyl - as used herein, encompasses straight chain alkynyl groups. Alkynyl groups can be alkynyl groups comprising 2 to 20 carbon atoms, preferably alkynyl groups having 2 to 10 carbon atoms. Examples of alkynyl groups include ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3,3-dimethyl-1-butynyl, 3-ethyl-3-methyl-1-pentynyl, 3,3-diisopropyl-1-pentynyl, phenylethynyl, phenylpropynyl, etc. Among the above, ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, phenylethynyl, etc. are preferred. In addition, alkynyl groups can be optionally substituted.

[0045] Aryl or aromatic group - As used herein, both non-fused and fused systems are contemplated. The aryl group can be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthren, fluorene, pyrene, Perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. Examples of non-fused aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenyl, 4"-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl and m-quaterphenyl. In addition, the aryl group may be optionally substituted.

[0046] Heterocyclic group or heterocycle - as used herein, non-aromatic cyclic groups are contemplated. Non-aromatic heterocyclic groups include saturated heterocyclic groups having 3-20 ring atoms and unsaturated non-aromatic heterocyclic groups having 3-20 ring atoms, wherein at least one ring atom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium and boron atoms, and preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms, including at least one heteroatom such as nitrogen, oxygen, silicon or sulfur. Examples of non-aromatic heterocyclic groups include oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxopentanyl, dioxanyl, aziridinyl, dihydropyrrolyl, tetrahydropyrrolyl, piperidinyl, oxazolidinyl, morpholinyl, piperazinyl, oxepinyl, thiepinyl, azepine and tetrahydrothiol. Additionally, heterocyclyl groups may be optionally substituted.

[0047] Heteroaryl - As used herein, non-fused and fused heteroaromatic groups may contain from 1 to 5 heteroatoms, at least one of which is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium, and boron. Heteroaryl also refers to heteroaryl. The heteroaryl group may have from 3 to 30 carbon atoms, preferably from 3 to 20 carbon atoms, and more preferably from 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indole, carbazole, pyridine, indole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, In some embodiments, the heteroaryl group comprises an oxadiazole, an isocyanine ...

[0048] Alkoxy - as used herein, is represented by -O-alkyl, -O-cycloalkyl, -O-heteroalkyl, or -O-heterocyclyl. Examples and preferred examples of alkyl, cycloalkyl, heteroalkyl, and heterocyclyl are the same as those described above. The alkoxy group may be an alkoxy group having 1 to 20 carbon atoms, preferably an alkoxy group having 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy, and ethoxymethyloxy. In addition, the alkoxy group may be optionally substituted.

[0049] Aryloxy - As used herein, it is represented by -O-aryl or -O-heteroaryl. Examples and preferred examples of aryl and heteroaryl groups are the same as those described above. The aryloxy group may be an aryloxy group having 6 to 30 carbon atoms, preferably an aryloxy group having 6 to 20 carbon atoms. Examples of the aryloxy group include phenoxy and biphenyloxy. In addition, the aryloxy group may be optionally substituted.

[0050] Aralkyl - as used herein, encompasses aryl-substituted alkyl groups. The aralkyl group may be an aralkyl group having 7 to 30 carbon atoms, preferably an aralkyl group having 7 to 20 carbon atoms, and more preferably an aralkyl group having 7 to 13 carbon atoms. Examples of aralkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl tert-butyl, α-naphthylmethyl, 1-α-naphthyl-ethyl, 2-α-naphthylethyl, 1-α-naphthylisopropyl, 2-α-naphthylisopropyl, β-naphthylmethyl, 1-β-naphthyl-ethyl, 2-β-naphthyl-ethyl, 1-β-naphthylisopropyl, 2-β-naphthylisopropyl, p-methylbenzyl, m-methylbenzyl, substituted alkyl.Alkyl group can be substituted alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl, alkyl,

[0051] Alkylsilyl - As used herein, encompasses alkyl-substituted silicon groups. The alkylsilyl group may be an alkylsilyl group having 3 to 20 carbon atoms, preferably an alkylsilyl group having 3 to 10 carbon atoms. Examples of alkylsilyl groups include trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tri-tert-butylsilyl, triisobutylsilyl, dimethyl-tert-butylsilyl, and methyldi-tert-butylsilyl. Additionally, the alkylsilyl group may be optionally substituted.

[0052] Arylsilyl - As used herein, encompasses silicon groups substituted with at least one aryl group. The arylsilyl group may be one having 6 to 30 carbon atoms, preferably one having 8 to 20 carbon atoms. Examples of arylsilyl groups include triphenylsilyl, phenyldibiphenylsilyl, diphenylbiphenylsilyl, phenyldiethylsilyl, diphenylethylsilyl, phenyldimethylsilyl, diphenylmethylsilyl, phenyldiisopropylsilyl, diphenylisopropylsilyl, diphenylbutylsilyl, diphenylisobutylsilyl, and diphenyltert-butylsilyl. Additionally, the arylsilyl group may be optionally substituted.

[0053] Alkylgermanyl - As used herein, alkyl-substituted germanium groups are encompassed. The alkylgermanyl group can be an alkylgermanyl group having 3 to 20 carbon atoms, preferably an alkylgermanyl group having 3 to 10 carbon atoms. Examples of alkylgermanyl groups include trimethylgermanyl, triethylgermanyl, methyldiethylgermanyl, ethyldimethylgermanyl, tripropylgermanyl, tributylgermanyl, triisopropylgermanyl, methyldiisopropylgermanyl, dimethylisopropylgermanyl, tri-tert-butylgermanyl, triisobutylgermanyl, dimethyl-tert-butylgermanyl, and methyldi-tert-butylgermanyl. Additionally, the alkylgermanyl group can be optionally substituted.

[0054] Arylgermanyl - As used herein, encompasses germanium groups substituted with at least one aryl or heteroaryl group. The arylgermanyl group may be one having 6 to 30 carbon atoms, preferably one having 8 to 20 carbon atoms. Examples of arylgermanyl groups include triphenylgermanyl, phenyldibiphenylgermanyl, diphenylbiphenylgermanyl, phenyldiethylgermanyl, diphenylethylgermanyl, phenyldimethylgermanyl, diphenylmethylgermanyl, phenyldiisopropylgermanyl, diphenylisopropylgermanyl, diphenylbutylgermanyl, diphenylisobutylgermanyl, and diphenyltert-butylgermanyl. Additionally, the arylgermanyl group may be optionally substituted.

[0055] The term "aza" in azadibenzofuran, azadibenzothiophene, etc., means that one or more CH groups in the corresponding aromatic moiety are replaced by a nitrogen atom. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline, and other analogs having two or more nitrogen atoms in the ring system. Other nitrogen analogs of the above-mentioned aza derivatives will readily occur to one of ordinary skill in the art, and all such analogs are intended to be included within the terminology described herein.

[0056] In the present disclosure, unless otherwise defined, when any one of the terms in the group consisting of substituted alkyl, substituted cycloalkyl, substituted heteroalkyl, substituted heterocyclyl, substituted aralkyl, substituted alkoxy, substituted aryloxy, substituted alkenyl, substituted alkynyl, substituted aryl, substituted heteroaryl, substituted alkylsilyl, substituted arylsilyl, substituted alkylgermanyl, substituted arylgermanyl, substituted amino, substituted acyl, substituted carbonyl, substituted carboxylic acid , substituted ester group, substituted sulfinyl group, substituted sulfonyl group, substituted phosphino group, refers to alkyl, cycloalkyl, heteroalkyl, heterocyclic group, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, alkylgermanyl, arylgermanyl, amino, acyl, carbonyl, carboxylic acid group, ester group, sulfinyl, sulfonyl and phosphino group, any one of which may be selected from deuterium, halogen, unsubstituted alkyl group having 1 to 20 carbon atoms, unsubstituted cycloalkyl having 3-20 ring carbon atoms, unsubstituted heteroalkyl having 1-20 carbon atoms, unsubstituted heterocyclyl having 3-20 ring atoms, unsubstituted aralkyl having 7-30 carbon atoms, unsubstituted alkoxy having 1-20 carbon atoms, unsubstituted aryloxy having 6-30 carbon atoms, unsubstituted alkenyl having 2-20 carbon atoms, unsubstituted alkynyl having 2-20 carbon atoms, unsubstituted alkyl having 6-30 carbon atoms aryl, unsubstituted heteroaryl having 3 to 30 carbon atoms, unsubstituted alkylsilyl having 3 to 20 carbon atoms, unsubstituted arylsilyl having 6 to 20 carbon atoms, unsubstituted alkylgermanyl having 3 to 20 carbon atoms, unsubstituted arylgermanyl having 6 to 20 carbon atoms, unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphino and combinations thereof.

[0057] It should be understood that when describing a molecular fragment as a substituent or otherwise attached to another moiety, its name can be written according to whether it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is an entire molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attaching a fragment are considered equivalent.

[0058] In the compounds described herein, hydrogen atoms may be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen may also be replaced by their other stable isotopes. The replacement of other stable isotopes in compounds may be preferred because it enhances device efficiency and stability.

[0059] In the compounds described herein, polysubstitution refers to a range including disubstitution up to the maximum number of available substitutions. When a substituent in a compound described herein represents polysubstitution (including disubstitution, trisubstitution, tetrasubstitution, etc.), it means that the substituent can be present at multiple available substitution positions on its connected structure, and the substituents present at multiple available substitution positions can have the same structure or different structures.

[0060] In the compounds mentioned in the present disclosure, unless clearly defined, such as adjacent substituents can be optionally connected to form a ring, otherwise adjacent substituents in the compound cannot be connected to form a ring. In the compounds mentioned in the present disclosure, adjacent substituents can be optionally connected to form a ring, including the situation where adjacent substituents can be connected to form a ring, and also including the situation where adjacent substituents are not connected to form a ring. When adjacent substituents can be optionally connected to form a ring, the formed ring can be a monocyclic or polycyclic ring (including spirocyclic, bridged ring, condensed ring, etc.), as well as an alicyclic, heteroalicyclic, aromatic or heteroaromatic ring. In this statement, adjacent substituents can refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to carbon atoms further away. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0061] The statement that adjacent substituents can optionally be linked to form a ring is also intended to be taken to mean that two substituents bonded to the same carbon atom are linked to each other by a chemical bond to form a ring, as can be exemplified by the following formula:

[0062]

[0063] The statement that adjacent substituents can optionally be linked to form a ring is also intended to be taken to mean that two substituents bonded to carbon atoms directly bonded to each other are linked to each other via a chemical bond to form a ring, as can be exemplified by the following formula:

[0064]

[0065] The statement that adjacent substituents can optionally be linked to form a ring is also intended to be taken to mean that two substituents bonded to further distant carbon atoms are linked to each other by a chemical bond to form a ring, as can be exemplified by the following formula:

[0066]

[0067] Furthermore, the statement that adjacent substituents can optionally be linked to form a ring is also intended to mean that, in the case where one of the two adjacent substituents represents hydrogen, the second substituent is bonded to the position to which the hydrogen atom is bonded, thereby forming a ring. This is exemplified by the following formula:

[0068]

[0069] According to one embodiment of the present invention, an organic electroluminescent device is disclosed, comprising:

[0070] anode;

[0071] cathode;

[0072] and a first light-emitting layer, a second light-emitting layer, and an electron transport region disposed between the anode and the cathode;

[0073] The first light-emitting layer emits light having a first peak wavelength, the second light-emitting layer emits light having a second peak wavelength, and an absolute value of a difference between the first peak wavelength and the second peak wavelength is greater than or equal to 50 nm;

[0074] The electron transport region includes a first organic layer, the first organic layer includes a first organic material, and the first organic material has a structure represented by Formula 1:

[0075]

[0076] in,

[0077] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof;

[0078] Each occurrence of X is selected from CR x or N;

[0079] Each occurrence of R is the same or different and represents mono-, poly-, or unsubstituted;

[0080] R and R xEach occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0081] Adjacent substituents R and R x Can optionally be linked to form a ring.

[0082] In this context, “adjacent substituents R and R x "can optionally be linked to form a ring" is intended to mean that adjacent substituent groups, for example, between two substituents R, and between two substituents R x Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0083] According to an embodiment of the present invention, the first organic material is a p-type material.

[0084] According to one embodiment of the present invention, each occurrence of X is the same or different and is selected from CR x .

[0085] According to one embodiment of the present invention, wherein R and R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 20 carbon atoms, cyano, and combinations thereof.

[0086] According to one embodiment of the present invention, wherein R and R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, cyano, and combinations thereof.

[0087] According to one embodiment of the present invention, wherein R and R x Each occurrence is identically or differently selected from the group consisting of: hydrogen, deuterium, fluorine, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, cyano, and combinations thereof.

[0088] According to one embodiment of the present invention, wherein Ar is selected from a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms, or a combination thereof.

[0089] According to one embodiment of the present invention, Ar is selected from a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a combination thereof.

[0090] According to one embodiment of the present invention, wherein the Ar is selected from the group consisting of: substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, and combinations thereof.

[0091] According to one embodiment of the present invention, the first organic material is selected from the group consisting of Compound A-1 to Compound A-56, and the specific structures of Compound A-1 to Compound A-56 are shown in Claim 5.

[0092] According to one embodiment of the present invention, the hydrogen in Compound A-1 to Compound A-51, Compound A-53 to Compound A-56 can be partially or completely replaced by deuterium.

[0093] According to one embodiment of the present invention, the first organic layer is an electron transport layer.

[0094] According to one embodiment of the present invention, the first organic layer comprises at least one metal element or metal compound.

[0095] According to one embodiment of the present invention, the metal compound is selected from one or more of the following groups: 8-hydroxyquinoline-lithium, 8-hydroxyquinoline-sodium, 8-hydroxyquinoline-potassium, di(8-hydroxyquinoline)-beryllium, di(8-hydroxyquinoline)-magnesium, di(8-hydroxyquinoline)-calcium, tri(8-hydroxyquinoline)-aluminum, tri(8-hydroxyquinoline)-gallium, LiF; and the metal element is selected from Yb or Li.

[0096] According to one embodiment of the present invention, the first organic layer comprises 8-hydroxyquinoline-lithium (Liq).

[0097] According to one embodiment of the present invention, the first organic layer may further include a second organic material, and the second organic material is an electron transport compound.

[0098] According to one embodiment of the present invention, the second organic material has a structure represented by Formula 2:

[0099]

[0100] in,

[0101] Z is selected from O, S or Se;

[0102] Each occurrence of A1-A6 is selected from CR a or N;

[0103] R y , R z Each occurrence of the same or different means mono-, poly- or no-substitution;

[0104] R a , R y and R zEach occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0105] Ar1 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof.

[0106] According to one embodiment of the present invention, wherein the R y and R z At least one of them is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0107] According to one embodiment of the present invention, the Ar1 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0108] According to one embodiment of the present invention, wherein the Ar1 is selected from a substituted or unsubstituted aryl group having 10 to 30 carbon atoms.

[0109] According to one embodiment of the present invention, the Z is selected from O or S.

[0110] According to one embodiment of the present invention, Z is O.

[0111] According to one embodiment of the present invention, wherein said A1-A6 are selected from CR a .

[0112] According to one embodiment of the present invention, wherein the R aEach occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof.

[0113] According to one embodiment of the present invention, wherein the R a The group consisting of hydrogen, deuterium, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, and combinations thereof is selected at each occurrence, either identically or differently.

[0114] According to one embodiment of the present invention, wherein the R y and R z At least one of them is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; the rest of R y and R z Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, and combinations thereof.

[0115] According to one embodiment of the present invention, wherein the R y and R z At least one of them is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, and combinations thereof; the rest of R y and R z Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted aryl having 6 to 20 carbon atoms, and combinations thereof.

[0116] According to one embodiment of the present invention, each occurrence of Ar1 is identical or different and is selected from a substituted or unsubstituted aryl group having 10 to 20 carbon atoms.

[0117] According to one embodiment of the present invention, each occurrence of Ar1 is identically or differently selected from the group consisting of: naphthyl, biphenyl, phenanthrenyl, terphenyl, triphenylene, and combinations thereof; optionally, the above substituents can be partially or fully deuterated.

[0118] According to one embodiment of the present invention, the second organic material is selected from the group consisting of Compound B-1 to Compound B-40:

[0119]

[0120]

[0121]

[0122]

[0123] According to one embodiment of the present invention, the hydrogen in Compounds B-1 to B-40 can be partially or completely replaced by deuterium.

[0124] According to one embodiment of the present invention, the electron transport region is in direct contact with at least one of the first light-emitting layer and the second light-emitting layer.

[0125] According to one embodiment of the present invention, the electron transport region is disposed on a side of the first light-emitting layer close to the cathode and is in direct contact with the first light-emitting layer.

[0126] According to one embodiment of the present invention, the electron transport region is disposed on a side of the second light-emitting layer close to the cathode and is in direct contact with the second light-emitting layer.

[0127] According to one embodiment of the present invention, the device is a single-layer device, the first light-emitting layer is close to the anode and emits light with a first peak wavelength, the second light-emitting layer is close to the cathode and emits light with a second peak wavelength, and the electron transport region is between the second light-emitting layer and the cathode.

[0128] According to one embodiment of the present invention, the device is a stacked device, comprising a charge generation layer, wherein the charge generation layer is disposed between a first light-emitting layer and a second light-emitting layer.

[0129] According to one embodiment of the present invention, the charge generation layer includes a metal layer (n-type charge generation layer) and a buffer layer (p-type charge generation layer).

[0130] According to one embodiment of the present invention, the device is a stacked device, the first light-emitting layer is close to the anode and emits light containing a first peak wavelength, the second light-emitting layer is close to the cathode and emits light containing a second peak wavelength, a charge generation layer is arranged between the first light-emitting layer and the second light-emitting layer, the electron transport region is between the first light-emitting layer and the charge generation layer, and / or the electron transport region is between the second light-emitting layer and the cathode.

[0131] According to one embodiment of the present invention, the device is a stacked device, the first light-emitting layer is close to the anode and emits light containing a first peak wavelength, the second light-emitting layer is close to the cathode and emits light containing a second peak wavelength, the first peak wavelength is greater than the second peak wavelength, and the electron transport region is between the second light-emitting layer and the cathode.

[0132] According to one embodiment of the present invention, the device is a stacked device, the first light-emitting layer is close to the anode and emits light containing a first peak wavelength, the second light-emitting layer is close to the cathode and emits light containing a second peak wavelength, the first peak wavelength is smaller than the second peak wavelength, and the electron transport region is between the first light-emitting layer and the charge generation layer.

[0133] According to one embodiment of the present invention, at least one intermediate organic layer is included between the first organic layer and the second light-emitting layer.

[0134] According to one embodiment of the present invention, the intermediate organic layer is a hole blocking layer.

[0135] According to an embodiment of the present invention, one of the first peak wavelength and the second peak wavelength is between 450 nm and 500 nm, and the other is between 500 nm and 650 nm.

[0136] According to an embodiment of the present invention, the first organic material accounts for 0.1% to 60% of the weight of the entire first organic layer.

[0137] According to an embodiment of the present invention, the first organic material accounts for 0.1% to 50% of the weight of the entire first organic layer.

[0138] According to an embodiment of the present invention, the first organic material accounts for 0.3% to 50% of the weight of the entire first organic layer.

[0139] According to an embodiment of the present invention, the first organic material accounts for 0.4% to 50% of the weight of the entire first organic layer.

[0140] According to an embodiment of the present invention, the first organic material accounts for 0.4% to 45% of the weight of the entire first organic layer.

[0141] According to one embodiment of the present invention, the organic electroluminescent device is a top-emitting device.

[0142] According to one embodiment of the present invention, the anode is selected from the group consisting of Ti, Ni, Pt, Ag, Cr, MoOx, ITO, and combinations thereof.

[0143] According to one embodiment of the present invention, the organic electroluminescent device emits white light.

[0144] According to one embodiment of the present invention, the organic electroluminescent device emits cool white light.

[0145] According to an embodiment of the present invention, the color temperature of the cool white light is between 6000K and 11000K.

[0146] According to an embodiment of the present invention, the color temperature of the cool white light is between 6000K and 8000K.

[0147] According to one embodiment of the present invention, a display device is disclosed, which includes the organic electroluminescent device shown in any of the above embodiments.

[0148] According to one embodiment of the present invention, the display device includes a silicon substrate, and the organic electroluminescent device is disposed on the silicon substrate.

[0149] According to one embodiment of the present invention, the display device is a silicon-based microdisplay device.

[0150] Combination with other materials

[0151] The materials described herein for use in specific layers of organic light-emitting devices can be used in combination with various other materials present in the device. Combinations of these materials are described in detail in U.S. Patent Application No. US2016 / 0359122A1, paragraphs 0132-0161, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein 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.

[0152] The materials described herein as being useful in specific layers of an organic light-emitting device can be used in combination with a variety of other materials present in the device. For example, the compounds disclosed herein can be used in combination with a variety of light-emitting dopants, hosts, transport layers, barrier layers, injection layers, electrodes, and other layers that may be present. The combination of these materials is described in detail in paragraphs 0080-0101 of U.S. patent application US2015 / 0349273A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0153] In the device embodiments, device characteristics are also tested using conventional equipment in the art (including but not limited to evaporation machines produced by Angstrom Engineering, optical testing systems and life testing systems produced by Suzhou Fushida, and ellipsometers produced by Beijing Liangtuo) using methods familiar to those skilled in the art. Since those skilled in the art are familiar with the use of the aforementioned equipment, testing methods, and other related content and are able to reliably and unaffectedly obtain inherent data of the samples, such relevant content will not be further elaborated in this patent.

[0154] The preparation method of the organic electroluminescent device of the present invention is not limited. The preparation method of the following embodiment is only an example and should not be construed as limiting. Those skilled in the art can reasonably improve the preparation method of the following embodiment based on existing technology. For example, the ratio of the various materials in the light-emitting layer is not particularly limited. Those skilled in the art can reasonably select within a certain range based on existing technology. For example, based on the total weight of the light-emitting layer materials, the host material can account for 70%-99%, and the light-emitting material can account for 1%-30%; or the host material can account for 75%-99%, and the light-emitting material can account for 1%-25%. In addition, the host material can be one or two materials, wherein the ratio of the two host materials to the host material can be 99:1 to 1:99; or, the ratio can be 80:20 to 20:80. In the device embodiments, the device characteristics are also tested using conventional equipment in the art (including but not limited to evaporation machines produced by Angstrom Engineering, optical testing systems and life testing systems produced by Suzhou Fushida, and ellipsometers produced by Beijing Liangtuo, etc.) using methods familiar to those skilled in the art.

[0155] In the present invention, the first light-emitting layer emits light having a first peak wavelength, and the second light-emitting layer emits light having a second peak wavelength. For easier measurement, the first peak wavelength and the second peak wavelength are defined as the maximum emission wavelength (λ) in the photoluminescence spectrum of the light-emitting material used in the light-emitting layer. max-PL ). When there is only one luminescent material in the first luminescent layer or the second luminescent layer, the λ of the luminescent material used in the first luminescent layer and the second luminescent layer is max-PLThese are the corresponding first peak wavelength and second peak wavelength. When the first light-emitting layer comprises multiple light-emitting materials, the first light-emitting layer can emit light with multiple peak wavelengths (one light-emitting material emits light with one peak wavelength); or when the second light-emitting layer comprises multiple light-emitting materials, the second light-emitting layer can emit light with multiple peak wavelengths. When the maximum peak wavelength in the first light-emitting layer is greater than the maximum peak wavelength in the second light-emitting layer, the maximum peak wavelength in the first light-emitting layer is determined as the first peak wavelength, and the minimum peak wavelength in the second light-emitting layer is determined as the second peak wavelength. When the maximum peak wavelength in the first light-emitting layer is less than the maximum peak wavelength in the second light-emitting layer, the minimum peak wavelength in the first light-emitting layer is determined as the first peak wavelength, and the maximum peak wavelength in the second light-emitting layer is determined as the second peak wavelength.

[0156] In the present invention, the maximum emission wavelength (λ max-PL )The test method is as follows:

[0157] The photoluminescence spectrum (PL) data of the test compound was measured using a Lingguang F98 fluorescence spectrophotometer produced by Shanghai Lingguang Technology Co., Ltd. The test compound was dissolved in toluene solvent to prepare 1×10 -6 mol / L concentration of the solution, nitrogen was passed through the prepared test solution to remove oxygen for 5 minutes, the test solution was placed in a quartz sample tube and excited with 350nm wavelength light at room temperature (298K) and its emission spectrum was measured. The emission spectrum has a maximum emission wavelength λ max-PL .

[0158] As an example, the maximum emission wavelength λ of the photoluminescence spectrum of the following compound was measured by the above method: max-PL , the specific results are shown in Table 1:

[0159] Table 1 Maximum emission wavelength λ of the compounds max-PL

[0160] Compound number <![CDATA[λ max-PL (nm)]]> Compound GD 529 Compound RD 630 Compound BD 448

[0161] The specific structures of compound GD, compound RD and compound BD are:

[0162]

[0163] For device embodiments 1-3 of the present invention, the luminescent materials used in the first luminescent layer are compound GD and compound RD, so the peak wavelengths of light emitted by the first luminescent layer are 529 nm and 630 nm, respectively; the luminescent material used in the second luminescent layer is compound BD, so the peak wavelength of light emitted by the second luminescent layer is 448 nm; in this case, the first peak wavelength is 630 nm, and the second peak wavelength is 448 nm.

[0164] Device Examples

[0165] Device Example 1: Prepare a stacked organic electroluminescent device, the structural diagram of which is shown in FIG. Figure 2 shown.

[0166] First, a 0.7 mm thick glass substrate with a pre-patterned The thick titanium (Ti) is used as the anode 101. The substrate is then dried in a glove box to remove moisture and placed on a holder and transferred into a vacuum chamber. The organic layer specified below is placed in a vacuum of about 1×10 -6 Torr's case The anode layer was sequentially deposited by vacuum thermal evaporation at a rate of: first, compound HT and compound HI were simultaneously deposited as the first hole injection layer (HIL, weight ratio 97:3, )102, the evaporated compound HT is used as the first hole transport layer (HTL, )103, evaporate compound A-3 to serve as the first electron blocking layer (EBL, ) 104, and then simultaneously evaporated compound B-29, compound GD and compound RD as the first light-emitting layer (EML, weight ratio 79.5:20:0.5, )105, evaporate compound H1 as the first hole blocking layer (HBL, ) 106, evaporation compound B-29 and Liq co-deposited as the first electron transport layer (ETL, weight ratio 40:60, )107, evaporate Yb as n-type charge generation layer (n-CGL, )108, evaporation compound HI is a buffer layer 109, evaporating compound HT and compound HI as the second hole injection layer (HIL, weight ratio 97:3, )110, the evaporated compound HT is used as the second hole transport layer (HTL, )111, evaporate compound A-3 to serve as the second electron blocking layer (EBL, )112, and then simultaneously evaporated compound H2, compound A-3 and compound BD as the second light-emitting layer (EML, weight ratio 73:25:2, )113, evaporate compound ET1 as the second hole blocking layer (HBL, ) 114, co-evaporation compound B-29, Liq and compound A-3 as the second electron transport layer (ETL, weight ratio 39.8:59.7:0.5, )115, evaporate Yb as electron injection layer (EIL, )116, evaporated metal Mg and Ag as cathode (Cathode, weight ratio 10:90, )117, and finally evaporated compound CPL (the CPL material is selected to have a refractive index of about 1.95 at 630nm, and the refractive index is obtained by evaporating a CPL material with a thickness of 30nm on a silicon wafer using an ellipsometer model ESNano of Beijing Liangtuo Technology Co., Ltd.) as a capping layer (CPL, ) 118. The device was then transferred back to the glove box and encapsulated with a glass cover slip to complete the device.

[0167] Device Comparative Example 1: The preparation method is the same as that of Example 1, except that the compound ET and Liq are simultaneously evaporated as the second electron transport layer (ETL, weight ratio 40:60, ).

[0168] Device Comparative Example 2: The preparation method is the same as that of Example 1, except that compound B-29 and Liq are simultaneously evaporated as the second electron transport layer (ETL, weight ratio 40:60, ).

[0169] Device Comparative Example 3: The preparation method is the same as that of Example 1, except that compound B-29, Liq and compound H3 are simultaneously evaporated as the second electron transport layer (ETL, weight ratio 39.8:59.7:0.5, ).

[0170] The detailed device layer structures and thicknesses are shown in the table below. Layers containing more than one material are obtained by doping the different compounds in the stated weight ratios.

[0171] Table 2 Partial device structures of device embodiment 1 and comparative examples 1-3

[0172]

[0173]

[0174] The material structure used in the device is shown below:

[0175]

[0176]

[0177] At 1000cd / m 2The CIE values, voltage, and external quantum efficiency (EQE) of Example 1 and Comparative Examples 1-3 were measured. To more intuitively demonstrate the data comparison, the voltage and external quantum efficiency of Comparative Example 2 were set to 1.00, and the voltages and external quantum efficiencies of Example 1, Comparative Example 1, and Comparative Example 3 were converted relative to Comparative Example 2. After obtaining the CIE values, the color temperature (CCT) data were calculated using formula (1). The relevant data are shown in Table 3.

[0178] Formula (1):

[0179]

[0180] Table 3 Device data

[0181] Part Number CIE(x,y) Voltage EQE CCT(K) Example 1 0.292,0.364 0.99 1.14 7237 Comparative Example 1 0.255,0.255 1.04 0.95 18179 Comparative Example 2 0.296,0.370 1.00 1.00 6993 Comparative Example 3 0.250,0.252 1.02 1.00 20334

[0182] discuss:

[0183] Electron transport layers in the prior art typically contain at least one material that effectively conducts electrons (an electron transport material, typically an N-type material). Comparative Example 1 used the commercially available electron transport layer material compound ET in its second electron transport layer, while Comparative Example 2 used the N-type material compound B-29, commonly used in electron transport layers in the prior art. Compared to Comparative Examples 1 and 2, Example 1 significantly improved the EQE by 19% and 14%, respectively, by introducing the first organic material, p-type compound A-3, into the second electron transport layer, while maintaining a similar or even further reduced voltage. The fact that the device of the present invention can achieve such a significant improvement in device efficiency by introducing a minimal amount of the first organic material into the second electron transport layer is surprising. Furthermore, without changing the first and second light-emitting layers, Example 1 achieved color coordinates of (0.292, 0.364), showing minimal color coordinate shift compared to Comparative Example 2, which did not add the first organic material, maintaining color coordinate stability. Furthermore, Example 1 achieved a color temperature of 7237K, demonstrating an excellent cool white color temperature.

[0184] The above data proves that the organic electroluminescent device of the present invention, by introducing a first organic material, a p-type material, into the first organic layer included in the electron transport region, can more accurately control the carrier balance, obtain better overall device performance, have a higher EQE and lower voltage, and exhibit an excellent cool white light color temperature, thereby being able to meet excellent cool white light standards.

[0185] Comparative Example 3 introduces a commercial p-type material compound H3 into the second electron transport layer. However, surprisingly, compared with Comparative Example 3, Example 1 not only improves the EQE by 14%, but also reduces the voltage by a further 3%. At the same time, the color temperature of Example 1 is 7237K, showing an excellent cool white light color temperature, while the color temperature of Comparative Example 3 is as high as 20334K, showing a more extreme blue light color temperature. This shows that compared with p-type materials with other structures, the application of the first organic material represented by the specific structure of Formula 1 in the first organic layer of the organic electroluminescent device of the present invention can achieve better overall device performance, with higher EQE and lower voltage, while also effectively controlling the color temperature, showing an excellent cool white light color temperature.

[0186] Device Example 2: Prepare a single-layer organic electroluminescent device, the structural diagram of which is shown in FIG. Figure 3 shown.

[0187] First, a 0.7 mm thick glass substrate is used with a pre-patterned The thick titanium (Ti) is used as the anode 201. The substrate is then dried in a glove box to remove moisture and placed on a holder and transferred into a vacuum chamber. The organic layer specified below is placed in a vacuum of about 1×10 -6 Torr's case The anode layer was deposited sequentially by vacuum thermal evaporation at a rate of: first, compound HT and compound HI were simultaneously deposited as a hole injection layer (HIL, weight ratio 97:3, )202, the evaporated compound HT is used as a hole transport layer (HTL, )203, and then simultaneously evaporated compound B-29, compound GD and compound RD as the first light-emitting layer (EML, weight ratio 92.6:7:0.4, )204, evaporate compound A-3 as a blue light functional layer (BFL, )205, and then simultaneously evaporated compound H2, compound A-3 and compound BD as the second light-emitting layer (EML, weight ratio 73:25:2, )206, evaporate compound ET1 as hole blocking layer (HBL, )207, co-evaporation compound B-29, Liq and compound A-3 as an electron transport layer (ETL, weight ratio 39.8:59.7:0.5, )208, evaporate Yb as electron injection layer (EIL, )209, evaporated metal Mg and Ag as cathode (Cathode, weight ratio 10:90, )210, and finally evaporate compound CPL as a capping layer (CPL, )211.

[0188] Device Comparative Example 4: The preparation method is the same as that of Example 2, except that compound ET and Liq are simultaneously evaporated as the electron transport layer (ETL, weight ratio 40:60, ).

[0189] Table 4 Partial device structures of device embodiment 2 and comparative example 4

[0190]

[0191] At 1000cd / m 2 The CIE values, voltage, and external quantum efficiency (EQE) of Example 2 and Comparative Example 4 were measured. To more intuitively demonstrate the data comparison, the voltage and external quantum efficiency of Comparative Example 4 were set to 1.00, and the data of Example 2 was converted relative to Comparative Example 4. After obtaining the CIE values, the color temperature (CCT) data was calculated using formula (1). The relevant data are shown in Table 5.

[0192] Table 5 Device data

[0193] Part Number CIE(x,y) Voltage EQE CCT(K) Example 2 0.310,0.363 0.88 0.99 6421 Comparative Example 4 0.308,0.359 1.00 1.00 6534

[0194] Similarly, the device of the present invention also exhibits excellent device performance when it is a single-layer device. Compared with Comparative Example 4 in which a commercial electron transport layer material compound ET is used in the electron transport layer, Example 2 introduces the first organic material p-type material compound A-3 into the electron transport layer, and its voltage is significantly reduced by 12% compared with Comparative Example 4, while still maintaining excellent performance in terms of EQE. In addition, we can see that the color coordinates of Example 2 are (0.310, 0363), and the color coordinates of Comparative Example 4 are (0.308, 0.359), the color coordinate offset is very small, and the color temperature of Example 2 is 6421K, and the color temperature of Comparative Example 4 is 6534K, with a difference of only 113K. This difference is generally considered to be small and not enough to cause obvious visual perception. Therefore, this also shows that the device of the present invention can obtain excellent comprehensive device performance by introducing the first organic material into the first organic layer, and maintains excellent cold white light characteristics.

[0195] Silicon substrates are widely used in the microdisplay field, primarily due to their comprehensive advantages, including excellent dimensional compatibility, electronic properties, and stability. Therefore, to better meet the requirements of commercial products, we have fabricated the organic electroluminescent device of the present invention on a silicon substrate, demonstrating that the device can effectively improve color temperature, thereby achieving a more ideal white light effect. The following device examples and their data are provided to demonstrate this:

[0196] Device Example 3: The preparation method is the same as that of Example 1, except that a layer of Silicon dioxide as a silicon substrate, and patterned on it Thick titanium (Ti) was used as the anode, and compound A-3 and Liq were simultaneously evaporated as the second electron transport layer (ETL, weight ratio 40:60, ).

[0197] Device Comparative Example 5: The preparation method is the same as that of Example 3, except that compound B-29 and Liq are simultaneously evaporated as the second electron transport layer (ETL, weight ratio 40:60, ).

[0198] The detailed device layer structure and thickness are shown in the table below. For layers using more than one material, the different compounds are doped in the stated weight ratios.

[0199] Table 6 Partial device structures of device embodiment 3 and comparative example 5

[0200]

[0201] At 1000cd / m 2 The CIE values ​​of Example 3 and Comparative Example 5 were measured. After obtaining the CIE values, the color temperature (CCT) data was calculated using formula (1).

[0202] Table 7 Device data

[0203] Part Number CIE(x,y) CCT(K) Example 3 0.292,0.259 10396 Comparative Example 5 0.247,0.217 59691

[0204] The second electron transport layer in Comparative Example 5 uses the N-type material compound B-29 commonly used in electron transport layers in the prior art. Its color coordinates are (0.247, 0.217), which falls in the blue luminescent region. Its color temperature (CCT) is as high as 59691K, which is significantly deviated from the white light standard. Figure 4 The spectrum of Comparative Example 5 also shows that the blue light intensity of the device is too high, while the red and green light are weak. The first organic material compound A-3 represented by the structure of Formula 1 is used in the second electron transport layer in Example 3. Compound A-3 is doped in the ETL as a p-type material to help balance the carrier transport in the device. Compared with Comparative Example 5, its CIEx and CIEy color coordinates are offset by 0.045 and 0.042 respectively, resulting in an effective reduction of the color temperature (CCT) to 10396K, which significantly regulates the color temperature. According to Figure 5The spectrum of Example 3 also shows that the spectral intensity of red and green light is significantly improved compared to the spectrum of Comparative Example 5. This result shows that the organic electroluminescent device of the present invention improves the carrier balance in the device by introducing the first organic material represented by the structure of Formula 1 into the first organic layer included in the electron transport region, thereby bringing the color temperature and color coordinates closer to the cool white light standard.

[0205] These results demonstrate that the organic electroluminescent devices of the present invention, whether in stacked or single-layer devices, include a first organic material represented by Formula 1 in the first organic layer within the electron transport region, facilitating balanced carrier transport within the device, thereby achieving superior overall device performance, such as higher EQE and / or lower voltage. Furthermore, the organic electroluminescent devices of the present invention can effectively control color temperature, thereby achieving excellent cool white light standards.

[0206] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the present invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments and preferred embodiments described herein. Many of the materials and structures described herein can be replaced with other materials and structures without departing from the spirit of the present invention. It should be understood that the various theories regarding why the present invention works are not intended to be restrictive.

Claims

1. An organic electroluminescent device, comprising: anode; cathode; and a first light-emitting layer, a second light-emitting layer, and an electron transport region disposed between the anode and the cathode; The first light-emitting layer emits light having a first peak wavelength, the second light-emitting layer emits light having a second peak wavelength, and an absolute value of a difference between the first peak wavelength and the second peak wavelength is greater than or equal to 50 nm; The electron transport region includes a first organic layer, the first organic layer includes a first organic material, and the first organic material has a structure represented by Formula 1: in, Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof; Each occurrence of X is selected from CR x or N; Each occurrence of R is the same or different and represents mono-, poly-, or unsubstituted; R and R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; Adjacent substituents R and R x Can optionally be linked to form a ring. The organic electroluminescent device according to claim 1 , wherein the first organic material is a p-type material.

3. The organic electroluminescent device according to claim 1, wherein each occurrence of X is selected from CR x ; Preferably, the R and R x each occurrence being identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 20 carbon atoms, cyano, and combinations thereof; More preferably, the R and R x Each occurrence is identically or differently selected from the group consisting of: hydrogen, deuterium, fluorine, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, cyano, and combinations thereof.

4. The organic electroluminescent device according to claim 1, wherein the Ar is selected from a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms, or a combination thereof; Preferably, Ar is selected from the group consisting of: substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, and combinations thereof.

5. The organic electroluminescent device according to claim 1, wherein the first organic material is selected from the group consisting of Compound A-1 to Compound A-56: in, Optionally, hydrogen in the compounds A-1 to A-51, A-53 to A-56 may be partially or completely replaced by deuterium. The organic electroluminescent device according to claim 1 , wherein the first organic layer is an electron transport layer.

7. The organic electroluminescent device according to claim 1 or 6, wherein the first organic layer comprises at least one metal element or metal compound; preferably, the metal compound is selected from one or more of the group consisting of 8-hydroxyquinoline-lithium, 8-hydroxyquinoline-sodium, 8-hydroxyquinoline-potassium, di(8-hydroxyquinoline)-beryllium, di(8-hydroxyquinoline)-magnesium, di(8-hydroxyquinoline)-calcium, tri(8-hydroxyquinoline)-aluminum, tri(8-hydroxyquinoline)-gallium, and LiF; the metal element is selected from Yb or Li; more preferably, the first organic layer comprises 8-hydroxyquinoline-lithium.

8. The organic electroluminescent device of claim 1, wherein the device comprises a charge generation layer disposed between the first light-emitting layer and the second light-emitting layer.

9. The organic electroluminescent device according to claim 1 or 8, wherein the first light-emitting layer is close to the anode and emits light having a first peak wavelength, the second light-emitting layer is close to the cathode and emits light having a second peak wavelength, the first peak wavelength is greater than the second peak wavelength, and the electron transport region is between the second light-emitting layer and the cathode. 10 . The organic electroluminescent device according to claim 9 , wherein at least one intermediate organic layer is included between the first organic layer and the second light-emitting layer; preferably, the intermediate organic layer is a hole blocking layer. 11 . The organic electroluminescent device according to claim 1 , 8 or 9 , wherein one of the first peak wavelength and the second peak wavelength is between 450 nm and 500 nm, and the other is between 500 nm and 650 nm. 12 . The organic electroluminescent device according to claim 1 , wherein the first organic material accounts for 0.1% to 60% by weight of the entire first organic layer; preferably, between 0.3% and 50% by weight.

13. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device is a top-emitting device. The organic electroluminescent device according to claim 1 , wherein the organic electroluminescent device emits white light.

15. A display device comprising the organic electroluminescent device according to any one of claims 1 to 14. 16 . The display device according to claim 15 , wherein the display device comprises a silicon substrate, and the organic electroluminescent device is provided on the silicon substrate. The display device according to claim 16 , wherein the display device is a silicon-based microdisplay device.

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