Woled device and display apparatus

Abstract

The present application belongs to the technical field of display. Disclosed are a WOLED device and a display apparatus. The WOLED device comprises, successively stacked, an anode, a hole transport unit, an organic light-emitting unit, an electron transport unit and a cathode. The organic light-emitting unit comprises, successively stacked, a blue light-emitting layer, an interlayer, a green light-emitting layer and a red light-emitting layer, the interlayer having an electron transport feature, and the |HOMO| of the interlayer being greater than or equal to a first set threshold value; or the organic light-emitting unit comprises, successively stacked, a red light-emitting layer, an interlayer, a blue light-emitting layer and a green light-emitting layer, the interlayer having a hole transport feature, and the |LUMO| of the interlayer being less than or equal to a second set threshold value. The WOLED device can give consideration to both the balanced light emission of its three RGB light-emitting layers and the service life of the device.

Description

WOLED device and display device

[0001] This application claims priority to Chinese patent application No. 202410190417.2, filed on February 20, 2024, entitled “WOLED device and display device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a WOLED device and a display apparatus. Background Art

[0003] White organic light emitting diodes (WOLED), also known as white organic light emitting devices, can be used not only for lighting, but also for backlight sources of liquid crystal displays and full-color OLED displays.

[0004] Depending on the device structure, white organic light-emitting devices include single-layer devices and dual-layer devices. In dual-layer devices, the two organic light-emitting layers are connected by a charge generation layer (CGL). The CGL typically consists of a P-type doped hole transport material and an N-type doped electron transport material. Its conductivity is stronger than that of other organic film layers, resulting in a correspondingly increased risk of lateral leakage. Single-layer devices, because they do not use a charge generation layer, can effectively avoid the problem of lateral leakage.

[0005] However, for current single-stack light-emitting devices, it is difficult to simultaneously take into account the balanced luminescence of the RGB light-emitting layers and the service life of the device. Summary of the Invention

[0006] In view of this, the present disclosure provides a WOLED device and a display apparatus, which can solve the technical problems existing in the related art.

[0007] Specifically, the following technical solutions are included:

[0008] In one aspect, a WOLED device is provided, comprising: an anode, a hole transport unit, an organic light emitting unit, an electron transport unit, and a cathode stacked in sequence;

[0009] The organic light-emitting unit includes: a blue light-emitting layer, a spacer, a green light-emitting layer and a red light-emitting layer stacked in sequence, the blue light-emitting layer is further stacked with the hole transport unit, and the red light-emitting layer is further stacked with the electron transport unit;

[0010] The spacer has electron transport characteristics, and |HOMO| of the spacer is greater than or equal to a first set threshold.

[0011] The WOLED device provided in the embodiments of the present disclosure utilizes an improved organic light-emitting unit, comprising a blue light-emitting layer, an interlayer, a green light-emitting layer, and a red light-emitting layer stacked in sequence. The interlayer exhibits electron transport properties, facilitating the transfer of some electrons from the cathode through the red and green light-emitting layers to the blue light-emitting layer. Furthermore, the interlayer's |HOMO| value is greater than or equal to a first predetermined threshold, meaning that the interlayer possesses a deep HOMO absolute value. This helps block some holes from being transferred from the anode through the blue light-emitting layer to the red and green light-emitting layers. This confines some electrons and holes to the blue light-emitting layer, where they undergo recombination transition emission, while the remaining electrons and holes undergo recombination transition emission in the red and green light-emitting layers, respectively. Consequently, the blue, red, and green light-emitting layers emit light in their respective wavelength bands, achieving balanced RGB color emission and enhancing the WOLED device's longevity.

[0012] In some possible implementations, the spacer satisfies the following conditions: electron mobility μ e 1×10 -6 cm 2 / Vs~1×10 -4 cm 2 / Vs, and |HOMO|≥6.01eV.

[0013] In some possible implementations, the spacer is made of at least one of the following materials:

[0014] In some possible implementations, the blue light-emitting layer includes a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%;

[0015] The green light emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%;

[0016] The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%.

[0017] In some possible implementations, the first host material is at least one of a pyrene derivative-based blue light-emitting material, anthracene derivative-based blue light-emitting material, fluorene derivative-based blue light-emitting material, and perylene derivative-based blue light-emitting material, and the blue light dopant is a blue fluorescent material;

[0018] The second host material is at least one of a coumarin dye, a quinacridone copper derivative green luminescent material, a polycyclic aromatic hydrocarbon green luminescent material, a diamine anthracene derivative green luminescent material, a carbazole derivative green luminescent material, and a metal complex green luminescent material, and the green light dopant is a green phosphorescent material;

[0019] The third host material is at least one of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran and 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulonitrile-9-enyl)-4H-pyran, and the red light dopant is a red phosphorescent material.

[0020] In another aspect, a WOLED device is provided, comprising: an anode, a hole transport unit, an organic light emitting unit, an electron transport unit, and a cathode stacked in sequence;

[0021] The organic light-emitting unit includes: a red light-emitting layer, a spacer, a blue light-emitting layer and a green light-emitting layer stacked in sequence, the red light-emitting layer is further stacked with the hole transport unit, and the green light-emitting layer is further stacked with the electron transport unit;

[0022] The spacer has hole transport characteristics, and the |LUMO| of the spacer is less than or equal to a second set threshold.

[0023] The WOLED device provided in the embodiments of the present disclosure utilizes an improved organic light-emitting unit, comprising a red light-emitting layer, an interlayer, a blue light-emitting layer, and a green light-emitting layer stacked in sequence. The interlayer's hole-transport properties facilitate the transfer of some holes from the anode through the red light-emitting layer to the blue and green light-emitting layers. Furthermore, the interlayer's |LUMO| is less than or equal to a second predetermined threshold, meaning it also possesses a shallow LUMO absolute value. This helps block some electrons from transferring from the cathode through the green and blue light-emitting layers to the red light-emitting layer. This confines some electrons and holes to the blue and green light-emitting layers for recombination and transition emission, while the remaining electrons and holes undergo recombination and transition emission in the red light-emitting layer. Consequently, the blue, red, and green light-emitting layers emit light in their respective wavelength bands, achieving balanced RGB color emission and enhancing the WOLED device's longevity.

[0024] In some possible implementations, the spacer satisfies the following conditions: hole mobility μ h 1×10 -5 cm 2 / Vs~1×10 -4 cm 2 / Vs, and |LUMO|≤2.48eV.

[0025] In some possible implementations, the spacer is made of at least one of the following materials:

[0026] In some possible implementations, the blue light-emitting layer includes a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%;

[0027] The green light emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%;

[0028] The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%.

[0029] In some possible implementations, the first host material is at least one of a pyrene derivative-based blue light-emitting material, anthracene derivative-based blue light-emitting material, fluorene derivative-based blue light-emitting material, and perylene derivative-based blue light-emitting material, and the blue light dopant is a blue fluorescent material;

[0030] The second host material is at least one of a coumarin dye, a quinacridone copper derivative green luminescent material, a polycyclic aromatic hydrocarbon green luminescent material, a diamine anthracene derivative green luminescent material, a carbazole derivative green luminescent material, and a metal complex green luminescent material, and the green light dopant is a green phosphorescent material;

[0031] The third host material is at least one of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran and 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulonitrile-9-enyl)-4H-pyran, and the red light dopant is a red phosphorescent material.

[0032] In another aspect, a display device is provided, comprising any one of the above-mentioned WOLED devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0034] FIG1 is a structural arrangement diagram of an exemplary WOLED device provided by the present disclosure;

[0035] FIG2 is a structural arrangement diagram of another exemplary WOLED device provided by the present disclosure;

[0036] FIG3 is a PL spectrum diagram of the WOLED devices provided in Example 1 and Comparative Example 1;

[0037] FIG4 is a PL spectrum diagram of the WOLED devices provided in Example 2 and Comparative Example 2. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present disclosure in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0039] The embodiments of the present disclosure explain the terms of some functional layers involved in the WOLED device as follows: hole injection layer - HIL; hole transport layer - HTL; electron blocking layer - EBL; hole blocking layer - HBL; electron transport layer - ETL; electron injection layer - EIL; highest occupied molecular orbital - HOMO; lowest unoccupied molecular orbital - LUMO.

[0040] To make the technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be described in further detail below with reference to the accompanying drawings.

[0041] Single-stack WOLED devices, because they do not use a charge-generating layer, can effectively avoid lateral leakage. However, in current single-stack WOLED devices, the blue, green, and red (RGB) light-emitting layers can be stacked in any order. This requires the three layers to both emit light and transfer charge to each other. Therefore, it is crucial to balance the light emission of the RGB layers while ensuring the lifespan of the WOLED device. However, current WOLED devices struggle to achieve both balanced light emission and device lifespan.

[0042] According to one aspect of an embodiment of the present disclosure, a WOLED device is provided, comprising: an anode, a hole transport unit, an organic light-emitting unit, an electron transport unit, and a cathode stacked in sequence. The organic light-emitting unit comprises: a blue light-emitting layer, an interlayer, a green light-emitting layer, and a red light-emitting layer stacked in sequence, the blue light-emitting layer is further stacked with the hole transport unit, and the red light-emitting layer is further stacked with the electron transport unit. That is, along the direction from the anode to the cathode, the hole transport unit, the blue light-emitting layer, the interlayer, the green light-emitting layer, the red light-emitting layer, and the electron transport unit are stacked in sequence. The interlayer has electron transport characteristics, and the |HOMO| (i.e., the absolute value of the highest occupied molecular orbital HOMO energy level) of the interlayer is greater than or equal to a first set threshold.

[0043] For example, Figure 1 illustrates the structure of a WOLED device for this implementation, which includes an anode Anode, a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, a blue light-emitting layer BEML, an interlayer IL, a green light-emitting layer GEML, a red light-emitting layer REML, a hole blocking layer HBL, an electron transport layer ETL, an electron injection layer EIL and a cathode arranged in sequence.

[0044] The WOLED device provided in the embodiments of the present disclosure utilizes an improved organic light-emitting unit, comprising a blue light-emitting layer, an interlayer, a green light-emitting layer, and a red light-emitting layer stacked in sequence. The interlayer exhibits electron transport properties, facilitating the transfer of some electrons from the cathode through the red and green light-emitting layers to the blue light-emitting layer. Furthermore, the interlayer's |HOMO| value is greater than or equal to a first predetermined threshold, meaning that the interlayer possesses a deep HOMO absolute value. This helps block some holes from being transferred from the anode through the blue light-emitting layer to the red and green light-emitting layers. This confines some electrons and holes to the blue light-emitting layer, where they undergo recombination transition emission, while the remaining electrons and holes undergo recombination transition emission in the red and green light-emitting layers, respectively. Consequently, the blue, red, and green light-emitting layers emit light in their respective wavelength bands, achieving balanced RGB color emission and enhancing the WOLED device's longevity.

[0045] In some implementations, the above-mentioned spacer has electron transport characteristics, which can make the spacer meet its electron mobility μ e 1×10 -6 cm 2 / Vs~1×10 -4 cm 2 / Vs, thus ensuring that the spacer has excellent electron transport properties.

[0046] Regarding the interlayer's |HOMO| being greater than or equal to the first set threshold, the first set threshold may be 6.01 eV, that is, the interlayer's |HOMO|≥6.01 eV, thereby ensuring that the interlayer has the characteristic of a deep HOMO absolute value.

[0047] Materials that can meet the above-mentioned electron mobility and |HOMO| characteristics are suitable for preparing the spacer involved in the WOLED device. The spacer is prepared using at least one of the following materials. The abbreviations of the following materials are noted below their chemical structures:

[0048] When forming the partition layer, any one of the above materials may be used, or a combination of at least one of the above materials may be used.

[0049] The WOLED device involved in the embodiment of the present disclosure has a blue light-emitting layer including a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%, including but not limited to 1%, 2%, 3%, 4%, 5%, etc.

[0050] The green light-emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%, which includes 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0051] The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%, including but not limited to 1%, 2%, 3%, 4%, 5% and the like.

[0052] The blue, green, and red light-emitting layers all use a system consisting of a host material and a dopant, and the doping ratios of each dopant are shown above, ensuring that the blue, green, and red light-emitting layers each have excellent efficiency and lifespan.

[0053] For the blue light-emitting layer, the first host material involved may include any one or more of pyrene derivative blue light-emitting materials, anthracene derivative blue light-emitting materials, fluorene derivative blue light-emitting materials, and perylene derivative blue light-emitting materials.

[0054] For example, the blue light-emitting material may include any one or more of: N1,N6-di([1,1'-biphenyl]-2-yl)-N1,N6-di([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), and 2,5,8,11-tetra-tert-butylperylene (TBPe).

[0055] The blue light dopant involved is a blue fluorescent material, and the peak range of the photoluminescence spectrum (PL) of the blue fluorescent material is 430nm-480nm.

[0056] For example, the blue fluorescent material includes aromatic luminescent groups, aniline luminescent groups, etc. For further example, the blue fluorescent material can be any one or more of styrylamine derivative blue luminescent materials and metal complex blue luminescent materials.

[0057] For example, the blue light-emitting material may include any one or more of 4,4′-bis[4-(diphenylamino)phenylphenyl]biphenyl (BDAVBi), 4,4′-bis[4-(di-p-tolylamino)phenylphenyl]biphenyl (DPAVBi), and bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium (FIrpic).

[0058] For the green light-emitting layer, the second main material involved may include: any one or more of coumarin dyes, quinacridone copper derivatives green light-emitting materials, polycyclic aromatic hydrocarbons green light-emitting materials, diamine anthracene derivatives green light-emitting materials, carbazole derivatives green light-emitting materials and metal complexes green light-emitting materials.

[0059] For example, the green light-emitting materials involved in the second host material may include: coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N'-dimethylquinacridone (DMQA), 5,12-diphenylnaphthonaphthalene (DPT), N10,N10'-diphenyl-N10,N10'-diphthaloyl-9,9'-dianthracene-10,10'-diamine (abbreviated as: BA-NPB), etc.

[0060] The green light dopant involved is a green phosphorescent material. Exemplarily, the peak of the PL spectrum of the green phosphorescent material is 520nm-550nm. Exemplarily, the green phosphorescent material includes a heavy metal atom center and an organic conjugated group connected to the heavy metal atom center, wherein the heavy metal atom can be an Ir atom or a Pt atom, and the organic conjugated group can be a benzene ring group.

[0061] Exemplarily, the green phosphorescent material may include any one or more of tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), and di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)).

[0062] For the red light-emitting layer, the third host material involved may include any one or more of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidine-9-enyl)-4H-pyran (DCJTB).

[0063] The red light dopant involved is a red phosphorescent material having a PL spectrum peak range of 580nm-650nm. Exemplarily, the red phosphorescent material includes a heavy metal atom center and an organic conjugated group connected to the heavy metal atom center, wherein the heavy metal atom can be an Ir atom or a Pt atom, and the organic conjugated group can be a benzene ring group.

[0064] Exemplarily, the red phosphorescent material may include any one or more of: bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as: PtOEP), and bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetonate)iridium (abbreviated as: Ir(btp)2(acac)).

[0065] According to another aspect of the embodiments of the present disclosure, a WOLED device is provided. The WOLED device includes: an anode, a hole transport unit, an organic light-emitting unit, an electron transport unit, and a cathode, which are sequentially stacked. The organic light-emitting unit includes: a red light-emitting layer, an interlayer, a blue light-emitting layer, and a green light-emitting layer, which are sequentially stacked. The red light-emitting layer is further stacked with the hole transport unit, and the green light-emitting layer is further stacked with the electron transport unit. In other words, the hole transport unit, red light-emitting layer, interlayer, blue light-emitting layer, green light-emitting layer, and electron transport unit are sequentially stacked in a direction from the anode to the cathode.

[0066] The spacer has hole transport characteristics, and |LUMO| (ie, the absolute value of the lowest unoccupied molecular orbital LUMO) of the spacer is less than or equal to a second set threshold.

[0067] For example, Figure 2 illustrates the structure of a WOLED device for this implementation, which includes an anode Anode, a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, a red light-emitting layer REML, an interlayer IL, a blue light-emitting layer BEML, a green light-emitting layer GEML, a hole blocking layer HBL, an electron transport layer ETL, an electron injection layer EIL and a cathode arranged in sequence.

[0068] The WOLED device provided in the embodiments of the present disclosure utilizes an improved organic light-emitting unit, comprising a red light-emitting layer, an interlayer, a blue light-emitting layer, and a green light-emitting layer stacked in sequence. The interlayer's hole-transport properties facilitate the transfer of some holes from the anode through the red light-emitting layer to the blue and green light-emitting layers. Furthermore, the interlayer's |LUMO| is less than or equal to a second predetermined threshold, meaning it also possesses a shallow LUMO absolute value. This helps block some electrons from transferring from the cathode through the green and blue light-emitting layers to the red light-emitting layer. This confines some electrons and holes to the blue and green light-emitting layers for recombination and transition emission, while the remaining electrons and holes undergo recombination and transition emission in the red light-emitting layer. Consequently, the blue, red, and green light-emitting layers emit light in their respective wavelength bands, achieving balanced RGB color emission and enhancing the WOLED device's longevity.

[0069] In some implementations, the aforementioned interlayer has hole transport characteristics, which can satisfy the hole mobility μ h 1×10 -5 cm 2 / Vs~1×10 -4 cm 2 / Vs, thereby ensuring that the spacer has excellent hole transport properties.

[0070] Regarding the interlayer involved above, the |LUMO| is less than or equal to the second set threshold, which may be 2.48 eV, ie, |LUMO|≤2.48 eV, thereby ensuring that the interlayer has a characteristic of a shallow LUMO absolute value.

[0071] Materials that can meet the above-mentioned hole mobility and |LUMO| characteristics are suitable for preparing the spacer involved in the WOLED device. The spacer is prepared using at least one of the following materials. The abbreviations of the following materials are noted below their chemical structures:

[0072] When forming the partition layer, any one of the above materials may be used, or a combination of at least one of the above materials may be used.

[0073] The WOLED device involved in the embodiment of the present disclosure has a blue light-emitting layer including a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%, including but not limited to 1%, 2%, 3%, 4%, 5%, etc.

[0074] The green light-emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%, which includes 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0075] The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%, including but not limited to 1%, 2%, 3%, 4%, 5% and the like.

[0076] The blue, green, and red light-emitting layers all use a system consisting of a host material and a dopant, and the doping ratios of each dopant are shown above, ensuring that the blue, green, and red light-emitting layers each have excellent efficiency and lifespan.

[0077] For the blue light-emitting layer, the first host material involved may include any one or more of pyrene derivative blue light-emitting materials, anthracene derivative blue light-emitting materials, fluorene derivative blue light-emitting materials, and perylene derivative blue light-emitting materials.

[0078] For example, the blue light-emitting material may include any one or more of: N1,N6-di([1,1'-biphenyl]-2-yl)-N1,N6-di([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), and 2,5,8,11-tetra-tert-butylperylene (TBPe).

[0079] The blue light dopant involved is a blue fluorescent material, and the peak range of the photoluminescence spectrum (PL) of the blue fluorescent material is 430nm-480nm.

[0080] For example, the blue fluorescent material includes aromatic luminescent groups, aniline luminescent groups, etc. For further example, the blue fluorescent material can be any one or more of styrylamine derivative blue luminescent materials and metal complex blue luminescent materials.

[0081] For example, the blue light-emitting material may include any one or more of 4,4′-bis[4-(diphenylamino)phenylphenyl]biphenyl (BDAVBi), 4,4′-bis[4-(di-p-tolylamino)phenylphenyl]biphenyl (DPAVBi), and bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium (FIrpic).

[0082] For the green light-emitting layer, the second main material involved may include: any one or more of coumarin dyes, quinacridone copper derivatives green light-emitting materials, polycyclic aromatic hydrocarbons green light-emitting materials, diamine anthracene derivatives green light-emitting materials, carbazole derivatives green light-emitting materials and metal complexes green light-emitting materials.

[0083] For example, the green light-emitting materials involved in the second host material may include: coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N'-dimethylquinacridone (DMQA), 5,12-diphenylnaphthonaphthalene (DPT), N10,N10'-diphenyl-N10,N10'-diphthaloyl-9,9'-dianthracene-10,10'-diamine (abbreviated as: BA-NPB), etc.

[0084] The green light dopant involved is a green phosphorescent material. Exemplarily, the peak of the PL spectrum of the green phosphorescent material is 520nm-550nm. Exemplarily, the green phosphorescent material includes a heavy metal atom center and an organic conjugated group connected to the heavy metal atom center, wherein the heavy metal atom can be an Ir atom or a Pt atom, and the organic conjugated group can be a benzene ring group.

[0085] Exemplarily, the green phosphorescent material may include any one or more of tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), and di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)).

[0086] For the red light-emitting layer, the third host material involved may include any one or more of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidine-9-enyl)-4H-pyran (DCJTB).

[0087] The red light dopant involved is a red phosphorescent material having a PL spectrum peak range of 580nm-650nm. Exemplarily, the red phosphorescent material includes a heavy metal atom center and an organic conjugated group connected to the heavy metal atom center, wherein the heavy metal atom can be an Ir atom or a Pt atom, and the organic conjugated group can be a benzene ring group.

[0088] Exemplarily, the red phosphorescent material may include any one or more of: bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as: PtOEP), and bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetonate)iridium (abbreviated as: Ir(btp)2(acac)).

[0089] For the organic light-emitting unit, the thicknesses of the blue, red, and green light-emitting layers are set based on actual light-emitting requirements. For example, the thickness of the blue light-emitting layer can range from 10nm to 40nm; the thickness of the red light-emitting layer can range from 2nm to 20nm; and the thickness of the green light-emitting layer can range from 5nm to 30nm. Furthermore, the thickness of the interlayer can range from 2nm to 20nm.

[0090] In the embodiment of the present disclosure, the hole transport unit includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer; the electron transport unit includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer.

[0091] In some examples (1), the hole transport unit includes a hole transport layer, wherein the anode, the hole transport layer, and the organic light-emitting unit are stacked in sequence.

[0092] In some examples (2), the hole transport unit includes a hole injection layer and a hole transport layer, wherein the anode, the hole injection layer, the hole transport layer, and the organic light-emitting unit are stacked in sequence.

[0093] In some examples (3), the hole transport unit includes a hole transport layer and an electron blocking layer, wherein the anode, the hole transport layer, the electron blocking layer, and the organic light-emitting unit are stacked in sequence.

[0094] In some examples (4), the hole transport region includes a hole transport layer, an electron blocking layer and a hole injection layer, wherein the anode, the hole injection layer, the hole transport layer, the electron blocking layer and the organic light emitting unit are stacked in sequence.

[0095] In some examples (5), the electron transport region includes an electron transport layer, wherein the cathode, the electron transport layer, and the organic light-emitting unit are stacked in sequence.

[0096] In some examples (6), the electron transport region includes an electron transport layer and an electron injection layer, wherein the cathode, the electron injection layer, the electron transport layer, and the organic light-emitting unit are stacked in sequence.

[0097] In some examples (7), the electron transport region includes an electron transport layer and a hole blocking layer, wherein the cathode, the electron transport layer, the hole blocking layer, and the organic light-emitting unit are stacked in sequence.

[0098] In some examples (8), the electron transport region includes an electron transport layer, a hole blocking layer, and an electron injection layer, wherein the cathode, the electron injection layer, the electron transport layer, the hole blocking layer, and the organic light-emitting unit are stacked in sequence.

[0099] Among them, any example from the above examples (1) to (4) and any example from (5) to (8) can be combined arbitrarily, and will not be described one by one here.

[0100] In addition, the hole transport unit, the electron transport unit, the anode and the cathode may all be made of currently known related materials, which are exemplified below.

[0101] For the hole injection layer, one example may be an oxide of a metal such as molybdenum, titanium, vanadium, rhenium, ruthenium, chromium, zirconium, hafnium, tantalum, silver, tungsten, or manganese. Another example may be hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane, etc. In some examples, the thickness of the hole injection layer may be 3 nm to 20 nm.

[0102] The hole transport layer can be an aromatic amine or carbazole material, including but not limited to 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), NPB, TPD, BAFLP, DFLDPBi, etc. In some examples, the thickness of the hole transport layer can be 20 nm to 100 nm.

[0103] The electron blocking layer may be TCTA, mCBP, PCzPA, etc. In some examples, the thickness of the electron blocking layer may be 5 nm-100 nm.

[0104] The hole blocking layer and the electron transport layer are each independently selected from the following, including but not limited to: 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPDen), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs), BCP, TPBi, etc. In some examples, the thickness of the electron transport layer or the hole blocking layer is 3 nm to 50 nm.

[0105] The electron injection layer includes, but is not limited to, LiF, Yb, Mg, Ca, and oxides thereof, etc. In some examples, the thickness of the electron injection layer may be 0.5 nm to 5 nm.

[0106] The anode mentioned above may be a single-layer structure or a multi-layer structure. For a multi-layer structure, the anode includes a reflective layer and a transmissive conductive layer arranged in a stacked manner. The transmissive conductive layer may be made of ITO, IZO, ZnO, or ITZO, and the reflective layer may be made of a metal, a metal alloy, or a metal compound, for example, but not limited to: silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF / Ca, LiF / Al, molybdenum (Mo), titanium (Ti), and their alloys or compounds.

[0107] The cathode may be a transmissive electrode, a transflective electrode, or a reflective electrode. Transmissive electrodes may include transparent metal oxides such as ITO, IZO, ZnO, and ITZO. Transmissive or reflective electrodes may be made from materials including Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or compounds or alloys thereof.

[0108] The WOLED device provided by the embodiment of the present disclosure has an anode arranged on a substrate, wherein the substrate may be a silicon substrate, such as single crystal silicon, thereby forming a silicon-based WOLED device. The substrate may also be a glass substrate.

[0109] According to another aspect of the embodiments of the present disclosure, a display device is provided. The display device includes any one of the WOLED devices described above.

[0110] The display device provided by the embodiment of the present disclosure has all the advantages of the WOLED device provided by the embodiment of the present disclosure.

[0111] Exemplarily, the display device includes but is not limited to a mobile phone display, a computer display, a TV display, a smart watch display, a smart car display, a VR or AR helmet display, etc.

[0112] In some examples, in addition to the above-mentioned WOLED device, the display device may also include the necessary structures and components of the display device. Taking a mobile phone display as an example, it may also include a display backplane, a color film substrate, a glass cover, a housing, a touch panel, etc.

[0113] The specific embodiments of the present disclosure will be described in more detail below. Although the specific embodiments of the present disclosure are described below, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0114] Example 1

[0115] Example 1 provides a WOLED device, which includes a silicon substrate and a WOLED structure disposed on the silicon substrate. As shown in FIG1 , the WOLED structure includes an anode, a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, a blue light-emitting layer BEML, an interlayer IL1, a green light-emitting layer GEML, a red light-emitting layer REML, a hole blocking layer HBL, an electron transport layer ETL, an electron injection layer EIL, and a cathode, which are stacked in sequence.

[0116] The WOLED device is manufactured by the following method: providing a silicon substrate with multiple arrayed pixel regions, forming an anode on the silicon substrate, and sequentially forming the following layers on the anode using an evaporation process: HIL / HTL / EBL / BEML / IL1 / GEML / REML / HBL / ETL / EIL / Cathode. This is then followed by packaging and a back-end CF+Lens process to produce the WOLED device.

[0117] The composition of each layer in the WOLED device is as follows:

[0118] The anode is ITO with a thickness of 70nm; the cathode is Al with a thickness of 100nm.

[0119] The hole injection layer (HIL) is composed of a mixture of a p-type dopant (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene) and a host material (4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB)). The mass doping ratio of the p-type dopant is 2%, and the HIL thickness is 10 nm.

[0120] The hole transport layer HTL is 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) and has a thickness of 70 nm.

[0121] The electron blocking layer EBL is N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD) and has a thickness of 5 nm.

[0122] The blue light-emitting layer BEML is composed of a first host material: 9,10-di-(2-naphthyl)anthracene (ADN) and a blue light dopant: 4,4'-bis[4-(di-p-tolylamino)phenyl]biphenyl (DPAVBi), wherein the mass doping ratio of the blue light dopant is 1% and the thickness is 20nm.

[0123] The spacer IL1 is PBD, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, with a thickness of 5nm. The spacer IL1 meets the following conditions: electron mobility μ e =7.6×10 -5 cm 2 / Vs, |HOMO|=6.01eV.

[0124] The green light-emitting layer GEML is composed of a second host material: 5,12-diphenylnaphthacene (DPT) and a green light dopant: tris(2-phenylpyridine)iridium (Ir(ppy)3), wherein the mass doping ratio of the green light dopant is 10% and the thickness is 10nm.

[0125] The red light-emitting layer REML is composed of a third main material: 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenylvinyl)-4H-pyran (DCM) and a red light dopant: di(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), wherein the mass doping ratio of the red light dopant is 2% and the thickness is 5nm.

[0126] The hole blocking layer HBL is 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and has a thickness of 5 nm.

[0127] The electron transport layer ETL is 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ) and has a thickness of 30 nm.

[0128] The electron injection layer EIL is made of metal Yb and has a thickness of 1 nm.

[0129] Comparative Example 1

[0130] Comparative Example 1 provides a comparative WOLED device for Example 1. The difference between the WOLED device and Example 1 lies in the difference in the type of interlayer. Specifically, the interlayer is the interlayer IL2 in Example 2 below.

[0131] Example 2

[0132] Example 2 provides a WOLED device, which includes a silicon substrate and a WOLED structure disposed on the silicon substrate. As shown in FIG2 , the WOLED structure includes an anode, a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, a red light-emitting layer REML, an interlayer IL2, a blue light-emitting layer BEML, a green light-emitting layer GEML, a hole blocking layer HBL, an electron transport layer ETL, an electron injection layer EIL, and a cathode, which are stacked in sequence.

[0133] The WOLED device is manufactured by the following method: providing a silicon substrate with multiple arrayed pixel regions, forming an anode on the silicon substrate, and sequentially forming the following layers on the anode using an evaporation process: HIL / HTL / EBL / REML / IL1 / BEML / GEML / HBL / ETL / EIL / Cathode. This is then followed by packaging and a back-end CF+Lens process to produce the WOLED device.

[0134] In this WOLED device, the composition and thickness of the anode, cathode, hole injection layer, hole transport layer, electron blocking layer, blue light-emitting layer, green light-emitting layer, red light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer are the same as those of the corresponding layers in Example 1, except that the spacer IL2 is different. Specifically, the spacer IL2 is TAPC, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], and has a thickness of 5 nm. The spacer IL2 meets the following conditions: the electron mobility μ e =8.23×10 -5 cm 2 / Vs, |LUMO|=2.48eV.

[0135] Comparative Example 2

[0136] Comparative Example 2 provides a comparative WOLED device for Example 2. The difference between this WOLED device and Example 2 is that the interlayer is different. Specifically, the interlayer is the interlayer IL1 in Example 1.

[0137] Test Case

[0138] In this test example, the electroluminescence spectra (EL spectra) of the WOLED devices provided in Example 1 and Comparative Example 1, and the WOLED devices provided in Example 2 and Comparative Example 2 were tested.

[0139] Figure 3 shows the EL spectrum test results of the WOLED devices provided in Example 1 and Comparative Example 1. As shown in Figure 3, in the WOLED device provided in Example 1, the blue, green, and red light-emitting layers each emit peaks in their respective wavelength bands, with relatively consistent peak intensities, thereby achieving balanced RGB tri-color emission. In contrast, in Comparative Example 1, the blue light-emitting layer exhibits no peak, meaning it emits no light. Furthermore, the peak value of the red light-emitting layer is significantly higher than that of the green light-emitting layer, failing to achieve balanced RGB tri-color emission.

[0140] Figure 4 shows the EL spectrum test results for the WOLED devices provided in Example 2 and Comparative Example 2. As shown in Figure 4, in the WOLED device provided in Example 2, the blue, green, and red light-emitting layers each emit peaks in their respective wavelength bands, and the peak intensities are relatively consistent, thus achieving balanced RGB tri-color emission. In contrast, in Comparative Example 2, although the blue and green light-emitting layers exhibit peaks, the peak intensities are relatively low. Furthermore, the peak value of the red light-emitting layer is much higher than that of the blue and green light-emitting layers, failing to achieve balanced RGB tri-color emission.

[0141] This test example also tested the device lifespan of the WOLED devices provided in Examples 1-2 and Comparative Examples 1-2. The device lifespan was characterized by LT95@1000nit, which refers to the time required for the brightness of the WOLED device to decay to 95% of the initial brightness based on an initial brightness of 1000nit.

[0142] The test results are shown in Table 1, where the data for Comparative Example 1 was normalized based on the data for Example 1, and the data for Comparative Example 2 was normalized based on the data for Example 2. As shown in Table 1, the WOLED devices provided in Examples 1-2 exhibited superior device lifespans compared to the WOLED devices provided in Comparative Examples 1-2.

[0143] Table 1

[0144] In the embodiments of the present disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0145] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solutions of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A WOLED device, wherein: The WOLED device comprises: an anode, a hole transport unit, an organic light emitting unit, an electron transport unit and a cathode which are stacked in sequence; The organic light-emitting unit includes: a blue light-emitting layer, a spacer, a green light-emitting layer and a red light-emitting layer stacked in sequence, the blue light-emitting layer is further stacked with the hole transport unit, and the red light-emitting layer is further stacked with the electron transport unit; The spacer has electron transport characteristics, and |HOMO| of the spacer is greater than or equal to a first set threshold.

2. The WOLED device according to claim 1, wherein: The spacer satisfies the following conditions: electron mobility μ e 1×10 -6 cm 2 / Vs~1×10 -4 cm 2 / Vs, and |HOMO|≥6.01eV.

3. The WOLED device according to claim 2, wherein: The interlayer is made of at least one of the following materials:

4. The WOLED device according to any one of claims 1 to 3, wherein: The blue light emitting layer includes a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%; The green light emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%; The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%.

5. The WOLED device according to claim 3, wherein: The first host material is at least one of a pyrene derivative blue luminescent material, anthracene derivative blue luminescent material, fluorene derivative blue luminescent material, and perylene derivative blue luminescent material, and the blue light dopant is a blue fluorescent material; The second host material is at least one of a coumarin dye, a quinacridone copper derivative green luminescent material, a polycyclic aromatic hydrocarbon green luminescent material, a diamine anthracene derivative green luminescent material, a carbazole derivative green luminescent material, and a metal complex green luminescent material, and the green light dopant is a green phosphorescent material; The third host material is at least one of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran and 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulonitrile-9-enyl)-4H-pyran, and the red light dopant is a red phosphorescent material.

6. A WOLED device, wherein: The WOLED device comprises: an anode, a hole transport unit, an organic light emitting unit, an electron transport unit and a cathode which are stacked in sequence; The organic light-emitting unit includes: a red light-emitting layer, a spacer, a blue light-emitting layer and a green light-emitting layer stacked in sequence, the red light-emitting layer is further stacked with the hole transport unit, and the green light-emitting layer is further stacked with the electron transport unit; The spacer has hole transport characteristics, and the |LUMO| of the spacer is less than or equal to a second set threshold.

7. The WOLED device according to claim 6, wherein: The interlayer satisfies the following conditions: hole mobility μ h 1×10 -5 cm 2 / Vs~1×10 -4 cm 2 / Vs, and |LUMO|≤2.48eV.

8. The WOLED device according to claim 7, wherein: The interlayer is made of at least one of the following materials:

9. The WOLED device according to any one of claims 6 to 8, wherein: The blue light emitting layer includes a first host material and a blue light dopant, and the mass percentage of the blue light dopant is 1%-5%; The green light emitting layer includes a second host material and a green light dopant, and the mass percentage of the green light dopant is 5%-15%; The red light emitting layer includes a third host material and a red light dopant, and the mass percentage of the red light dopant is 1%-5%.

10. The WOLED device according to claim 9, wherein: The first host material is at least one of a pyrene derivative blue luminescent material, anthracene derivative blue luminescent material, fluorene derivative blue luminescent material, and perylene derivative blue luminescent material, and the blue light dopant is a blue fluorescent material; The second host material is at least one of a coumarin dye, a quinacridone copper derivative green luminescent material, a polycyclic aromatic hydrocarbon green luminescent material, a diamine anthracene derivative green luminescent material, a carbazole derivative green luminescent material, and a metal complex green luminescent material, and the green light dopant is a green phosphorescent material; The third host material is at least one of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenyl)-4H-pyran and 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulonitrile-9-enyl)-4H-pyran, and the red light dopant is a red phosphorescent material.

11. A display device, wherein: The display device comprises the WOLED device according to any one of claims 1 to 10.

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