Organic light-emitting device and display panel

Abstract

The present application relates to an organic light-emitting device and a display panel. The organic light-emitting device includes a first electrode, a second electrode, and a light-emitting layer located between the first and second electrodes. The light-emitting layer comprises a first organic compound, a second organic compound, and a third organic compound. The second organic compound is a boron-free fluorescent material, the third organic compound contains boron, and the half-maximum width of the photoluminescence spectrum of the third organic compound is smaller than the half-maximum width of the photoluminescence spectrum of the second organic compound. The singlet lowest excitation energy levels of the second and third organic compounds are both smaller than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is shorter than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound. This application can improve the luminous efficiency of the organic light-emitting device while also extending its service life.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to an organic light-emitting device and a display panel. Background Art

[0002] Organic Light-Emitting Diodes (OLEDs) offer advantages such as thinness, energy efficiency, transparent displays, and flexible displays, and have already achieved commercial mass production in smartphones and televisions. OLEDs are electroluminescent devices composed of multiple layers of organic materials and are categorized by color. They emit red, green, and blue light, emitting the three primary colors of red, green, and blue, thanks to the use of different emitting layer materials. Red and green OLEDs utilize phosphorescent materials that can simultaneously utilize both singlet and triplet excitons to achieve an internal quantum efficiency of 100%. However, due to the short wavelength and high energy of blue OLEDs, they can only utilize fluorescent materials that emit singlet excitons. This results in an exciton utilization rate of only 25%, far lower than that of the other two color OLEDs. Subsequently, materials with triplet-triplet annihilation (TTA) were developed that can convert two triplet excitons into singlet excitons, thereby increasing the internal quantum efficiency of blue OLEDs to 75%.

[0003] As users' demands for display quality continue to rise, the luminous efficiency and service life of OLED devices need to be further improved. The display industry typically uses top-emitting organic light-emitting devices, leveraging the microcavity effect to enhance front-facing light and optimize color purity. The narrower the half-width of the luminescent material, the greater the improvement in device efficiency due to the microcavity effect. Consequently, a series of narrow-spectrum luminescent materials have been developed, such as boron nitride (BN) multi-resonance molecules, which can achieve half-widths below 20nm.

[0004] However, the stability of the CB bond in the BN-based organic light-emitting molecular structure is far lower than the CC and CN bonds in pure organic molecules, resulting in lower thermal and device stability than similar non-BN molecules, which in turn reduces the service life of blue OLED devices and limits their development. Therefore, the lifespan of blue OLED devices needs to be improved urgently. Summary of the Invention

[0005] The embodiments of the present application provide an organic light-emitting device and a display panel, which can improve the luminous efficiency of the organic light-emitting device while increasing its service life.

[0006] In order to achieve the above-mentioned object, according to a first aspect of the present application, an organic light-emitting device is provided, comprising:

[0007] a first electrode;

[0008] a second electrode, disposed opposite to the first electrode;

[0009] a light-emitting layer located between the first electrode and the second electrode; the light-emitting layer includes a first light-emitting material, a second light-emitting material, and a third light-emitting material, wherein the first light-emitting material includes a first organic compound, the second light-emitting material includes a second organic compound, and the third light-emitting material includes a third organic compound;

[0010] The second organic compound is a fluorescent material that does not contain boron, the third organic compound contains boron, and the half-peak width of the photoluminescence spectrum of the third organic compound is smaller than the half-peak width of the photoluminescence spectrum of the second organic compound; the singlet lowest excitation energy levels of the second organic compound and the third organic compound are both smaller than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound.

[0011] In some embodiments, in the material of the light-emitting layer, the mass fraction of the second organic compound is greater than the mass fraction of the third organic compound;

[0012] The mass fraction of the first organic compound is greater than or equal to 50% and less than 100%, the mass fraction of the second organic compound is greater than or equal to 1% and less than or equal to 50%, and the mass fraction of the third organic compound is greater than 0 and less than or equal to 10%.

[0013] In some embodiments, the triplet lowest excitation energy level of the first organic compound is less than 2.0 eV, and the singlet lowest excitation energy level of the first organic compound is greater than 2.4 eV.

[0014] In some embodiments, the general structural formula of the first organic compound is as shown in Formula (I):

[0015]

[0016] wherein Ar1 and Ar2 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar1 and Ar2 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0017] R1 and R2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0018] n1 and n2 are selected from any integer between 0 and 4.

[0019] In some embodiments, the first organic compound is selected from at least one of the organic compounds represented by formula (I-1) to formula (I-35):

[0020]

[0021]

[0022] In some embodiments, the second organic compound has a general structural formula as shown in Formula (II):

[0023]

[0024] Wherein, L1 and L2 are selected from a single bond, N, O, P, S, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and the substituents in L1 and L2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, and a cycloalkyl group having 3 to 30 carbon atoms;

[0025] Ar3 and Ar4 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar3 and Ar4 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0026] R3 is selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0027] n3 and n4 are selected from any integer between 0 and 2;

[0028] n5 is any integer selected from 0 to 8.

[0029] In some embodiments, the second organic compound is selected from at least one of the organic compounds represented by formula (II-1) to formula (II-39):

[0030]

[0031]

[0032] In some embodiments, the third organic compound has a general structural formula as shown in Formula (III):

[0033]

[0034] wherein Q1, Q2, and Q3 are selected from a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and a cyclic group formed by condensing a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms with a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0035] X1 and X2 are selected from O, S, N, Se or Te;

[0036] Ar5 and Ar6 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar5 and Ar6 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0037] n6 and n7 are selected from 0 or 1.

[0038] In some embodiments, at least one of X1 and X2 is selected from N, and the third organic compound is selected from at least one of the organic compounds represented by formula (III-1) to formula (III-26):

[0039]

[0040]

[0041]

[0042] According to a second aspect of the present application, a display panel is provided, comprising the organic light-emitting device described above.

[0043] In the organic light-emitting device and display panel of the embodiments of the present application, the materials of the light-emitting layer of the organic light-emitting device are composed of a first light-emitting material, a second light-emitting material, and a third light-emitting material. The first light-emitting material includes a first organic compound, the second light-emitting material includes a second organic compound, and the third light-emitting material includes a third organic compound. The second organic compound is a fluorescent material that does not contain boron. Because the singlet lowest excitation energy levels of the second and third organic compounds are both lower than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound, electrons and holes recombine in the first organic compound to form high-energy excitons. The high-energy excitons are then transferred to the second and third organic compounds through energy transfer, and the energy in the second organic compound can be further transferred to the third organic compound to emit light. On the one hand, the second organic compound does not contain boron, while the third organic compound does. Since organic compounds containing boron have poor structural stability, the second organic compound has stronger structural stability than the third organic compound, resulting in higher chemical stability and device stability of the second organic compound than the second organic compound. On the other hand, because the half-width at half-maximum of the photoluminescence spectrum of the third organic compound is smaller than that of the second organic compound, the third organic compound, as a luminescent material, is beneficial for improving the luminous efficiency and color purity of the organic light-emitting device. Therefore, during the energy transfer process, some high-energy excitons are confined to the second organic compound, which has a more stable structure. This can protect the third organic compound and thus improve the service life of the organic light-emitting device. Furthermore, when the excitons are transferred to the third organic compound, a photoluminescence spectrum with a narrow half-width at half-maximum is obtained, thereby improving the luminous efficiency and color purity of the organic light-emitting device. When the organic light-emitting device provided in this application is a blue light-emitting device, it can improve the service life of the blue light-emitting device while maintaining high luminous efficiency and high color purity.

[0044] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0046] Figure 1 This is a schematic structural diagram of an organic light-emitting device provided in an embodiment of the present application;

[0047] Figure 2 This is a schematic diagram of energy transmission in the light-emitting layer of the organic light-emitting device provided in an embodiment of the present application.

[0048] Figure numerals: 100, organic light-emitting device; 101, first electrode; 102, second electrode; 103, light-emitting layer; 104, hole injection layer; 105, hole transport layer; 106, electron blocking layer; 107, hole blocking layer; 108, electron transport layer; 109, electron injection layer; 110, light extraction layer. DETAILED DESCRIPTION

[0049] This application provides an organic light-emitting device and a display panel. To make the objectives, technical solutions, and effects of this application more clear and explicit, this application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only intended to explain this application and are not intended to limit this application. Furthermore, the order in which the following embodiments are described does not limit the preferred order of the embodiments.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this general inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless clearly defined as such herein.

[0051] In the present application, "substituted" means that a hydrogen atom in a substituted group is replaced by a substituent.

[0052] In this application, when the same substituent appears multiple times, it can be independently selected from the same or different groups. If the general formula contains multiple R, then R can be independently selected from different or the same groups.

[0053] In the present application, "substituted or unsubstituted" means that the defined group may be substituted or unsubstituted. When the defined group is substituted, it should be understood that the defined group may be substituted by one or more substituents R.

[0054] In the present application, "aromatic group" refers to an aromatic hydrocarbon group in which all the ring atoms derived from an aromatic ring compound by removing a hydrogen atom are carbon atoms. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system.

[0055] In this application, a "heteroaromatic group" refers to an aromatic group in which at least one carbon atom in the ring skeleton is replaced by a non-carbon atom, which may be an O atom, a S atom, a N atom, a P atom, a Si atom, etc. That is, the ring atoms of the heteroaromatic group include one or more non-carbon atoms selected from O atoms, S atoms, N atoms, P atoms, and Si atoms.

[0056] In this application, "alkyl" may refer to a fully saturated straight-chain, branched, and / or cyclic aliphatic hydrocarbon group. "Cycloalkyl" or "cyclic alkyl" refers to a monovalent group having one or more saturated rings in which all ring members are carbon.

[0057] Currently, to achieve higher efficiency in blue-light OLED devices, narrow-spectrum BN-based guest materials can be doped into host materials with a TTA mechanism. However, the poor molecular stability of BN-based guest materials reduces the lifespan of organic light-emitting devices.

[0058] To address the aforementioned technical issues, the present invention introduces structurally stable non-BN organic light-emitting molecules into a blue light host-guest doping system. This confines high-energy excitons within these molecules, protecting the BN guest material. Simultaneously, the non-BN organic light-emitting molecules transfer energy to the BN guest material, resulting in a photoluminescence spectrum with a narrow half-width (FWHM). This ensures high luminous efficiency and color purity while also extending the service life of the organic light-emitting device. For details, please refer to the following embodiments.

[0059] like Figure 1 As shown, an embodiment of the present application provides an organic light-emitting device 100, which includes:

[0060] a first electrode 101;

[0061] The second electrode 102 is arranged opposite to the first electrode 101;

[0062] The light-emitting layer 103 is located between the first electrode 101 and the second electrode 102. The light-emitting layer 103 includes a first light-emitting material, a second light-emitting material, and a third light-emitting material. The first light-emitting material includes a first organic compound, the second light-emitting material includes a second organic compound, and the third light-emitting material includes a third organic compound.

[0063] The second organic compound is a fluorescent material that does not contain the boron (B) element, the third organic compound contains the boron element, and the half-peak width of the photoluminescence spectrum of the third organic compound is smaller than the half-peak width of the photoluminescence spectrum of the second organic compound; the singlet lowest excitation energy levels of the second organic compound and the third organic compound are both smaller than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound.

[0064] It should be noted that, since the lowest excitation energy levels of the singlet state (i.e., singlet state) of the second organic compound and the third organic compound are both lower than the lowest excitation energy level of the singlet state of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound, the lowest excitation energy levels of the singlet state of the first organic compound, the second organic compound, and the third organic compound decrease in sequence, so that energy can be transferred from the first organic compound to the second organic compound and the third organic compound, and energy can also be transferred from the second organic compound to the third organic compound, thereby achieving luminescence.

[0065] Specifically, the luminescence principle of an organic light-emitting device is as follows: electrons and holes recombine in a first organic compound to form high-energy excitons, which are then transferred to a second organic compound and a third organic compound through energy transfer. The excitons in the second organic compound can then be further transferred to the third organic compound, thereby achieving luminescence.

[0066] like Figure 2 As shown, the singlet lowest excitation energy levels (S1) of the first organic compound, the second organic compound, and the third organic compound decrease in sequence, so that the singlet excitons can be transferred from the first organic compound to the second organic compound and the third organic compound, and the singlet excitons in the second organic compound can be further transferred to the third organic compound, and finally the excitons return to the ground state from the third organic compound, thereby realizing fluorescence luminescence.

[0067] On the one hand, because the second organic compound does not contain boron, while the third organic compound does, the second organic compound does not contain the less stable boron-carbon (BC) bond, while the third organic compound does contain the less stable BC bond. This means that the second organic compound has a higher structural stability than the third organic compound. During energy transfer, some high-energy excitons are confined to the more structurally stable second organic compound, protecting the third organic compound and thereby increasing the service life of the organic light-emitting device 100. Therefore, the second organic compound protects the third organic compound, thereby increasing the service life of the organic light-emitting device 100.

[0068] On the other hand, since the half-width at half maximum of the photoluminescence spectrum of the third organic compound is smaller than the half-width at half-maximum of the photoluminescence spectrum of the second organic compound, when excitons are transferred from the first organic compound and the second organic compound to the third organic compound, a photoluminescence spectrum with a narrower half-width at half-maximum can be obtained, which is beneficial to improving the luminous efficiency and color purity of the organic light-emitting device 100.

[0069] Therefore, the organic light-emitting device 100 provided in the embodiment of the present application has advantages such as high luminous efficiency, high color purity and long service life.

[0070] In some embodiments, the first luminescent material is a luminescent host material, the second luminescent material is a non-BN fluorescent material, and the third luminescent material is a BN guest material. Adding a structurally stable non-BN second luminescent material to the luminescent layer 103 can protect the BN guest material.

[0071] In one embodiment, the organic light emitting device 100 is a blue light emitting device, the first light emitting material is a blue light host material, and the third light emitting material is a blue light guest material. This embodiment of the application can improve the service life of the blue light emitting device while ensuring high luminous efficiency and high color purity.

[0072] In some embodiments, the first electrode 101 is an anode and the second electrode 102 is a cathode.

[0073] In some embodiments, the organic light-emitting device 100 further includes a hole injection layer 104, a hole transport layer 105, and an electron blocking layer 106 sequentially arranged between the first electrode 101 and the light-emitting layer 103, and a hole blocking layer 107, an electron transport layer 108, and an electron injection layer 109 sequentially arranged between the light-emitting layer 103 and the second electrode 102.

[0074] In some embodiments, the organic light-emitting device 100 further includes a light extraction layer 110 located on a side of the second electrode 102 facing away from the first electrode 101 , for improving light extraction efficiency.

[0075] In some embodiments, the light-emitting layer 103 is an organic layer formed by co-evaporation or pre-mixing of the first organic compound, the second organic compound, and the third organic compound and then evaporation.

[0076] In some embodiments, in the material of the light-emitting layer 103, the mass fraction of the first organic compound is greater than the mass fraction of the second organic compound, and the mass fraction of the second organic compound is greater than the mass fraction of the third organic compound. Because the mass fraction of the second organic compound is greater than the mass fraction of the third organic compound, during the energy transfer process, most high-energy excitons are concentrated in the second organic compound, thereby more effectively protecting the third organic compound and thereby increasing the service life of the organic light-emitting device.

[0077] In some embodiments, in the material of the light-emitting layer 103, the mass fraction of the first organic compound is greater than or equal to 50% and less than 100%, the mass fraction of the second organic compound is greater than or equal to 1% and less than or equal to 50%, and the mass fraction of the third organic compound is greater than 0 and less than or equal to 10%.

[0078] In a specific embodiment, the mass fraction of the first organic compound is 96%, the mass fraction of the second organic compound is 3%, and the mass fraction of the third organic compound is 1%; alternatively, the mass fraction of the first organic compound is 96.5%, the mass fraction of the second organic compound is 3%, and the mass fraction of the third organic compound is 0.5%; alternatively, the mass fraction of the first organic compound is 97%, the mass fraction of the second organic compound is 2%, and the mass fraction of the third organic compound is 1%; alternatively, the mass fraction of the first organic compound is 97.5%, the mass fraction of the second organic compound is 2%, and the mass fraction of the third organic compound is 0.5%; alternatively, the mass fraction of the first organic compound is 95%, the mass fraction of the second organic compound is 4.5%, and the mass fraction of the third organic compound is 0.5%.

[0079] In some embodiments, the triplet state lowest excitation energy level (T1) of the first organic compound is less than 2.0 eV, and the singlet state lowest excitation energy level (S1) of the first organic compound is greater than 2.4 eV.

[0080] It can be understood that in the light-emitting layer 103 of the organic light-emitting device 100 provided in the embodiment of the present application, the first light-emitting material is a triplet-triplet annihilation (TTA) material. Figure 2 As shown, triplet excitons of the first organic compound can be converted into singlet excitons, thereby improving the internal quantum efficiency of the organic light-emitting device.

[0081] In some embodiments, the first organic compound has a general structural formula as shown in Formula (I):

[0082]

[0083] wherein Ar1 and Ar2 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar1 and Ar2 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0084] R1 and R2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0085] n1 and n2 are selected from any integer between 0 and 4.

[0086] In some embodiments, the heteroatom in the heteroaromatic group in the embodiments of the present application is selected from at least one of O, S, N, P, and Si.

[0087] In one embodiment, the first organic compound is selected from at least one of the organic compounds represented by formula (I-1) to formula (I-35):

[0088]

[0089]

[0090] It can be understood that the first light-emitting material includes at least one of the first organic compounds listed above.

[0091] In some embodiments, the second organic compound has a general structural formula as shown in Formula (II):

[0092]

[0093] Wherein, L1 and L2 are selected from a single bond, N, O, P, S, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and the substituents in L1 and L2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, and a cycloalkyl group having 3 to 30 carbon atoms;

[0094] Ar3 and Ar4 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar3 and Ar4 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0095] R3 is selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0096] n3 and n4 are selected from any integer between 0 and 2;

[0097] n5 is any integer selected from 0 to 8.

[0098] In one embodiment, the second organic compound is selected from at least one of the organic compounds represented by formula (II-1) to formula (II-39):

[0099]

[0100]

[0101]

[0102] It can be understood that the second light-emitting material includes at least one of the second organic compounds listed above.

[0103] It should be noted that the second organic compound provided in the embodiment of the present application is a fluorescent material, which has high stability and can improve the service life of the light-emitting device. In addition, compared with thermally activated delayed fluorescence (TADF) materials, the molecular stability of the second organic compound provided in the embodiment of the present application is better and can be used for blue light devices. Although TADF material can improve the exciton utilization rate, the material is a DA configuration, and its molecular stability is relatively poor, and it is generally used for green or red light devices. Therefore, the present application can effectively improve the service life of blue light devices by adding a second organic compound to the blue light emitting layer containing the aforementioned first organic compound and the third organic compound.

[0104] In some embodiments, the third organic compound has a general structural formula as shown in Formula (III):

[0105]

[0106] wherein Q1, Q2, and Q3 are selected from a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and a cyclic group formed by condensing a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms with a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms;

[0107] X1 and X2 are selected from O, S, N, Se or Te;

[0108] Ar5 and Ar6 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar1 and Ar2 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms;

[0109] n6 and n7 are selected from 0 or 1.

[0110] In some embodiments, at least one of X1 and X2 is selected from N, that is, the third light-emitting material containing the third organic compound is a BN-based guest material and has a narrow half-width, which is beneficial to improving the luminous efficiency and color purity of the organic light-emitting device.

[0111] In one embodiment, the third organic compound is selected from at least one of the organic compounds represented by formula (III-1) to formula (III-26):

[0112]

[0113]

[0114] It can be understood that the third light-emitting material includes at least one of the third organic compounds listed above.

[0115] In an embodiment of the present application, the materials of the light-emitting layer of the organic light-emitting device are composed of a first light-emitting material, a second light-emitting material, and a third light-emitting material. The first light-emitting material includes a first organic compound, the second light-emitting material includes a second organic compound, and the third light-emitting material includes a third organic compound. The second organic compound is a fluorescent material that does not contain boron. Because the singlet lowest excitation energy levels of the second organic compound and the third organic compound are both lower than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound, electrons and holes recombine in the first organic compound to form high-energy excitons. The high-energy excitons are then transferred to the second and third organic compounds through energy transfer, and the energy in the second organic compound can be further transferred to the third organic compound, thereby generating light.

[0116] On the one hand, the second organic compound does not contain boron, while the third organic compound contains boron. Since the structural stability of organic compounds containing boron is relatively poor, the structural stability of the second organic compound is stronger than that of the third organic compound, so that the chemical stability and device stability of the second organic compound are higher than those of the second organic compound.

[0117] On the other hand, since the half-peak width of the photoluminescence spectrum of the third organic compound is smaller than that of the second organic compound, the third organic compound as a luminescent material is beneficial to improving the luminous efficiency and color purity of the organic light-emitting device.

[0118] Therefore, during the energy transfer process, some high-energy excitons are confined to the second organic compound with a more stable structure, which can protect the third organic compound and thus help to improve the service life of the organic light-emitting device; at the same time, when the excitons are transferred to the third organic compound, a photoluminescence spectrum with a narrow half-width can be obtained, thereby improving the luminous efficiency and color purity of the organic light-emitting device.

[0119] When the organic light-emitting device provided in the present application is a blue light device, the service life of the blue light device can be improved while ensuring high luminous efficiency and high color purity.

[0120] This application also provides Examples 1 to 10 to describe the method for manufacturing the above-mentioned organic light-emitting device. In addition, this application also provides Comparative Examples 1 and 2, which compare the performance of the organic light-emitting devices prepared in Examples 1 to 10 of this application with the organic light-emitting devices provided in Comparative Examples 1 and 2.

[0121] Example 1

[0122] The preparation process of the organic light-emitting device OLED-1 includes the following steps:

[0123] providing an ITO (indium tin oxide) anode as a first electrode;

[0124] When the vacuum evaporation machine reduces the vacuum degree to 4*10 -4 In the case of pa, a hole injection layer (HATCN, 10 nm), a hole transport layer (HTL, 120 nm), an electron blocking layer (EBL, 10 nm), a light-emitting layer (20 nm), a hole blocking layer (HBL, 5 nm), an electron transport layer (ETL: LiQ, 30 nm), an electron injection layer (LiQ, 1 nm), a second electrode (Ag, 12 nm) and a light extraction layer (CPL, 70 nm) are sequentially vapor-deposited on the ITO anode of the full-emission substrate.

[0125] Among them, the material of the light-emitting layer is selected from a first organic compound represented by formula (I-14), a second organic compound represented by formula (II-11) and a third organic compound represented by formula (III-2), and the mass fraction ratio of the first organic compound, the second organic compound and the third organic compound is 96%:3%:1%.

[0126] The structural formulas of the general materials used in the preparation process are shown below:

[0127]

[0128] Example 2 to Example 5

[0129] The organic light-emitting devices provided in Examples 2 to 5 are OLED-2 to OLED-5, respectively. The preparation methods of OLED-2 to OLED-5 are the same as those in Example 1, and the material component types of the light-emitting layers are the same. The difference is that the mass fraction ratios of the first organic compound, the second organic compound, and the third organic compound in the light-emitting layer are different.

[0130] In the light-emitting layer of OLED-2 provided in Example 2, the mass fraction ratio of the first organic compound represented by formula (I-14), the second organic compound represented by formula (II-11) and the third organic compound represented by formula (III-2) is 96.5%:3%:0.5%.

[0131] In the light-emitting layer of OLED-3 provided in Example 3, the mass fraction ratio of the first organic compound represented by formula (I-14), the second organic compound represented by formula (II-11) and the third organic compound represented by formula (III-2) is 97%:2%:1%.

[0132] In the light-emitting layer of OLED-4 provided in Example 4, the mass fraction ratio of the first organic compound represented by formula (I-14), the second organic compound represented by formula (II-11) and the third organic compound represented by formula (III-2) is 97.5%:2%:0.5%.

[0133] In the light-emitting layer of OLED-5 provided in Example 5, the mass fraction ratio of the first organic compound represented by formula (I-14), the second organic compound represented by formula (II-11) and the third organic compound represented by formula (III-2) is 95%:4.5%:0.5%.

[0134] Example 6 to Example 10

[0135] The organic light-emitting devices provided in Examples 6 to 10 are OLED-6 to OLED-10, respectively. The preparation methods of OLED-6 to OLED-10 are the same as those in Example 1, except that the materials of the light-emitting layers of OLED-6 to OLED-10 are selected from the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28), and the third organic compound represented by formula (III-15).

[0136] In the light-emitting layer of OLED-6 provided in Example 6, the mass fraction ratio of the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28) and the third organic compound represented by formula (III-15) is 96%:3%:1%.

[0137] In the light-emitting layer of OLED-7 provided in Example 7, the mass fraction ratio of the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28) and the third organic compound represented by formula (III-15) is 96.5%:3%:0.5%.

[0138] In the light-emitting layer of OLED-8 provided in Example 8, the mass fraction ratio of the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28) and the third organic compound represented by formula (III-15) is 97%:2%:1%.

[0139] In the light-emitting layer of OLED-9 provided in Example 9, the mass fraction ratio of the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28) and the third organic compound represented by formula (III-15) is 97.5%:2%:0.5%.

[0140] In the light-emitting layer of OLED-10 provided in Example 10, the mass fraction ratio of the first organic compound represented by formula (I-23), the second organic compound represented by formula (II-28) and the third organic compound represented by formula (III-15) is 95%:4.5%:0.5%.

[0141] Comparative Example 1

[0142] The organic light-emitting device provided in Comparative Example 1 is OLED-Ref1. The preparation method of OLED-Ref1 is the same as that of Example 1, except that the material of the light-emitting layer of OLED-Ref1 is selected from the first organic compound represented by formula (I-14) and the third organic compound represented by formula (III-2), and the mass fraction ratio of the first organic compound to the third organic compound is 95%:5%.

[0143] Comparative Example 2

[0144] The organic light-emitting device provided in Comparative Example 2 is OLED-Ref2. The preparation method of OLED-Ref2 is the same as that of Example 1, except that the material of the light-emitting layer of OLED-Ref1 is selected from the first organic compound represented by formula (I-23) and the third organic compound represented by formula (III-15), and the mass fraction ratio of the first organic compound to the third organic compound is 95%:5%.

[0145] That is, the OLED-Ref1 and OLED-Ref2 provided in Comparative Examples 1 and 2 do not contain the second organic compound provided in the examples of the present application.

[0146] The test results of voltage (V), luminous efficiency (cd / A), half-peak width (nm) and service life (hr) of OLED-1 to OLED-2 provided in Examples 1 to 10 of the present application and OLED-Ref1 and OLED-Ref2 provided in Comparative Examples 1 and 2 are shown in Table 1. The voltage (V) and luminous efficiency (cd / A) of the light-emitting device are taken from the current density of 10 mA / cm 2 Time data, service life is 20mA / cm 2 The data is obtained by the following test, and the data when the brightness is attenuated to 95% is selected.

[0147] Table 1

[0148]

[0149]

[0150] Comparing the test results of OLED-5 with OLED-Ref1, and OLED-10 with OLED-Ref2 in Table 1, we can see that when the sum of the mass fractions of the second and third organic compounds is the same, the device voltage and luminous efficiency remain essentially unchanged, while the service life is significantly improved. Comparing the test results of OLED-1 through OLED-4 with OLED-Ref1, and OLED-6 through OLED-10 with OLED-Ref2 in Table 1, we can see that when the sum of the mass fractions of the second and third organic compounds decreases, the device luminous efficiency tends to increase, and the service life is still significantly improved.

[0151] This shows that the luminous efficiency of the organic light-emitting device containing the second organic compound is at a high level, and the service life of the organic light-emitting device can be effectively improved by adding the second organic compound (second light-emitting material) to the light-emitting material containing the first organic compound (first light-emitting material) and the third organic compound (third light-emitting material).

[0152] An embodiment of the present application further provides a display panel, which includes the organic light-emitting device described in the above embodiment.

[0153] In some embodiments, the organic light-emitting device described in the aforementioned embodiments is a blue light-emitting device, and the display panel further includes other organic light-emitting devices, including red light-emitting devices and green light-emitting devices, but not limited thereto.

[0154] In some embodiments, the organic light emitting device can directly emit light to display a pattern. In other embodiments, the organic light emitting device can be used as a backlight to provide a light source.

[0155] In the embodiment of the present application, since the organic light-emitting device has high luminous efficiency, high color purity and long service life, the display panel using the organic light-emitting device has a high-quality display effect and a long service life.

[0156] The first organic compound, the second organic compound, and the third organic compound provided in the embodiments of the present application can be used in displays such as mobile phones, vehicles, virtual reality / augmented reality (AR / VR), notebooks, monitors, and televisions as high-efficiency, long-life luminescent materials.

[0157] The organic light-emitting devices provided in the embodiments of the present application can be used in displays such as mobile phones, vehicles, AR / VR, notebooks, monitors, and televisions as high-performance components.

[0158] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0159] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0160] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0161] The above are merely preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. An organic light-emitting device, characterized in that: include: a first electrode; a second electrode, disposed opposite to the first electrode; a light-emitting layer located between the first electrode and the second electrode; the light-emitting layer includes a first light-emitting material, a second light-emitting material, and a third light-emitting material, wherein the first light-emitting material includes a first organic compound, the second light-emitting material includes a second organic compound, and the third light-emitting material includes a third organic compound; The second organic compound is a fluorescent material that does not contain boron, the third organic compound contains boron, and the half-width of the photoluminescence spectrum of the third organic compound is smaller than the half-width of the photoluminescence spectrum of the second organic compound; the singlet lowest excitation energy levels of the second organic compound and the third organic compound are both smaller than the singlet lowest excitation energy level of the first organic compound, and the shortest emission wavelength of the photoluminescence spectrum of the third organic compound is lower than the shortest emission wavelength of the photoluminescence spectrum of the second organic compound; the triplet lowest excitation energy level of the first organic compound is less than 2.0 eV, and the singlet lowest excitation energy level of the first organic compound is greater than 2.4 eV.

2. The organic light-emitting device according to claim 1, wherein In the material of the light-emitting layer, the mass fraction of the second organic compound is greater than the mass fraction of the third organic compound; The mass fraction of the first organic compound is greater than or equal to 50% and less than 100%, the mass fraction of the second organic compound is greater than or equal to 1% and less than or equal to 50%, and the mass fraction of the third organic compound is greater than 0 and less than or equal to 10%.

3. The organic light-emitting device according to claim 1 or 2, characterized in that: The general structural formula of the first organic compound is shown in Formula (I): wherein Ar1 and Ar2 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar1 and Ar2 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms; R1 and R2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms; n1 and n2 are selected from any integer between 0 and 4.

4. The organic light-emitting device according to claim 3, characterized in that The first organic compound is at least one selected from the group consisting of organic compounds represented by formula (I-1) to formula (I-35): 。 5. The organic light-emitting device according to claim 1 or 2, characterized in that: The general structural formula of the second organic compound is shown in Formula (II): Wherein, L1 and L2 are selected from a single bond, N, O, P, S, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and the substituents in L1 and L2 are selected from deuterium, an alkyl group having 3 to 30 carbon atoms, and a cycloalkyl group having 3 to 30 carbon atoms; Ar3 and Ar4 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar3 and Ar4 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms; R3 is selected from deuterium, an alkyl group having 3 to 30 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms; n3 and n4 are selected from any integer between 0 and 2; n5 is any integer selected from 0 to 8.

6. The organic light-emitting device according to claim 5, characterized in that: The second organic compound is at least one selected from the group consisting of organic compounds represented by formula (II-1) to formula (II-39): 。 7. The organic light-emitting device according to claim 1 or 2, characterized in that: The general structural formula of the third organic compound is shown in formula (III): wherein Q1, Q2, and Q3 are selected from a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms, and a cyclic group formed by condensing a substituted or unsubstituted aromatic group having 6 to 30 carbon atoms with a substituted or unsubstituted heteroaromatic group having 5 to 30 carbon atoms; X1 and X2 are selected from O, S, N, Se or Te; Ar5 and Ar6 are selected from substituted or unsubstituted aromatic groups having 6 to 30 carbon atoms, and substituted or unsubstituted heteroaromatic groups having 5 to 30 carbon atoms, and the substituents in Ar5 and Ar6 are selected from deuterium, alkyl groups having 3 to 30 carbon atoms, cycloalkyl groups having 3 to 30 carbon atoms, aromatic groups having 6 to 30 carbon atoms, and heteroaromatic groups having 5 to 30 carbon atoms; n6 and n7 are selected from 0 or 1.

8. The organic light-emitting device according to claim 7, characterized in that: At least one of X1 and X2 is selected from N, and the third organic compound is selected from at least one of the organic compounds represented by formula (III-1) to formula (III-26): 。 9. A display panel, characterized in that: The organic light-emitting device comprises the organic light-emitting device according to any one of claims 1 to 8.

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