Organic compound, organic light-emitting device and display device

Abstract

The invention relates to an organic compound, an organic light-emitting device and a display device. The organic compound has a structure represented by a general formula (1), the organic compound represented by the formula (1) has a low refractive index and can be used for forming a low-refractive-index covering layer, and when the low-refractive-index covering layer and a high-refractive-index covering layer are matched to form a covering layer structure of the organic light-emitting device, the light-emitting efficiency of the organic light-emitting device can be remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to an organic compound, an organic light emitting device and a display device. BACKGROUND

[0002] Organic Light Emitting Diode (OLED) devices are favored in many application fields such as main display screens due to their excellent display performance, and have made significant progress in the process of practical application. However, although the organic electroluminescence technology develops rapidly, it still faces many challenges, especially the demand for improving the external quantum efficiency (EQE). For OLED devices, the light-emitting quantum efficiency is not only a comprehensive embodiment of the performance of the device, but also a key standard for measuring the quality of the device.

[0003] In the related art, the light extraction efficiency of the OLED device is optimized by a capping layer (CPL). However, the organic material currently used for the capping layer generally has the problem of low light extraction efficiency, which limits the improvement of the light-emitting efficiency of the OLED device. SUMMARY The present application provides an organic compound, an organic light emitting device and a display device, which can effectively improve the light extraction efficiency of the capping layer and improve the light-emitting efficiency of the organic light emitting device.

[0004] The present application provides an organic compound, which has a structure represented by general formula (1): (1) wherein, R is independently selected from at least one of hydrogen, fluorine, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aromatic group.

[0005] In some embodiments, when R is selected from a substituted alkyl group or a substituted aromatic group, the substituent group is selected from an alkyl group or a fluorine-containing group.

[0006] In some embodiments, R is selected from at least one of hydrogen, fluorine, a methyl group, a trifluoromethyl group, a fluorine-substituted phenyl group, a methyl-substituted phenyl group, and a trifluoromethyl-substituted phenyl group.

[0007] In some embodiments, the organic compound is selected from any one of the following structures: .

[0008] In some embodiments, the organic compound has a refractive index ranging from 1.40 to 1.70 for light having a wavelength of 460 nm.

[0009] The present application also provides an organic light-emitting device, comprising: a first electrode; a light-emitting functional layer disposed on the first electrode; a second electrode disposed on a side of the light-emitting functional layer away from the first electrode; and a cover layer disposed on a side of the second electrode away from the light-emitting functional layer; wherein the material of the cover layer comprises at least one organic compound as described above.

[0010] In some embodiments, the cover layer comprises a first sub-cover layer and a second sub-cover layer, the first sub-cover layer being located between the second electrode and the second sub-cover layer; wherein the material of the first sub-cover layer comprises at least one organic compound, and the refractive index of the first sub-cover layer is less than that of the second sub-cover layer. In some embodiments, the first sub-cover layer has a refractive index of light with a wavelength of 460 nm less than or equal to 1.60, and the second sub-cover layer has a refractive index of light with a wavelength of 460 nm greater than or equal to 1.85. In some embodiments, the difference between the refractive index of light with a wavelength of 460 nm of the second sub-cover layer and the refractive index of light with a wavelength of 460 nm of the first sub-cover layer is greater than or equal to 0.3. In some embodiments, the difference between the refractive index of light with a wavelength of 460 nm of the first sub-cover layer and the refractive index of light with a wavelength of 620 nm of the first sub-cover layer is less than or equal to 0.3.

[0011] The present application also provides a display device comprising the organic light-emitting device as described above.

[0012] The present application provides an organic compound, an organic light-emitting device and a display device. In the organic compound of the present application, two arylamine structures are connected by a diphenylpropane structure, and the two benzene rings are connected by a structure similar to propane [-CH-(CH3)2], so that the conjugated system is interrupted, and the degree of delocalization of π electrons is much lower than that of fused rings or conjugated polymers, so that the electron cloud has a weak response to an applied electric field, and the macroscopic performance is a low refractive index. In addition, the methyl and methylene in the propane bridge are in a tetrahedral configuration, so that the whole molecule is "bent" rather than planar stacking, and a large amount of free volume can be retained after crystallization or evaporation into a film. Such low density results in a small number of polarizable particles per unit volume, which synergistically contributes to a low refractive index. Therefore, the organic compound of the present application has a low refractive index, and can be used to form a low refractive index cover layer. When the low refractive index cover layer is combined with a high refractive index cover layer to form a cover layer structure and applied to an organic light-emitting device, the luminous efficiency of the device can be significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0014] Figure 1 is a structural schematic diagram of an organic light-emitting device provided by an embodiment of the present application; Figure 2 is a structural schematic diagram of another organic light-emitting device provided by an embodiment of the present application; Figure 3 is a nuclear magnetic hydrogen spectrum of compound M4 provided by an embodiment of the present application.

[0015] EXPLANATION OF REFERENCE NUMERALS: 100 - Organic light emitting device; 110 - Driving substrate; 120 - First electrode; 130 - Light emitting functional layer; 131 - Hole injection layer; 132 - Hole transport layer; 133 - Electron blocking layer; 134 - Light emitting layer; 135 - Hole blocking layer; 136 - Electron transport layer; 137 - Electron injection layer; 140 - Second electrode; 150 - Cover layer; 151 - First sub-cover layer; 152 - Second sub-cover layer; 160 - Protection layer; 170 - Encapsulation layer. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0017] In the present application, "n@460 nm" refers to the refractive index of the material relative to vacuum for blue light of 460 nm wavelength; "n@525 nm" refers to the refractive index of the material relative to vacuum for green light of 530 nm wavelength; "n@620 nm" refers to the refractive index of the material relative to vacuum for red light of 620 nm wavelength.

[0018] The present application provides an organic compound, which has a structure represented by general formula (1): (1) wherein, R is independently selected at each occurrence from at least one of hydrogen, fluorine, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aromatic group; It should be noted that in the structure represented by general formula (1), R at different positions can be selected from the same group or different groups.

[0019] In some embodiments, R is selected from at least one of hydrogen, fluorine, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, and a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms.

[0020] In some embodiments, when R is selected from a substituted alkyl group or a substituted aromatic group, the substituent is selected from an alkyl group or a fluorine-containing group.

[0021] Further, the substituent is selected from at least one of fluorine, an alkyl group having 1 to 5 carbon atoms, and a fluorine-substituted alkyl group having 1 to 5 carbon atoms.

[0022] In some embodiments, R is selected from at least one of hydrogen, fluorine, methyl, trifluoromethyl, fluorine-substituted phenyl, methyl-substituted phenyl, trifluoromethyl-substituted phenyl.

[0023] In some embodiments, the organic compound is selected from any one of the following structures: .

[0024] In some embodiments, the organic compound has a low refractive index, and the refractive index of the organic compound for light with a wavelength of 460 nm (blue light) ranges from 1.40 to 1.70; preferably, the refractive index of the organic compound for light with a wavelength of 460 nm ranges from 1.40 to 1.60. For example, the refractive index of the organic compound for light with a wavelength of 460 nm can be 1.40, 1.45, 1.50, 1.55, or 1.60, but is not limited thereto.

[0025] In the present application, two arylamine structures in the organic compound represented by general formula (1) are connected through a diphenylpropane structure, wherein two benzene rings are connected in a similar structure of propane [-CH-(CH3)2], so that the conjugated system is interrupted, and the overall π electron delocalization degree is much lower than that of a fused ring or a conjugated polymer, so that the electron cloud has a weak response to an applied electric field, and the macroscopic performance is a low refractive index. In addition, the methyl and methylene in the propane bridge are in a tetrahedral configuration, so that the whole molecule is "bent" rather than planar stacking, and a large amount of free volume can be retained after crystallization or evaporation into a film. Such low density results in a small number of polarizable particles per unit volume, which cooperatively contributes to a low refractive index. Therefore, the organic compound of the present application has a low refractive index, and can be used to form a low refractive index cover layer. When the low refractive index cover layer using the organic compound is combined with a high refractive index cover layer and applied to an organic light emitting device, the light emitting efficiency of the organic light emitting device can be significantly improved.

[0026] The present application also provides an organic light emitting device 100, which is described below Figure 1 The organic light emitting device 100 includes a first electrode 120, a light emitting functional layer 130, a second electrode 140, and a cover layer 150. The light emitting functional layer 130 is disposed on the first electrode 120; the second electrode 140 is disposed on the side of the light emitting functional layer 130 away from the first electrode 120; the cover layer 150 is disposed on the side of the second electrode 140 away from the light emitting functional layer 130; wherein the material of the cover layer 150 includes at least one organic compound represented by formula (1) as described above. The use of the organic compound represented by formula (1) to form the cover layer in the present application can significantly improve the light extraction efficiency of the cover layer, and further improve the light emitting efficiency of the organic light emitting device.

[0027] In some embodiments, referring to Figure 1 The organic light emitting device 100 further includes a driving substrate 110, which is disposed on the side of the first electrode 120 away from the light emitting functional layer 130, and is used to provide a supporting function and a driving voltage to realize the light emitting of the light emitting functional layer 130.

[0028] The driving substrate includes a substrate and a driving circuit disposed on the substrate. The substrate can be glass or flexible polyimide film; the substrate can be a transparent plastic substrate or a non-transparent material substrate such as a silicon or stainless steel substrate, but is not limited thereto. The driving circuit includes thin film transistors, capacitors, conductive wires, etc. Different driving substrates have different mechanical strength, thermal stability, transparency, surface smoothness, and waterproofness, and their use directions are different according to their properties. The specific selection can be based on the performance requirements of the organic light emitting device, and the present application is not limited thereto.

[0029] In the present application, one of the first electrode and the second electrode is an anode, and the other is a cathode. For example, the first electrode can be an anode, and the second electrode can be a cathode.

[0030] In some embodiments, the first electrode can be a reflective electrode, such as a reflective film formed of silver (Ag), magnesium (Mg), aluminum (Al), gold (Au), nickel (Ni), chromium (Cr), or an alloy thereof; or an electrode formed of a combination of a reflective film and a transparent or semi-transparent electrode, such as a transparent or semi-transparent electrode layer having a high work function and formed on a reflective film, wherein the transparent or semi-transparent electrode layer can be formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum zinc oxide (AZO), indium gallium oxide (IGO), indium oxide (In2O3), or tin oxide (SnO2), or a combination of a metal and an oxide, such as ITO / Ag / ITO, IGO / Al / IGO, or AZO / Ag / AZO. Light emitted by the light-emitting functional layer can be reflected by the first electrode toward the second electrode, and then emitted by the second electrode. The first electrode can be formed by sputtering, ion plating, vacuum evaporation, spin coating, electron beam evaporation, or chemical vapor deposition (CVD), and is preferably formed by sputtering. The thickness of the first electrode layer depends on the material used, and the thickness of the first electrode layer ranges from 5 nm to 1 μm, preferably from 10 nm to 1 μm, more preferably from 10 nm to 500 nm, particularly preferably from 10 nm to 300 nm, and most preferably from 10 nm to 200 nm.

[0031] In some embodiments, the second electrode can be a transparent electrode or a semi-transparent electrode, such as a thin film having a low work function made of lithium, calcium, lithium fluoride / calcium, lithium fluoride / aluminum, aluminum, silver, magnesium, or an alloy thereof. Further, the second electrode layer can be made of an alloy including silver and at least one metal including aluminum, platinum, ytterbium, chromium, or magnesium, wherein the weight ratio of silver in the alloy can be the same as or greater or less than the weight of the other metal. For example, the second electrode layer can be formed of a silver-magnesium alloy, wherein the mass ratio of silver to magnesium can be from 90:10 to 10:90. Alternatively, the second electrode layer can be formed of an alloy including at least one metal such as silver, gold, platinum, copper, nickel, or tungsten, and at least one metal such as ytterbium, indium, magnesium, or chromium. A film formed of these metals can form a transparent or semi-transparent electrode by adjusting the thickness of the film, and thus light generated by the light-emitting functional layer can be emitted through the second electrode layer. The thickness of the second electrode layer ranges from 5 nm to 20 nm. The second electrode can be formed by vacuum evaporation or the like.

[0032] In the present application, the light-emitting functional layer can include one or more film layers, and the light-emitting functional layer includes at least a light-emitting layer. The thickness of the light-emitting functional layer ranges from 50 nm to 1000 nm.

[0033] In some embodiments, the light-emitting functional layer can include only the light-emitting layer.

[0034] In some embodiments, when the light-emitting functional layer includes multiple film layers, the light-emitting functional layer can include at least one of a hole transport layer, a hole injection layer, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. in addition to the light-emitting layer. When the first electrode is an anode and the second electrode is a cathode, a hole transport region is formed between the first electrode and the light-emitting layer, and an electron transport region is formed between the second electrode and the light-emitting layer; wherein the first electrode and the light-emitting layer can include at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, and the second electrode and the light-emitting layer can include at least one of a hole blocking layer, an electron transport layer, and an electron injection layer. When the first electrode is a cathode and the second electrode is an anode, an electron transport region is formed between the first electrode and the light-emitting layer, and a hole transport region is formed between the second electrode and the light-emitting layer; wherein the first electrode and the light-emitting layer can include at least one of a hole blocking layer, an electron transport layer, and an electron injection layer, and the second electrode and the light-emitting layer can include at least one of a hole injection layer, a hole transport layer, and an electron blocking layer.

[0035] Specifically, please refer to Figure 2 For example, the first electrode 120 is an anode, and the second electrode 140 is a cathode. The light-emitting functional layer 130 includes a light-emitting layer 134, a hole injection layer 131, a hole transport layer 132, an electron blocking layer 133, a hole blocking layer 135, an electron transport layer 136, and an electron injection layer 137. The hole injection layer 131 is located on the side of the first electrode 120 away from the driving substrate 110. The hole transport layer 132 is located on the side of the hole injection layer 131 away from the first electrode 120. The electron blocking layer 133 is located on the side of the hole transport layer 132 away from the hole injection layer 131. The light-emitting layer 134 is located on the side of the electron blocking layer 133 away from the hole transport layer 132. The hole blocking layer 135 is located on the side of the light-emitting layer 134 away from the electron blocking layer 133. The electron transport layer 136 is located on the side of the hole blocking layer 135 away from the light-emitting layer 134. The electron injection layer 137 is located between the electron transport layer 136 and the second electrode 140.

[0036] In some embodiments, the light-emitting functional layer can be formed by small molecule organic materials or high molecular materials. The light-emitting functional layer can be formed by vacuum evaporation, solution spin coating, screen printing, or inkjet printing.

[0037] In some embodiments, the material of the light-emitting layer can include a host material and a dopant material. The host material needs to have bipolar charge transport characteristics and appropriate energy levels, and can effectively transfer the excitation energy generated by the recombination of electrons and holes to the guest light-emitting material, i.e., the dopant material. The host material can be a diphenylstyryl arylene derivative, a bisphenylstyrene derivative, a carbazole derivative, a triarylamine derivative, an anthracene derivative, a pyrene derivative, a triazine derivative, a xanthone derivative, a triphenylene derivative, a triazine derivative, a hexa-peri-hexabenzocoronene derivative, or bis(2-methyl-8-quinolinato)(p-phenylphenolato) aluminum (BAlq), etc. The dopant material can be a fluorescent material, a delayed fluorescence (TADF) material, or a phosphorescent material, etc.

[0038] In some embodiments, in order to improve the light-emitting efficiency of the organic light-emitting device, the light-emitting layer can include one or more dopant materials, which can be one of a fluorescent material, a delayed fluorescence (TADF) material, or a phosphorescent material, or a combination of different fluorescent materials, delayed fluorescence (TADF) materials, or phosphorescent materials.

[0039] In some embodiments, the light-emitting layer can include one or more sub-light-emitting layers of different colors, including at least one of a red sub-light-emitting layer, a green sub-light-emitting layer, and a blue sub-light-emitting layer, wherein the red sub-light-emitting layer includes a red light-emitting material, the green sub-light-emitting layer includes a green light-emitting material, and the blue sub-light-emitting layer includes a blue light-emitting material. In order to adjust the effective combination of carrier charges in the light-emitting layer, the film thickness of the light-emitting layer can be adjusted as needed, or different light-emitting layers can be alternately stacked and combined as needed, and a charge blocking layer with different functions can also be added between adjacent light-emitting layers, etc.

[0040] In some embodiments, the light-emitting layer can be a single light-emitting material layer, or a composite light-emitting material layer stacked together in a horizontal or vertical direction. The light-emitting layer can be selected from the following configurations: (1) a single light-emitting material layer; (2) a combination of a blue light-emitting material layer and any one of a green, yellow, or red light-emitting material layer, regardless of the order; (3) a combination of a blue light-emitting material layer and any two of a green, yellow, or red light-emitting material layer, regardless of the order; (4) a horizontal arrangement of a blue light-emitting material layer, a green light-emitting material layer, and a red light-emitting material layer.

[0041] In some embodiments, the materials of the hole injection layer, the hole transport layer, and the electron blocking layer can be any material selected from known related materials for OLED organic light-emitting devices.

[0042] In some embodiments, at least one of the hole injection layer and the hole transport layer can further comprise a charge generation material for improving conductivity, which can be a p-dopant. The p-dopant can be a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethane (F4-TCNQ); or a hexaazatriphenylene derivative, such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN); or a cyclopropane derivative, such as 4,4',4''-((1E,1'E,1''E)-cyclopropane-1,2,3-trimethylenyltris(cyanocarbonyl))tris(2,3,5,6-tetrafluorobenzyl); or a metal oxide, such as tungsten oxide and molybdenum oxide, but not limited thereto.

[0043] In some embodiments, the triplet (T1) energy level of the electron blocking layer material is higher than the T1 energy level of the host material in the light-emitting layer, which can block the energy loss of the light-emitting layer material; the Highest Occupied Molecular Orbital (HOMO) energy level of the electron blocking layer material is between the HOMO energy level of the hole transport layer material and the HOMO energy level of the host material in the light-emitting layer, which facilitates the injection of holes from the anode into the light-emitting layer, while requiring the electron blocking layer material to have high hole mobility to facilitate hole transport and reduce the application power of the device; the Lowest Unoccupied Molecular Orbital (LUMO) energy level of the electron blocking layer material is higher than the LUMO energy level of the host material in the light-emitting layer, which plays a role in blocking electrons, i.e., the electron blocking layer material is required to have a wide band gap (Eg). Specifically, the electron blocking layer material can be a triarylamine derivative, a fluorene derivative, a spirofluorene derivative, a dibenzofuran derivative, or a carbazole derivative, etc. Among them, preferably, the triarylamine derivative is, for example, N4,N4-bis([1,1'-biphenyl]-4-yl)-N4'-phenyl-N4'-[1,1'4',1''-terphenyl]-4-yl-[1,1'-biphenyl]-4,4'-diamine; the spirofluorene derivative is, for example, N-([1,1'-diphenyl]-4-yl)-N-(9,9-dimethyl-9H-furan-2-yl)-9,9'-spirobifluorene-2-amine; the dibenzofuran derivative is, for example, N,N-di([1,1'-biphenyl]-4-yl)-3'-(dibenzo[b,d]furan-4-yl)-[1,1'-biphenyl]-4-amine, but not limited thereto.

[0044] In some embodiments, the material of the hole blocking layer and the electron transport layer is a material having electron transport property, and any material known to be used in OLED organic light emitting devices can be used. The material having electron transport property can be 1,3-bis[5'-(p-tert-butylphenyl)-1,3,4-oxadiazol-2'-yl]benzene, oxadiazole derivatives such as 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, triazole derivatives such as 3-(4'-tert-butylphenyl)-4-phenyl-5-(4"-biphenyl)-1,2,4-triazole, triazine derivatives, quinoline derivatives, quinoxaline derivatives, diphenoquinone derivatives, nitro-substituted xanthone derivatives, thiopyran dioxide derivatives, anthracenequinone dioxymethane derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthyl perylene, carbodiimides, xanthene derivatives, anthracenequinone dioxymethane derivatives, anthracene ketone derivatives, diphenyl styryl pyrazine derivatives, silacyclopentadiene derivatives, diazaphenanthrene derivatives, or imidazopyridine derivatives, and the like.

[0045] In the present application, the cover layer can be formed of an organic compound represented by formula (1), or an organic compound represented by formula (1) and an organic compound of an aromatic amine structure. The cover layer can be formed by a vacuum evaporation method, a solution spin coating, a screen printing, or an inkjet printing method, and the like.

[0046] In some embodiments, referring to Figure 1 , the cover layer 150 includes a first sub-cover layer 151 and a second sub-cover layer 152, the first sub-cover layer 151 is located between the second electrode 140 and the second sub-cover layer 152, and the refractive index of the first sub-cover layer 151 is less than the refractive index of the second sub-cover layer 152; wherein the material of the first sub-cover layer 151 includes at least one organic compound represented by formula (1).

[0047] In some embodiments, the second sub-cover layer includes an organic compound with high refractive index, for example, the material of the second sub-cover layer can include at least one of the following compounds, but is not limited to the following compounds: .

[0048] In the present application, the cover layer is a double cover layer structure composed of a first sub-cover layer with low refractive index and a second sub-cover layer with high refractive index. In the double cover layer structure, due to the refractive index difference between the second sub-cover layer with high refractive index and the first sub-cover layer with low refractive index, part of the light emitted by the light-emitting functional layer transmits through the cover layer, and the other part is reflected by the cover layer. In particular, at the interface between the second sub-cover layer with high refractive index and the first sub-cover layer with low refractive index, and at the interface between the second sub-cover layer with high refractive index and the encapsulation layer above it, the reflection of light is particularly obvious. The light reflected by the cover layer is reflected again at the second electrode and is enhanced in the process of repeated reflection. Therefore, the light can be repeatedly reflected between the interface between the second sub-cover layer with high refractive index and the first sub-cover layer with low refractive index, and the interface between the second sub-cover layer with high refractive index and the encapsulation layer above it, thereby recovering the light lost back to the surface of the device due to reflection. Therefore, the double cover layer structure composed of the first sub-cover layer with low refractive index and the second sub-cover layer with high refractive index is more conducive to improving the light extraction efficiency and further improving the light-emitting efficiency of the organic light-emitting device.

[0049] In the present application, the organic compound represented by formula (1) is used to form the first sub-cover layer, which can make the first sub-cover layer have a lower refractive index, and the combination with the second sub-cover layer with high refractive index can significantly improve the light extraction efficiency of the whole cover layer.

[0050] In some embodiments, the refractive index of the first sub-cover layer is less than or equal to 1.60, preferably less than or equal to 1.55, and further preferably less than or equal to 1.50, at 460 nm. The refractive index of the first sub-cover layer is less than or equal to 1.60, preferably less than or equal to 1.55, and further preferably less than or equal to 1.50, at 525 nm. The refractive index of the first sub-cover layer is less than or equal to 1.60, preferably less than or equal to 1.55, and further preferably less than or equal to 1.50, at 620 nm.

[0051] In some embodiments, the refractive index of the second sub-cover layer is greater than or equal to 1.85, preferably greater than or equal to 1.9, further preferably greater than or equal to 2.0, more preferably greater than or equal to 2.1, further preferably greater than or equal to 2.2, and more preferably greater than or equal to 2.3, at 460 nm. The refractive index of the second sub-cover layer is greater than or equal to 1.85, preferably greater than or equal to 1.9, further preferably greater than or equal to 2.0, more preferably greater than or equal to 2.1, and more preferably greater than or equal to 2.2, at 525 nm. The refractive index of the second sub-cover layer is greater than or equal to 1.8, preferably greater than or equal to 1.9, further preferably greater than or equal to 2.0, and more preferably greater than or equal to 2.1, at 620 nm.

[0052] In some embodiments, the difference between the refractive index of the first sub-covering layer for light with a wavelength of 460 nm and the refractive index of the second sub-covering layer for light with a wavelength of 460 nm can be greater than or equal to 0.3, preferably greater than or equal to 0.4, further preferably greater than or equal to 0.5, more further preferably greater than or equal to 0.6, still further preferably greater than or equal to 0.7, more preferably greater than or equal to 0.8, so as to reduce total reflection of light at the interface and improve light extraction efficiency.

[0053] In some embodiments, the difference between the refractive index of the first sub-covering layer for light with a wavelength of 460 nm and the refractive index of the first sub-covering layer for light with a wavelength of 620 nm is less than or equal to 0.3, so as to balance the light extraction efficiency of light of different colors and improve the overall light extraction efficiency of the organic light-emitting device.

[0054] In an embodiment, the refractive index of the first sub-covering layer is less than the refractive index of the second sub-covering layer, the refractive index of the first sub-covering layer for light with a wavelength of 460 nm is less than or equal to 1.60, the refractive index of the second sub-covering layer for light with a wavelength of 460 nm is greater than or equal to 1.85, and the difference between the refractive index of the first sub-covering layer for light with a wavelength of 460 nm and the refractive index of the second sub-covering layer for light with a wavelength of 460 nm is greater than or equal to 0.3, so as to improve light extraction efficiency.

[0055] In some embodiments, the optical band gap E g of the organic compound in the first sub-covering layer is greater than 3.0 eV, preferably greater than 3.5 eV. When the optical band gap E g of the organic compound is greater than the above range, it indicates that the material of the first sub-covering layer has a higher first singlet excited state energy level, and the absorption of the first sub-covering layer for visible light is weaker, the probability of light being absorbed by the first sub-covering layer during propagation in the device is lower, and the light is more easily extracted from the device, which is beneficial to improving the overall light extraction efficiency of the organic light-emitting device.

[0056] In some embodiments, the thickness of the covering layer ranges from 15 nm to 300 nm, preferably from 30 nm to 200 nm, more preferably from 40 nm to 100 nm, and most preferably from 50 nm to 80 nm. The thickness of the first sub-covering layer ranges from 1 nm to 150 nm, preferably from 5 nm to 100 nm, and more preferably from 10 nm to 50 nm; the thickness of the second sub-covering layer ranges from 1 nm to 150 nm, preferably from 10 nm to 100 nm, and more preferably from 20 nm to 80 nm. The thickness of the first sub-covering layer can be the same as or different from the thickness of the second sub-covering layer.

[0057] In some embodiments, please refer to Figure 2The organic light emitting device 100 further comprises a protective layer 160 disposed on the side of the capping layer 150 away from the light emitting functional layer 130 for protecting the capping layer 150. The protective layer 160 can be an inorganic material such as lithium fluoride (LiF), but is not limited thereto. The thickness of the protective layer 160 ranges from 20 nm to 400 nm, preferably from 30 nm to 200 nm, and more preferably from 40 nm to 100 nm, and in particular, the thickness of the protective layer 160 depends on the material used.

[0058] In some embodiments, referring to Figure 2 The organic light emitting device 100 further comprises an encapsulation layer 170 disposed on the side of the protective layer 160 away from the capping layer 150 to cover the protective layer 160, the capping layer 150 and the light emitting functional layer 130. The encapsulation layer 170 is used to prevent external substances such as moisture and oxygen from entering the organic layer of the organic light emitting device to avoid water and oxygen from entering and causing display abnormalities.

[0059] Further, the encapsulation layer 170 can comprise one or more film layers. For example, the encapsulation layer 170 can comprise a first encapsulation layer, a second encapsulation layer and a third encapsulation layer stacked together, the first encapsulation layer being an inorganic layer, the second encapsulation layer being an organic layer, and the third encapsulation layer being an inorganic layer; the material of the inorganic layer can be selected from at least one of Al2O3, SiO x N y , TiO2, SiO x and SiN x , wherein x and y are the same or different, x and y are greater than 0 and less than 10, preferably greater than 0 and less than 5, and more preferably greater than 0 and less than 3, and the inorganic layer can be prepared by a chemical vapor deposition (CVD) method; the material of the organic layer can be an encapsulation layer organic material for OLED organic light emitting devices known in the prior art, for example, the material of the organic layer can be at least one of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polystyrene (PS), a polymer derivative having a phenol group, an acryl-based polymer, an imide-based polymer, an aryl ether-based polymer, an amide-based polymer, a fluorine-based polymer, a p-xylene-based polymer or a vinyl alcohol-based polymer, and the organic layer can be solidified by UV curing.

[0060] The application also provides a display device comprising the organic light-emitting device as described above. The display device can be used in the fields of smart phones, tablet computers, smart wearable devices, televisions, virtual reality (VR), micro displays, and car central screens, but is not limited thereto.

[0061] The organic compounds and the organic light-emitting device of the present application are further described below through specific examples, but the present application is not limited to the following examples.

[0062] 1. Synthesis of organic compounds (1) Synthesis of compound M1:

[0063] Compound 1-1 (10 mmol), compound 1-2 (40 mmol), Pd2(dba)3 (0.2 mmol), X-phos (0.4 mmol) and sodium tert-butoxide (20 mmol) were dissolved in xylene solvent, stirred at 140°C under nitrogen atmosphere for 13 h. After the reaction system was cooled to room temperature, a portion of the solvent was removed by a rotary evaporator, then extracted with dichloromethane and water for 3 times. After separation, dried over MgSO4 and filtered, the solvent was removed under reduced pressure; the crude product was purified by column chromatography to obtain compound M1, with a yield of 86%, mass spectrum m / z [H + ]= 602. The elemental analysis test value was C, 77.75; H, 5.04; F, 12.62; N, 4.61.

[0064] (2) Synthesis of compound M2:

[0065] The synthesis method of compound M2 was referred to the above synthesis steps of compound M1, with a yield of 84%. Mass spectrum m / z [H + ]= 808. The elemental analysis test value was C, 62.77; H, 2.95; F, 30.56; N, 3.77.

[0066] (3) Synthesis of compound M3:

[0067] The synthesis method of compound M3 was referred to the above synthesis steps of compound M1, with a yield of 85%. Mass spectrum m / z [H + ]= 802. The elemental analysis test value was C, 64.35; H, 3.73; F, 28.44; N, 3.46.

[0068] (4) Synthesis of compound M4:

[0069] The synthesis of compound M4 was performed according to the above-mentioned procedure for synthesizing compound M1, with a yield of 82%. Mass spectrum m / z [H + ]=1074. The elemental analysis test values were C, 52.55; H, 2.47; F, 42.42; N, 2.62. The nuclear magnetic hydrogen spectrum of compound M4 is shown in Figure 2. Figure 3 .

[0070] (5) Synthesis of compound M5:

[0071] The synthesis of compound M5 was performed according to the above-mentioned procedure for synthesizing compound M1, with a yield of 84%. Mass spectrum m / z [H + ]=926. The elemental analysis test values were C, 50.58; H, 1.32; F, 45.13; N, 3.05.

[0072] (6) Synthesis of compound M6:

[0073] Synthesis of intermediate 6-3: Compound 6-1 (10 mmol), compound 6-2 (10 mmol), Pd2(dba)3(0.2 mmol), X-phos (0.4 mmol) and sodium tert-butoxide (20 mmol) were dissolved in toluene solvent, stirred at 120°C under nitrogen atmosphere for 7h. After the reaction system was cooled to room temperature, it was extracted with dichloromethane and water for 3 times. After separation, it was dried over MgSO4and filtered, and the solvent was removed under reduced pressure; the crude product was purified by column chromatography to obtain intermediate 6-3, with a yield of 87%, mass spectrum m / z [H + ]=359.

[0074] Synthesis of compound M6: Compound 6-3 (10 mmol), compound 6-4 (10 mmol), Pd2(dba)3(0.2 mmol), X-phos (0.4 mmol) and sodium tert-butoxide (20 mmol) were dissolved in toluene solvent, stirred at 120°C under nitrogen atmosphere for 13h. After the reaction system was cooled to room temperature, it was extracted with dichloromethane and water for 3 times. After separation, it was dried over MgSO4and filtered, and the solvent was removed under reduced pressure; the crude product was purified by column chromatography to obtain compound M6, with a yield of 83%, mass spectrum m / z [H +Elemental analysis test value: C, 56.73; H, 2.67; F, 37.52; N, 3.06.

[0075] (7) Synthesis of compound M7:

[0076] The synthesis method of intermediate 7-3 refers to the synthesis operation steps of intermediate 6-3 described above, and the yield is 57%. Mass spectrum m / z [H + ]= 395.

[0077] The synthesis method of compound M7 refers to the synthesis operation steps of compound M6 described above, and the yield is 84%. Mass spectrum m / z [H + ]=982. Elemental analysis test value: C, 52.58; H, 2.07; F, 42.52; N, 2.86.

[0078] (8) Synthesis of compound M8:

[0079] The synthesis method of intermediate 8-3 refers to the synthesis operation steps of intermediate 6-3 described above, and the yield is 67%. Mass spectrum m / z [H + ]=313.

[0080] The synthesis method of compound M8 refers to the synthesis operation steps of compound M6 described above, and the yield is 84%. Mass spectrum m / z [H + ]=818. Elemental analysis test value: C, 57.27; H, 2.25; F, 37.11; N, 3.40.

[0081] (9) Synthesis of compound M9:

[0082] The synthesis method of intermediate 9-3 refers to the synthesis operation steps of intermediate 6-3 described above, and the yield is 78%. Mass spectrum m / z [H + ]= 517.

[0083] The synthesis method of compound M9 refers to the synthesis operation steps of compound M6 described above, and the yield is 83%. Mass spectrum m / z [H + ]=1226. Elemental analysis test value: C, 57.78; H, 2.76; F, 37.18; N, 2.29.

[0084] (10) Synthesis of compound M10:

[0085] The synthesis of intermediate 10-3 was performed according to the procedure described above for intermediate 6-3, in 74% yield. Mass spectrum m / z [H + ]= 517.

[0086] The synthesis of compound M10 was performed according to the procedure described above for compound M6, in 86% yield. Mass spectrum m / z [H + ]= 1226. Elemental analysis found C, 57.76; H, 2.73; F, 37.16; N, 2.33.

[0087] (11) Synthesis of compound M11:

[0088] The synthesis of intermediate 11-3 was performed according to the procedure described above for intermediate 6-3, in 79% yield. Mass spectrum m / z [H + ]= 517.

[0089] The synthesis of compound M11 was performed according to the procedure described above for compound M6, in 83% yield. Mass spectrum m / z [H + ]= 1362. Elemental analysis found C, 53.75; H, 2.39; F, 41.85; N, 2.03.

[0090] (12) Synthesis of compound M12:

[0091] Synthesis of intermediate 12-3: Compound 12-1 (10 mmol), compound 12-2 (10 mmol), Pd(PPh3)4(0.2 mmol) and potassium carbonate (30 mmol) were dissolved in a mixed solvent of dioxane and water, stirred at 100°C under nitrogen atmosphere for 12 h. After the reaction system was cooled to room temperature, a portion of the solvent was removed by a rotary evaporator, then extracted with dichloromethane and water for 3 times. After separation, dried over MgSO4and filtered, the solvent was removed under reduced pressure; the crude product was purified by column chromatography to obtain intermediate 12-3 in 80% yield, mass spectrum m / z [H + ]= 310.

[0092] The synthesis of intermediate 12-5 was performed according to the procedure described above for intermediate 6-3, in 79% yield. Mass spectrum m / z [H + ]= 503.

[0093] The synthesis of compound M12 was performed according to the procedure described above for compound M6, in 86% yield. Mass spectrum m / z [H += 1198. Elemental analysis found C, 57.13; H, 2.54; F, 38.05; N, 2.31.

[0094] (13) Synthesis of compound M13:

[0095] The synthesis of intermediate 13-1 was according to the procedure described above for intermediate 12-3.

[0096] The synthesis of intermediate 13-3 was according to the procedure described above for intermediate 6-3, yield: 83%. Mass spectrum m / z [H + ]= 421.

[0097] The synthesis of compound M13 was according to the procedure described above for compound M6, yield: 86%. Mass spectrum m / z [H + ]= 1034. Elemental analysis found C, 61.54; H, 2.75; F, 33.01; N, 2.68.

[0098] (14) Synthesis of compound M14:

[0099] The synthesis of compound M14 was according to the procedure described above for compound M1, yield: 84%. Mass spectrum m / z [H + ]= 642. Elemental analysis found C, 87.85; H, 7.81; N, 4.38.

[0100] (15) Synthesis of compound M15:

[0101] The synthesis of compound M15 was according to the procedure described above for compound M1, yield: 84%. Mass spectrum m / z [H + ]= 699. Elemental analysis found C, 87.65; H, 8.37; N, 4.03.

[0102] (16) Synthesis of compound M16:

[0103] The synthesis of intermediate 16-3 was according to the procedure described above for intermediate 12-3, yield: 75%. Mass spectrum m / z [H + ]= 298.

[0104] The synthesis of intermediate 16-5 was according to the procedure described above for intermediate 12-5, yield: 74%. Mass spectrum m / z [H + ]= 491.

[0105] The synthesis of compound M16 was performed according to the procedure described above for compound M6. Yield: 83%. Mass spectrum m / z [H + ]=1175. Elemental analysis found C, 64.43; H, 4.14; F, 29.12; N, 2.36.

[0106] 2. Preparation of an organic light emitting device Example 1 (1) Structure of organic light emitting device 1: The organic light emitting device 1 comprises a driving substrate, a first electrode (anode) (Ag (100 nm)), a hole injection layer (HT: PD = 97:3 (mass ratio), thickness 10 nm), a hole transport layer (HT, thickness 117 nm), an electron blocking layer (EB, thickness 10 nm), a light emitting layer (BH: BD = 97:3 (mass ratio), thickness 20 nm), a hole blocking layer (HB, thickness 8 nm), an electron transport layer (ET: Liq = 1:1 (mass ratio), thickness 30 nm), an electron injection layer (LiF, thickness 1 nm), a second electrode (cathode) layer (Mg: Ag = 1:9 (mass ratio), thickness 16 nm), a first sub-cover layer (compound M1, thickness 15 nm), a second sub-cover layer (CPL-1, thickness 50 nm) which are sequentially stacked.

[0107] (2) Method for manufacturing organic light emitting device 1: First, a driving substrate layer is provided, a first electrode (anode) is formed on the driving substrate, and the first electrode is washed, i.e. sequentially washed with alkali, pure water, dried, and then washed with ultraviolet-ozone to remove organic residues on the surface of the anode layer, wherein the driving substrate layer is made of transparent glass material, and the material of the first electrode is Ag with a thickness of 100 nm; Second, a vacuum evaporation device is used to evaporate HT and PD materials on the first electrode to form a hole injection layer with a film thickness of 10 nm, and the mass ratio of HT and PD is 97:3; then HT material is evaporated on the hole injection layer to form a hole transport layer with a film thickness of 117 nm; EB material is then evaporated on the hole transport layer to form an electron blocking layer with a film thickness of 10 nm; BH and BD materials are then evaporated on the electron blocking layer to form a light emitting layer, wherein BH is used as the host material and BD is used as the dopant material, and the doping ratio of the dopant material is 3% by weight, and the film thickness of the light emitting layer is 20 nm; HB material is then evaporated on the light emitting layer to form a hole blocking layer with a film thickness of 8 nm; ET and Liq materials are then evaporated on the hole blocking layer to form an electron transport layer with a film thickness of 30 nm, and the mass ratio of ET and Liq is 1:1; finally, LiF material is evaporated on the electron transport layer to form an electron injection layer with a film thickness of 1 nm; Then, Mg and Ag materials are evaporated on the electron injection layer to form a second electrode (cathode), with a film thickness of 16 nm, wherein the mass ratio of Mg and Ag is 1:9; Finally, compound Ml is evaporated on the second electrode to form a first sub-covering layer, with a film thickness of 15 nm; then CPL-1 is evaporated on the first sub-covering layer to form a second sub-covering layer, with a film thickness of 50 nm.

[0108] Example 2 The structure and manufacturing method of the organic light-emitting device 2 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 2 is compound M2, and the other structures and materials of the organic light-emitting device 2 are the same as those of the organic light-emitting device 1.

[0109] Example 3 The structure and manufacturing method of the organic light-emitting device 3 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 3 is compound M3, and the other structures and materials of the organic light-emitting device 3 are the same as those of the organic light-emitting device 1.

[0110] Example 4 The structure and manufacturing method of the organic light-emitting device 4 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 4 is compound M4, and the other structures and materials of the organic light-emitting device 4 are the same as those of the organic light-emitting device 1.

[0111] Example 5 The structure and manufacturing method of the organic light-emitting device 5 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 5 is compound M5, and the other structures and materials of the organic light-emitting device 5 are the same as those of the organic light-emitting device 1.

[0112] Example 6 The structure and manufacturing method of the organic light-emitting device 6 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 6 is compound M6, and the other structures and materials of the organic light-emitting device 6 are the same as those of the organic light-emitting device 1.

[0113] Example 7 The structure and manufacturing method of the organic light-emitting device 7 refer to those of the organic light-emitting device 1 in Example 1, with the only difference being that the material of the first sub-covering layer of the organic light-emitting device 7 is compound M7, and the other structures and materials of the organic light-emitting device 7 are the same as those of the organic light-emitting device 1.

[0114] Example 8 The structure and fabrication method of the organic light-emitting device 8 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 8 is compound M8, and other structures and materials of the organic light-emitting device 8 are the same as those of the organic light-emitting device 1.

[0115] Embodiment 9 The structure and fabrication method of the organic light-emitting device 9 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 9 is compound M9, and other structures and materials of the organic light-emitting device 9 are the same as those of the organic light-emitting device 1.

[0116] Embodiment 10 The structure and fabrication method of the organic light-emitting device 10 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 10 is compound M10, and other structures and materials of the organic light-emitting device 10 are the same as those of the organic light-emitting device 1.

[0117] Embodiment 11 The structure and fabrication method of the organic light-emitting device 11 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 11 is compound M11, and other structures and materials of the organic light-emitting device 11 are the same as those of the organic light-emitting device 1.

[0118] Embodiment 12 The structure and fabrication method of the organic light-emitting device 12 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 12 is compound M12, and other structures and materials of the organic light-emitting device 12 are the same as those of the organic light-emitting device 1.

[0119] Embodiment 13 The structure and fabrication method of the organic light-emitting device 13 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 13 is compound M13, and other structures and materials of the organic light-emitting device 13 are the same as those of the organic light-emitting device 1.

[0120] Embodiment 14 The structure and fabrication method of the organic light-emitting device 14 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-covering layer of the organic light-emitting device 14 is compound M14, and other structures and materials of the organic light-emitting device 14 are the same as those of the organic light-emitting device 1.

[0121] Embodiment 15 The structure and fabrication method of the organic light-emitting device 15 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-cover layer of the organic light-emitting device 15 is compound M15, and other structures and materials of the organic light-emitting device 15 are the same as those of the organic light-emitting device 1.

[0122] Embodiment 16 The structure and fabrication method of the organic light-emitting device 16 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-cover layer of the organic light-emitting device 16 is compound M16, and other structures and materials of the organic light-emitting device 16 are the same as those of the organic light-emitting device 1.

[0123] Comparative Example 1 The structure and fabrication method of the organic light-emitting device 17 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the organic light-emitting device 17 only includes the first sub-cover layer without the second sub-cover layer, and the material of the first sub-cover layer is compound M1, and other structures and materials of the organic light-emitting device 17 are the same as those of the organic light-emitting device 1.

[0124] Comparative Example 2 The structure and fabrication method of the organic light-emitting device 18 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the organic light-emitting device 18 only includes the first sub-cover layer without the second sub-cover layer, and the material of the first sub-cover layer is compound M4, and other structures and materials of the organic light-emitting device 18 are the same as those of the organic light-emitting device 1.

[0125] Comparative Example 3 The structure and fabrication method of the organic light-emitting device 19 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the organic light-emitting device 19 only includes the second sub-cover layer without the first sub-cover layer, and the material of the second sub-cover layer is compound CPL-1, and other structures and materials of the organic light-emitting device 19 are the same as those of the organic light-emitting device 1.

[0126] Comparative Example 4 The structure and fabrication method of the organic light-emitting device 20 refer to those of the organic light-emitting device 1 in Embodiment 1, except that the material of the first sub-cover layer of the organic light-emitting device 20 is compound Ref-01, and other structures and materials of the organic light-emitting device 20 are the same as those of the organic light-emitting device 1.

[0127] Explanation of materials, equipment and test methods used in the embodiments of the present application: Material source: some raw materials were purchased commercially or synthesized according to prior art documents. The molecular structures of the related materials involved in the examples of the present application are shown below:

[0128]

[0129] .

[0130] Test equipment: vacuum evaporation device, 200*200mm evaporation device from Japan Changzhou Industry.

[0131] Test method: IVL (current-voltage-luminance) test system (Suzhou Fushida Scientific Instrument Co., Ltd.) was used, software EILV20060707 was selected, and the efficiency and current density relationship curves of the organic light-emitting devices 1 to 20 were tested. The data under the condition of 10 mA / cm 2 2 were taken as the reference (i.e. the performance values corresponding to the test current density of 10 mA / cm 2 2). The test results of the above organic light-emitting devices are shown in Table 1. Table 1

[0132] wherein n1 represents the refractive index of the first sub-covering layer to light with a wavelength of 460 nm, and n2 represents the refractive index of the second sub-covering layer to light with a wavelength of 460 nm.

[0133] As can be seen from the data of Examples 1-16 and Comparative Examples 1-3 in Table 1, the luminous efficiency of the organic light-emitting devices 1-16 of the present application is significantly higher than that of the organic light-emitting devices 17-19 of the comparative examples, indicating that when only a single high-refractive or low-refractive covering layer is used, the luminous efficiency of the organic light-emitting device is poor, and when the low-refractive covering layer and the high-refractive covering layer of the present application are combined, the luminous efficiency of the organic light-emitting device is significantly improved.

[0134] As can be seen from the data of Examples 1-16 and Comparative Example 4, the luminous efficiency of the organic light-emitting devices 1-16 of the present application is higher than that of the organic light-emitting device 20, i.e. when the material of the second sub-covering layer with high refractive index is maintained unchanged, the use of the organic compound of formula (1) of the present application to prepare the first sub-covering layer with low refractive index can significantly improve the luminous efficiency of the organic light-emitting device.

[0135] In summary, the organic compound represented by formula (1) of the present application can be used to prepare a cover layer with a lower refractive index, and when the low-refractive cover layer is used in combination with a high-refractive cover layer to form a cover layer structure of an organic light-emitting device, the light-emitting efficiency of the organic light-emitting device can be effectively enhanced.

[0136] In the description of the present application, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0137] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0138] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0139] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application without departing from the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. An organic compound, characterized in that, The organic compound has the structure represented by general formula (1): (1) in, Each time R appears, it is independently selected from at least one of hydrogen, fluorine, substituted or unsubstituted alkyl, or substituted or unsubstituted aromatic groups.

2. The organic compound according to claim 1, characterized in that, When R is selected from a substituted alkyl or a substituted aromatic group, the substituent is selected from an alkyl or a fluorinated group.

3. The organic compound according to claim 1, characterized in that, R is selected from at least one of hydrogen, fluorine, methyl, trifluoromethyl, fluorine-substituted phenyl, methyl-substituted phenyl, and trifluoromethyl-substituted phenyl.

4. The organic compound according to claim 1, characterized in that, The organic compound is selected from any of the following structures: 。 5. The organic compound according to any one of claims 1 to 4, characterized in that, The refractive index of the organic compound for light with a wavelength of 460 nm ranges from 1.40 to 1.

70.

6. An organic light-emitting device, characterized in that, include: First electrode; A light-emitting functional layer is disposed on the first electrode; The second electrode is disposed on the side of the light-emitting functional layer away from the first electrode; as well as A cover layer is disposed on the side of the second electrode away from the light-emitting functional layer; The material of the covering layer includes at least one organic compound as described in any one of claims 1 to 5.

7. The organic light-emitting device according to claim 6, characterized in that, The cover layer includes a first sub-cover layer and a second sub-cover layer, wherein the first sub-cover layer is located between the second electrode and the second sub-cover layer; The material of the first sub-coating layer includes at least one of the organic compounds, and the refractive index of the first sub-coating layer is less than the refractive index of the second sub-coating layer.

8. The organic light-emitting device according to claim 7, characterized in that, The first sub-coating layer has a refractive index of less than or equal to 1.60 for light with a wavelength of 460 nm, and the second sub-coating layer has a refractive index of greater than or equal to 1.85 for light with a wavelength of 460 nm.

9. The organic light-emitting device according to claim 7, characterized in that, The difference between the refractive index of the second sub-coating layer and the refractive index of the first sub-coating layer for light with a wavelength of 460 nm is greater than or equal to 0.

3. And / or, the difference between the refractive index of the first sub-coating layer for light with a wavelength of 460 nm and the refractive index of the first sub-coating layer for light with a wavelength of 620 nm is less than or equal to 0.

3.

10. A display device, characterized in that, Including the organic light-emitting device as described in any one of claims 6 to 9.

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