Light-emitting device, method for manufacturing the same, and display apparatus

Abstract

The application discloses a light-emitting device and a preparation method thereof and a display device. The preparation method of the light-emitting device is characterized in that a first substance is arranged on the surface of a cathode far from an electron transport layer, and a prefabricated device is powered on to form at least one silver channel in the electron transport layer, so that the electrons in the cathode can be transmitted to the light-emitting layer through the silver channel, thereby effectively improving the electron injection efficiency and improving the performance of the light-emitting device such as the service life and the light-emitting efficiency.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light-emitting device, its preparation method, and a display device. Background Technology

[0002] QLED (quantum dot light-emitting diode) is a widely researched display device. Its structure typically includes a stacked structure consisting of a hole transport layer, a light-emitting layer, and an electron transport layer. QLED devices have advantages such as excellent luminous performance, long lifespan, and simple packaging process, and have broad development prospects.

[0003] However, current QLED devices still have a large potential barrier at the interface between the light-emitting layer and the electron transport layer, which leads to insufficient electron injection. Moreover, the zinc oxide and other oxide nanocrystalline materials in the electron transport layer have a high work function contact with the quantum dots, which leads to interfacial charge transport at the interface between the electron transport layer and the light-emitting layer. This can also cause quantum dot quenching, resulting in an imbalance between electron and hole injection, and thus reducing the luminous efficiency and lifetime of QLEDs. Summary of the Invention

[0004] In view of this, this application provides a light-emitting device and a method for fabricating the same, as well as a display device, with the aim of improving the device performance of the light-emitting device.

[0005] This application provides a method for fabricating a light-emitting device, comprising: providing a pre-fabricated device, the pre-fabricated device including an anode, a light-emitting layer, a first electron transport layer, and a cathode; disposing a first material on the surface of the cathode away from the first electron transport layer, wherein the first material contains silver; energizing the pre-fabricated device to form at least one silver channel in the first electron transport layer, thereby forming a light-emitting device including a second electron transport layer; wherein, in the second electron transport layer, the silver channel extends from the cathode to the light-emitting layer.

[0006] Optionally, in some embodiments of this application, the material of the first electron transport layer is an electron transport material, and the material of the silver channel includes a mixture of silver and the electron transport material; and / or the cathode is a silver electrode; and / or the thickness of the cathode is 80-120 nm; and / or the thickness of the electron transport layer is 20-40 nm; and / or the mass ratio of the first substance to the area of ​​the cathode is 75-500 μg / cm². 2 .

[0007] Optionally, in some embodiments of this application, the first substance is selected from at least one of silver tetrafluoroborate, silver pentafluoropropionate, silver heptafluorobutyrate, silver hexafluorophosphate, and silver acrylate; and / or the mass ratio of said silver in the second electron transport layer is 1.5 to 4%.

[0008] Optionally, in some embodiments of this application, the step of applying the first substance to the surface of the cathode on the side away from the electron transport layer includes: applying a solution of the first substance to the surface of the cathode on the side away from the electron transport layer by a solution method, and then drying it.

[0009] Optionally, in some embodiments of this application, the solvent of the first substance solution is selected from at least one of diethyl ether, benzene, toluene, and nitromethane; and / or the concentration range of the first substance in the first substance solution is 5-20 mg / mL; and / or the drying temperature is 60-100°C and the time is 10-30 min; and / or before the drying, the process further includes: standing for 30-240 s.

[0010] Optionally, in some embodiments of this application, before energizing the prefabricated device, the process further includes: encapsulating the prefabricated device; and / or energizing at a voltage of 5-12V.

[0011] Optionally, in some embodiments of this application, the material of the electron transport layer is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials; the inorganic nanocrystalline material is selected from one or more of zinc oxide, titanium dioxide, tin dioxide, aluminum oxide, calcium oxide, silicon dioxide, gallium oxide, zirconium oxide, nickel oxide, and zirconium trioxide; the doped inorganic nanocrystalline material includes the inorganic nanocrystalline material and a doping element, wherein the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, and Mn; and / or the material of the light-emitting layer is selected from quantum dot materials, wherein the quantum dot materials are selected from at least one of single-structure quantum dots, core-shell structure quantum dots, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots, wherein the single-structure quantum dots are selected from group II-VI compounds, The group comprises at least one of group III-V compounds, group II-V compounds, group III-VI compounds, group IV-VI compounds, group I-III-VI compounds, group II-IV-VI compounds, and group IV elements, wherein the group II-VI compounds are selected from at least one of CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, CdZnSeTe, and CdZnSTe, and the group III-V compounds are selected from InP, InAs, GaP, GaAs, and CdS. At least one of GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP, and InAlNP, wherein the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot is selected from any one of the single-structure quantum dots, and the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, and ZnS; the general structural formula of the inorganic perovskite quantum dot is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2 + Yb 2+ Eu 2+At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite quantum dot is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH 3+ Or NH3(CH2) n NH3 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I -At least one of the following: and / or the anode is selected from one or more of a metal electrode, a carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein the metal electrode is made of at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the carbon electrode is made of at least one of graphite, carbon nanotubes, graphene, and carbon fiber; the doped or undoped metal oxide electrode is made of at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; and the composite electrode is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2. At least one of TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or the prefabricated device further includes a hole functional layer disposed between the anode and the light-emitting layer, the hole functional layer including a hole injection layer and / or a hole transport layer; when the hole functional layer includes both the hole injection layer and the hole transport layer, the hole injection layer is disposed closer to the anode, and the hole transport layer is disposed closer to the light-emitting layer; the material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N- Phenyl-1,4-phenylenediamine), 4,4',4”-tris(carbazole-9-yl)triphenylamine, 4,4'-di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), Spiro-NPB, Spiro-TPD, doped or undoped NiO, MoO3, WO3, V2O5, p-type gallium nitride, CrO3 One or more of CuO, MoS2, MoSe2, WS3, WSe3, CuS, and CuSCN; and / or the material of the hole injection layer is selected from one or more of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, copper phthalocyanine, transition metal oxides, and transition metal chalcogenides; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO;The metal chalcogenide compounds include one or more selected from MoS2, MoSe2, WS3, WSe3, and CuS.

[0012] Accordingly, this application also provides a light-emitting device, including a stacked anode, a light-emitting layer, an electron transport layer and a cathode, wherein the electron transport layer includes at least one silver channel that extends from the cathode to the light-emitting layer.

[0013] Optionally, in some embodiments of this application, the electron transport layer is made of an electron transport material, and the silver channel is made of a mixture of silver and the electron transport material; and / or one or more of the at least one silver channel connects the cathode and the light-emitting layer; and / or the contact area between each silver channel and the cathode is 1–9 nm. 2 ; and / or the mass ratio of silver in the electron transport layer is 1.5 to 4%.

[0014] Optionally, in some embodiments of this application, the cathode is a silver electrode; and / or the thickness of the cathode is 80-120 nm; and / or the material of the electron transport layer is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials; the inorganic nanocrystalline material is selected from one or more of zinc oxide, titanium dioxide, tin dioxide, aluminum oxide, calcium oxide, silicon dioxide, gallium oxide, zirconium oxide, nickel oxide, and zirconium trioxide; the doped inorganic nanocrystalline material includes the inorganic nanocrystalline material and a doping element, wherein the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, and Mn; and / or the thickness of the electron transport layer is 20-40 nm; and / or the material of the light-emitting layer is selected from quantum dot materials, wherein the quantum dot materials are selected from at least one of single-structure quantum dots, core-shell structure quantum dots, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots, wherein the single-structure quantum dots are selected from II-VI group compounds, III-V group compounds, III-VI group compounds, IV-VI group compounds, etc. The group I-VI compounds are selected from at least one of group II-VI compounds, group III-VI compounds, group II-IV-VI compounds, and group IV elements, wherein the group II-VI compounds are selected from at least one of CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, CdZnSeS, CdZnSTe, and CdZnSTe; and the group III-V compounds are selected from at least one of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP, and InAlNP. At least one of the group I-III-VI compounds is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot is selected from any one of the single-structure quantum dots; the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, and ZnS; the general structural formula of the inorganic perovskite quantum dot is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite quantum dot is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH 3+ Or NH3(CH2) n NH3 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I -At least one of the following; and / or the anode is selected from one or more of a metal electrode, a carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene, and carbon fibers; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; the composite electrode is selected from AZO / Ag / AZO, At least one of AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or the light-emitting device further includes a hole functional layer; the hole functional layer includes a hole injection layer and / or a hole transport layer; when the hole functional layer includes both the hole injection layer and the hole transport layer, the hole injection layer is disposed closer to the anode, and the hole transport layer is disposed closer to the light-emitting layer; the material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole, poly(N,N'-bis(4-butylphenyl)-N,N'- Bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine), 4,4',4”-tris(carbazole-9-yl)triphenylamine, 4,4'-di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), Spiro-NPB, Spiro-TPD, doped or undoped NiO, The material of the hole injection layer is selected from one or more of the following: MoO3, WO3, V2O5, p-type gallium nitride, CrO3, CuO, MoS2, MoSe2, WS3, WSe3, CuS, and CuSCN; and / or the material of the hole injection layer is selected from one or more of the following: poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, copper phthalocyanine, transition metal oxides, and transition metal chalcogenides; wherein the transition metal oxides include one or more of the following: NiO, MoO2, WO3, and CuO.The metal chalcogenide compounds include one or more selected from MoS2, MoSe2, WS3, WSe3, and CuS.

[0015] Accordingly, embodiments of this application also provide a display device, the display device comprising a light-emitting device prepared by the above-described method for preparing a light-emitting device; or the display device comprising the above-described light-emitting device.

[0016] The method for fabricating the light-emitting device disclosed in this application involves disposing the first material on the surface of the cathode away from the electron transport layer and energizing the pre-fabricated device to form at least one silver channel in the electron transport layer. Electrons in the cathode can be transferred to the light-emitting layer through the silver channel, thereby effectively improving the electron injection efficiency. The silver channel in the electron transport layer connects to the light-emitting layer, which also effectively reduces the energy barrier at the interface between the light-emitting layer and the electron transport layer, facilitating the entry of electrons from the electron transport layer into the light-emitting layer. This reduces the turn-on voltage of the light-emitting device, improves the injection balance of electrons and holes, and enhances the lifetime and luminous efficiency of the light-emitting device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of an embodiment of a method for fabricating a light-emitting device provided in this application;

[0019] Figure 2 This is a schematic diagram of the structure of an embodiment of a light-emitting device provided in this application;

[0020] Figure 3a and Figure 3b The figures show the operating voltage-time curves and current density-voltage curves of the single electronic devices (EODs) in Comparative Examples 1-3, respectively.

[0021] Figure 4a and Figure 4b The figures show the operating voltage-time curves and current density-voltage curves for the single electronic devices (EODs) in Examples 1-4, respectively.

[0022] Figure 5a and Figure 5b The figures show the operating voltage-time curves and current density-voltage curves of the single electronic devices (EODs) in Examples 5-7, respectively.

[0023] Figure 6a and Figure 6b The figures show the operating voltage-time curve and the current density-voltage curve of the hole device (HOD) in Example 1, respectively.

[0024] Figure 7 This is a TEM image of the single electronic device in Example 1. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0026] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operation, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to".

[0027] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0028] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0029] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0030] Please see Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of a method for fabricating a light-emitting device provided in this application, including the following steps:

[0031] Step S11: Provide a prefabricated device, the prefabricated device including an anode, a light-emitting layer, a first electron transport layer and a cathode;

[0032] Step S12: A first substance is disposed on the surface of the cathode on the side away from the first electron transport layer, wherein the first substance contains silver ions;

[0033] Step S13: Power on the prefabricated device to form a silver channel in the first electron transport layer, thereby obtaining a light-emitting device containing a second electron transport layer.

[0034] In the second electron transport layer, the silver channel extends from the cathode to the light-emitting layer.

[0035] The method for fabricating the light-emitting device in this embodiment involves placing the first material on the surface of the cathode away from the first electron transport layer and energizing the pre-fabricated device to form at least one silver channel in the first electron transport layer. Electrons in the cathode can be transferred to the light-emitting layer through the silver channel, thereby effectively improving the electron injection efficiency.

[0036] Furthermore, the silver channel extends from the cathode to the light-emitting layer, connecting with and linking the cathode and the light-emitting layer. This effectively reduces the energy barrier at the interface between the light-emitting layer and the electron transport layer, facilitating electron entry from the electron transport layer into the light-emitting layer and thus lowering the turn-on voltage of the light-emitting device. Specifically, the silver channel promotes electron transport at the interface between the light-emitting layer and the electron transport layer, thereby suppressing electro-induced recombination emission and improving device performance. As a highly conductive path, the silver channel provides a rapid electron injection channel, promoting rapid electron injection and improving the electron-hole injection balance. On the other hand, the silver channel effectively reduces the energy barrier at the interface between the light-emitting layer and the electron transport layer, promoting electron transport into the light-emitting layer and thus lowering the turn-on voltage of the light-emitting device. Additionally, the silver channel effectively promotes the interaction between the cathode and the electron transport layer, significantly shortening the forward aging time of the light-emitting device.

[0037] In step S11:

[0038] The cathode is a silver (Ag) electrode. The thickness of the cathode can be 80-120 nm, specifically 80-110 nm, 80-100 nm, 80-90 nm, 90-110 nm, 90-100 nm, etc.

[0039] The material of the light-emitting layer is selected from quantum dot materials. The quantum dot materials are selected from at least one of the following: single-structure quantum dots, core-shell structure quantum dots, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots. The single-structure quantum dots are selected from at least one of group II-VI compounds, group III-V compounds, group II-V compounds, group III-VI compounds, group IV-VI compounds, group I-III-VI compounds, group II-IV-VI compounds, and group IV elements. The group II-VI compounds are selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, At least one of ZnTeS, CdSeS, CdSeTe, CdTeS, CdZnSeS, CdZnSeTe, and CdZnSTe, wherein the III-V group compound is selected from at least one of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP, and InAlNP, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot is selected from any one of the single-structure quantum dots, and the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, and ZnS; the general structural formula of the inorganic perovskite quantum dot is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite quantum dot is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH 3+ Or NH3(CH2) n NH3 2+ Where n≥2, M is a divalent metal cation selected from Pb2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them.

[0040] In one specific embodiment, the material of the light-emitting layer is selected from blue quantum dot materials. Accordingly, the light-emitting device is a blue quantum dot light-emitting device. In the blue quantum dot light-emitting device, the silver channel is formed in the electron transport layer by the fabrication method provided in this application, which promotes electron injection and reduces the potential barrier at the interface between the light-emitting layer and the electron transport layer, thereby improving the problems of insufficient electron injection and high turn-on voltage, improving the injection balance of electrons and holes, and improving the luminous efficiency and lifetime of the blue quantum dot light-emitting device.

[0041] The material of the electron transport layer is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials; the inorganic nanocrystalline materials are selected from one or more of zinc oxide, titanium dioxide, tin dioxide, aluminum oxide, calcium oxide, silicon dioxide, gallium oxide, zirconium oxide, nickel oxide, and zirconium trioxide; the doped inorganic nanocrystalline materials include the inorganic nanocrystalline materials and doping elements, and the doping elements are selected from at least one of Mg, Ca, Li, Ga, Al, Co, and Mn.

[0042] The thickness of the electron transport layer can be 20-40 nm, specifically 20-35 nm, 20-30 nm, 20-25 nm, 25-40 nm, 25-35 nm, 25-30 nm, 30-40 nm, 30-35 nm, 35-40 nm, etc. This thickness range of electron transport layer can support the formation of the silver channels therein, enabling the light-emitting device to have good electron transport and injection performance.

[0043] The anode is selected from one or more of the following: metal electrode, carbon electrode, doped or undoped metal oxide electrode, and composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene, and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; and the composite electrode is selected from at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. In this context, " / " indicates a stacked structure. For example, the composite electrode AZO / Ag / AZO represents an electrode with a three-layer stacked structure consisting of an AZO layer, an Ag layer, and an AZO layer.

[0044] In step S12:

[0045] The first substance is selected from at least one of silver tetrafluoroborate, silver pentafluoropropionate, silver heptafluorobutyrate, silver hexafluorophosphate, and silver acrylate. The first substance not only provides silver ions to form silver channels but also has a certain etching effect on the silver electrode, promoting the passage of silver ions through the silver electrode to the first electron transport layer.

[0046] Understandably, the mass of the first substance disposed on the surface of the cathode can be set according to the area of ​​the cathode surface. For example, in one embodiment, the ratio of the mass of the first substance to the area of ​​the cathode is 75–500 μg / cm². 2 Specifically, it can be 75–100 μg / cm³. 2 100~200μg / cm 2 200~300μg / cm 2 300~400μg / cm 2 400~500μg / cm 2 75~450 μg / cm 2 100~350μg / cm 2 150~350μg / cm 2 250~350μg / cm 2 wait.

[0047] In another embodiment, the mass of the first substance disposed on the surface of the cathode can be determined based on the area of ​​the first electron transport layer adjacent to the cathode. Specifically, the ratio of the mass of the first substance to the area of ​​the first electron transport layer is 75–500 μg / cm². 2 Specifically, it can be 75–100 μg / cm³. 2 100~200μg / cm 2 200~300μg / cm 2 300~400μg / cm 2 400~500 μg / cm 2 75~450μg / cm 2 100~350μg / cm 2 150~350μg / cm 2 250~350μg / cm 2 wait.

[0048] In the two embodiments described above, the mass of the first substance is determined based on the area of ​​the cathode or the first electron transport layer, thereby enabling sufficient amounts of the first substance to be deposited on the surface of the cathode.

[0049] In one embodiment, the step of applying a first substance to the surface of the cathode on the side away from the first electron transport layer specifically includes the following steps: applying a solution of the first substance to the surface of the cathode on the side away from the first electron transport layer by a solution method, and then drying it.

[0050] The solution method can be spin coating, printing, inkjet printing, blade coating, printing, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating, etc.

[0051] The concentration range of the first substance in the first substance solution can be 5-20 mg / mL, specifically 5-15 mg / mL, 5-10 mg / mL, 10-20 mg / mL, 10-15 mg / mL, 15-20 mg / mL, etc. This concentration range allows the first substance to be uniformly spread on the surface of the first electron transport layer.

[0052] The volume of the first substance solution disposed on the surface of the cathode can be set according to the area of ​​the cathode surface. For example, in one embodiment, the ratio of the volume of the first substance solution to the area of ​​the cathode is 15–25 μL / cm². 2 Specifically, it can be 15–22 μL / cm 2 18~22 μL / cm 2 18~20μL / cm2 15~18μL / cm 2 22~25μL / cm 2 wait.

[0053] In another embodiment, the volume of the first substance solution disposed on the surface of the cathode can be determined based on the area of ​​the first electron transport layer adjacent to the cathode. Specifically, the ratio of the volume of the first substance solution to the area of ​​the first electron transport layer is 15–25 μL / cm². 2 Specifically, it can be 15–22 μL / cm 2 18~22μL / cm 2 18~20μL / cm 2 15~18μL / cm 2 22~25μ L / cm 2 wait.

[0054] In the two embodiments described above, the volume of the first substance solution is determined based on the area of ​​the cathode or the first electron transport layer, thereby enabling sufficient amounts of the first substance to be disposed on the surface of the cathode.

[0055] The solvent for the first substance solution is selected from at least one of diethyl ether, benzene, toluene, and nitromethane.

[0056] The drying temperature is 60-100℃, and the time is 10-30 minutes. Specifically, the drying temperature can be 60-90℃, 70-100℃, 70-90℃, 70-80℃, etc.; the drying time can be 10-25 minutes, 15-30 minutes, 15-25 minutes, 15-20 minutes, etc. Through this drying process, the solvent in the first substance solution can be evaporated and removed, while also promoting a tighter contact between the first substance and the cathode.

[0057] The process includes a settling period before drying. The settling time is 30-240 seconds, specifically 30-200 seconds, 60-240 seconds, 80-200 seconds, 80-150 seconds, 90-150 seconds, 90-120 seconds, etc., to allow the first substance in the first substance solution to fully contact and penetrate the cathode, thereby forming a silver channel in subsequent steps.

[0058] In one specific embodiment, the step of depositing a first material on the surface of the cathode away from the first electron transport layer specifically includes the following steps:

[0059] A silver tetrafluoroborate-diethyl ether solution was dropped onto the surface of the cathode on the side away from the first electron transport layer. After standing for 30-240 seconds, the solution was spin-coated and dried. The cathode was then heated at 80°C for 30 minutes and then encapsulated.

[0060] In step S13:

[0061] The prefabricated device is energized to allow the silver ions to pass through the cathode to reach the first electron transport layer, and to reduce the silver ions to silver atoms, thereby forming a silver channel in the first electron transport layer, and forming a second electron transport layer containing at least one of the silver channels, thus obtaining the light-emitting device.

[0062] Understandably, the material of the first electron transport layer is an electron transport material, while in the second electron transport layer, the material of the silver channel can be a mixture of silver and the electron transport material, and the material of the region other than the silver channel is the electron transport material.

[0063] The term "energizing the prefabricated device" specifically refers to connecting the anode and cathode of the prefabricated device to the positive and negative terminals of a power supply, respectively, thereby energizing the prefabricated device. In other words, it means applying an external voltage to the prefabricated device.

[0064] The voltage applied can be 5-12V, specifically 5-10V, 5-8V, 8-12V, 8-10V, 10-12V, etc. The applied voltage can be the same as the voltage range in which the light-emitting device operates normally.

[0065] When the prefabricated device is energized, silver ions in the first material on the cathode surface drift towards the anode under the guidance of the current. In the first electron transport layer, due to the low migration rate of silver ions in inorganic nanocrystalline materials such as ZnO, the silver ion (Ag)... +After a short distance of migration, silver ions are reduced to silver atoms (Ag). As the oxidation / reduction process continues, silver atoms accumulate at the interface between the cathode and the first electron transport layer, leading to an enhanced electric field. This further promotes the continued migration of silver ions towards the anode. As silver ions continue to migrate and are simultaneously reduced to silver atoms, the enhanced electric field further promotes their migration, causing the channels for silver atoms in the first electron transport layer to grow continuously, forming silver channels. These silver channels extend from the cathode towards the light-emitting layer, facilitating rapid electron injection and transport, improving the luminous efficiency of the light-emitting device, reducing the turn-on voltage, and increasing the lifespan of the device. In one specific embodiment, the silver channels continue to grow until they connect with the interface between the first electron transport layer and the light-emitting layer, forming a silver channel connecting the interface between the cathode and the light-emitting layer. This further promotes rapid electron injection and transport, improving the luminous efficiency of the light-emitting device, reducing the turn-on voltage, and increasing the lifespan of the device.

[0066] In the second electron transport layer formed, which includes at least one of the silver channels, the mass ratio of silver is 1.5 to 4%, specifically 1.5 to 3.5%, 2.0 to 3.5%, 2.0 to 3.0%, 2.5 to 3.0%, 2.5 to 3.5%, 3.5 to 4.0%, 2.0 to 4.0%, 3.5 to 4.0%, 1.5 to 2.5%, 1.5 to 3.0%, etc.

[0067] After step S12 and before step S13, the process further includes encapsulating the prefabricated device. If the encapsulation is performed before step S13, then step S13 is: powering on the encapsulated prefabricated device. The encapsulation can refer to conventional encapsulation operations in the art.

[0068] In one embodiment, the encapsulation of the prefabricated device may specifically include: applying encapsulating adhesive to the prefabricated device, then placing a cover plate on the encapsulating adhesive on the prefabricated device, and then curing it.

[0069] The encapsulating adhesive can be an encapsulating material such as acrylic resin or epoxy resin. When the encapsulating adhesive is a UV-curable encapsulating adhesive, the curing process can be as follows: curing under a UV lamp for 15 to 30 minutes.

[0070] In some embodiments, the power supply can be used for lifetime testing or aging testing of the device. That is, after the prefabricated device is packaged to obtain an initial light-emitting device, during lifetime testing or aging testing of the initial light-emitting device, under the action of voltage, silver ions on the cathode surface drift towards the anode under the guidance of current and are reduced in the first electron transport layer to form silver channels.

[0071] After fabrication, light-emitting devices typically require a period of time for lifetime testing to promote positive aging and improve their lifespan. The mechanism of positive aging may involve the interaction between the electron transport material and the cathode. In this embodiment, by constructing the silver channel in the first electron transport layer, the interaction between the cathode and the second electron transport layer can be effectively promoted, thereby significantly shortening the positive aging time of the light-emitting device and simultaneously improving its lifespan.

[0072] In one embodiment, the material of the light-emitting layer is selected from quantum dot materials, and the electron transport material is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials, such as zinc oxide. The inorganic nanocrystalline material (or doped inorganic nanocrystalline material) has a high work function contact with the quantum dot material (especially blue quantum dot materials), and the interfacial charge transport can cause the quantum dot material to quench, thereby reducing efficiency. Furthermore, in the inorganic nanocrystalline material or doped inorganic nanocrystalline material, oxygen ion defects and oxygen vacancies are more mobile than cations (such as zinc ions) under an external electric field, thus causing oxygen ions (O...) to... in the first electron transport layer due to the electric field. 2- Due to the repulsive force of oxygen vacancies, oxygen vacancies will accumulate in the cathode. Once a sufficient concentration of oxygen vacancies accumulates near the cathode, it will cause difficulties in electron injection into the light-emitting device, resulting in increased resistance and a higher turn-on voltage.

[0073] In this application, the silver channel is formed in the first electron transport layer. Silver atoms are also easily doped in inorganic nanocrystalline materials or doped inorganic nanocrystalline materials, such as zinc oxide, where silver doping is easily formed, and they easily form dopants that substitute for Zn sites, thereby suppressing other intrinsic donor doping (such as oxygen vacancies or interstitial doping). At the same time, the formation energy of oxygen vacancies in silver-doped zinc oxide unit cells is relatively high, making it difficult for oxygen vacancies to form. Therefore, forming the silver channel in the first electron transport layer can effectively reduce oxygen defects in the first electron transport layer, prevent oxygen holes from accumulating near the cathode, and lower the energy barrier at the interface between the light-emitting layer and the first electron transport layer, promoting electron transfer into the light-emitting layer, improving electron injection and transport efficiency, reducing quenching of quantum dot materials, thereby improving luminous efficiency and reducing the turn-on voltage of the light-emitting device.

[0074] It is understood that when the light-emitting device further includes a hole functional layer, step S11 is: providing a prefabricated device, wherein the prefabricated device is a composite of an anode, a hole functional layer, a light-emitting layer, a first electron transport layer, and a cathode.

[0075] Furthermore, the hole functional layer includes a hole injection layer and / or a hole transport layer. When the hole functional layer includes both a hole injection layer and a hole transport layer, the hole injection layer is disposed closer to the anode, and the hole transport layer is disposed closer to the light-emitting layer.

[0076] The hole transport layer is made of materials selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) (TFB), polyvinylcarbazole (PVK), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)biphenylamine) (poly-TPD), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine) (PFB), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCATA), 4,4'-bis(9-carbazole)biphenyl (CBP), N,N'-diphenyl-N,N'- Di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS), Spiro-NPB, Spiro-TPD, or one or more of the following: doped or undoped NiO, MoO3, WO3, V2O5, p-type gallium nitride, CrO3, CuO, MoS2, MoSe2, WS3, WSe3, CuS, and CuSCN.

[0077] The material of the hole injection layer is a material with hole injection capability, selected from one or more of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethylethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HATCN), copper phthalocyanine (CuPc), transition metal oxides, and transition metal chalcogenides; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO; and the metal chalcogenides include one or more of MoS2, MoSe2, WS3, WSe3, and CuS.

[0078] It is understood that the light-emitting device may further include a substrate. In one embodiment, step S11 is: providing a pre-fabricated device, the pre-fabricated device including a stacked substrate, an anode, a hole functional layer, a light-emitting layer, a first electron transport layer, and a cathode. The light-emitting device obtained by the above-described method is a positive light-emitting device.

[0079] The substrate can be a rigid substrate or a flexible substrate. The rigid substrate can be a ceramic material or various glass materials, etc. The flexible substrate can be a substrate formed of materials such as polyimide film (PI) and its derivatives, polyethylene naphthalate (PEN), phosphoenolpyruvate (PEP), or diphenylene ether resin.

[0080] The fabrication method of the light-emitting device provided in this application, wherein the fabrication methods of the various film layers including the anode, hole functional layer, light-emitting layer, first electron transport layer, and cathode in the pre-fabricated device can be implemented using conventional techniques in the art, such as chemical methods or physical methods. Chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include physical deposition and solution methods. Physical deposition methods include thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods can include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating, etc.

[0081] It is understood that when the light-emitting device further includes an electron injection layer, a hole blocking layer, and / or an interface modification layer, the above two preparation methods also include the step of forming the corresponding layers using the above chemical or physical methods.

[0082] This application also relates to a light-emitting device, see reference. Figure 2 , Figure 2 This is a schematic diagram of an embodiment of a light-emitting device provided in this application. The light-emitting device 100 includes a cathode 10, an electron transport layer 20, a light-emitting layer 30, and an anode 40 stacked together. The electron transport layer 20 includes at least one silver channel 21, which extends from the cathode 10 to the light-emitting layer 30.

[0083] Furthermore, the silver channel 21 can be connected at one end to the cathode 10 and at the other end to the light-emitting layer 30. That is, one or more of the at least one silver channel 21 can connect the cathode and the light-emitting layer. It is understood that when the electron transport layer 20 includes one silver channel 21, the silver channel 21 extends from the cathode 10 to the light-emitting layer 30 and may or may not connect to the light-emitting layer 30. When the electron transport layer 20 includes two or more silver channels 21, all the silver channels 21 extend from the cathode 10 to the light-emitting layer 30, and some of the silver channels 21 may connect to the light-emitting layer 30 while others may not.

[0084] In this embodiment, the electron transport layer 20 of the light-emitting device 100 includes the silver channel 21. During operation, electrons in the cathode 10 can be transferred to the light-emitting layer 30 through the silver channel 21, thereby effectively improving the electron injection efficiency. The silver channel 21 in the electron transport layer 20 is connected to the light-emitting layer 30, which can also effectively reduce the energy barrier at the interface between the light-emitting layer 30 and the electron transport layer 20, facilitating the entry of electrons from the electron transport layer 20 into the light-emitting layer 30. This reduces the turn-on voltage of the light-emitting device 100, improves the electron and hole injection balance of the light-emitting device 100, and enhances the luminous efficiency and lifetime of the light-emitting device 100.

[0085] In one embodiment, the electron transport layer 20 is made of an electron transport material, and the silver channel 21 is made of a mixture of silver and the electron transport material. That is, the silver channel 21 is a portion of the electron transport layer 20, and there can be multiple silver channels 21, which are formed at intervals in the electron transport layer 20. The regions corresponding to the silver channels 21 all extend from the cathode 10 to the light-emitting layer 30.

[0086] The shape of the contact surface between each silver channel 21 and the cathode 10 can be a regular shape, such as a circle, rectangle, or square, or it can be an irregular shape, such as a cloud-like shape.

[0087] In one specific embodiment, the contact surface is square, and the side length of the square can be 1 to 3 nm. In another specific embodiment, when the contact surface is circular, the diameter of the circle can be 1 to 3 nm, etc.

[0088] In one embodiment, the contact area between each silver channel 21 and the cathode 10 can be 1–9 nm. 2 For example, 1-8nm 2 2-8nm 2 2-7nm2 3-7nm 2 3-6nm 2 4-6nm 2 4-5nm 2 wait.

[0089] In one embodiment, the mass ratio of silver in the electron transport layer 20 is 1.5-4%, specifically 1.5-3.5%, 2.0-3.5%, 2.0-3.0%, 2.5-3.0%, 2.5-3.5%, 3.5-4.0%, 2.0-4.0%, 3.5-4.0%, 1.5-2.5%, 1.5-3.0%, etc.

[0090] In one embodiment, the light-emitting device 100 further includes a hole functional layer 50. The hole functional layer 50 includes a hole injection layer 51 and / or a hole transport layer 52. When the hole functional layer 50 includes both a hole injection layer 51 and a hole transport layer 52, the hole injection layer 51 is disposed closer to the anode, and the hole transport layer 52 is disposed closer to the light-emitting layer.

[0091] In this embodiment, the cathode 10, electron transport layer 20, light-emitting layer 30, anode 40, hole functional layer 50, silver channel 21, etc., can be referred to the relevant descriptions in the fabrication method of the light-emitting device above, and will not be repeated here. Specifically, the electron transport layer 20 can be referred to the relevant descriptions of the first electron transport layer and the second electron transport layer in the fabrication method of the light-emitting device above, and will not be repeated here.

[0092] In one embodiment, the light-emitting device 100 is prepared by the light-emitting device preparation method described above.

[0093] This application also relates to a display device, which includes the light-emitting device provided in this application. The display device can be any electronic product with display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0094] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0095] Example 1

[0096] This embodiment provides a fully light-emitting device and a single-electron device. It can be understood that a fully light-emitting device is a light-emitting device having both a hole functional layer and an electron functional layer, while a single-electron device is a light-emitting device without a hole functional layer.

[0097] The fabrication of the all-light-emitting device includes the following steps:

[0098] Step 1: Place the ITO glass substrate in a glass dish containing an ethanol solution, and ultrasonically clean it for 20 minutes each with acetone, deionized water, and ethanol in sequence, then dry it with a nitrogen gun; then place the cleaned ITO glass substrate in oxygen plasma for 10 minutes and treat the surface of the ITO glass substrate with ultraviolet-ozone for 15 minutes.

[0099] Step 2: Spin-coat PEDOT:PSS onto the cleaned ITO glass substrate in air at a speed of 3500 r / min for 30 seconds; after spin-coating, place it in air for annealing at a temperature of 150℃ for 30 minutes; after annealing, quickly transfer the substrate to a glove box in a nitrogen atmosphere to obtain a hole injection layer with a thickness of 20 nm.

[0100] Step 3: Spin-coat a TFB-chlorobenzene solution with a concentration of 8 mg / mL onto the hole injection layer. The spin-coating speed is 3500 r / min and the time is 30 seconds. After spin-coating, place it in air for annealing at a temperature of 150℃ for 30 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0101] Step 4: Spin-coat the quantum dot solution onto the hole transport layer at a spin speed of 2000 rpm for 30 seconds. After spin-coating, anneal the layer at 60 degrees Celsius in a glove box for 5 minutes to obtain a luminescent layer with a thickness of 25 nm. The structure of the blue quantum dots used is: CdZnSe / 2ZnSe / 0.05Cd / Cd0.6ZnS2.

[0102] Step 5: Spin-coat a ZnO-ethanol solution (concentration of 30 mg / mL) onto the luminescent layer at a speed of 3000 r / min for 30 seconds, and anneal to obtain an electron transport layer with a thickness of 30 nm.

[0103] Step 6: In the vacuum chamber, Ag is deposited on the light-emitting layer to obtain a cathode (silver electrode) with a thickness of 100 nm;

[0104] Step 7: Add 100 μL of silver tetrafluoroborate in ether solution (concentration 15 mg / mL) to the surface of the silver electrode, let it stand for 30 seconds, spin-coat it at 3000 r / min and spin dry, and heat it at 80 °C for 30 minutes.

[0105] Step 8: Package the device to obtain a fully light-emitting device.

[0106] Step 9: Immediately power on the fabricated all-light-emitting device and perform a lifetime test.

[0107] The fabrication of the single-electron device is basically the same as that of the all-light-emitting device, except that steps 2 and 3 are omitted, and quantum dot solution is directly spin-coated onto ITO in step 4; finally, the single-electron device (EOD) is obtained through encapsulation. The fabricated single-electron device is immediately powered on for power-on aging test.

[0108] When the all-light-emitting device and the single-electron device are powered on, silver channels are formed in the electron transport layer.

[0109] Example 2

[0110] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 1, except that the resting time in step 7 is 60 seconds.

[0111] Example 3

[0112] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 1, except that the resting time in step 7 is 120s.

[0113] Example 4

[0114] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 1, the only difference being that in step 7, the resting time is 240s.

[0115] Example 5

[0116] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 1, the only difference being that in step 7, the resting time is 90 seconds.

[0117] Example 6

[0118] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 5, except that both the fully light-emitting device and the single-electron device are placed for 2 hours after fabrication before being powered on.

[0119] Example 7

[0120] This embodiment provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this embodiment is basically the same as that in Embodiment 6, except that: both the fully light-emitting device and the single-electron device are placed for 24 hours after fabrication before being powered on.

[0121] Comparative Example 1:

[0122] This comparative example provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this comparative example is basically the same as that in Example 1, except that step 7 is omitted and the device is directly packaged.

[0123] Comparative Example 2:

[0124] This comparative example provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this comparative example is basically the same as that in Example 1, except that step 7 is omitted and the device is directly packaged; and the fully light-emitting device and the single-electron device are placed for 24 hours after fabrication before being powered on.

[0125] Comparative Example 3

[0126] This comparative example provides a fully light-emitting device and a single-electron device. The fabrication of the fully light-emitting device and the single-electron device in this comparative example is basically the same as that in Comparative Example 2, except that both the fully light-emitting device and the single-electron device are placed for 48 hours after fabrication before being powered on.

[0127] Detection Example 1

[0128] This embodiment provides a single-hole device. The fabrication of the single-hole device in this embodiment is basically the same as that in Embodiment 1, except that steps 5, 7, and 9 are omitted, an electron transport layer is not formed, a cathode is directly formed on the light-emitting layer, and the single-hole device (HOD) is obtained by encapsulation.

[0129] Experimental Example 1

[0130] Based on the hole-only device (HOD) of Example 1 and the single-electron device (EOD) of Examples 1-7 and Comparative Examples 1-3, power-on aging tests were performed to obtain the operating voltage-time curve and the current density-voltage curve, as shown in the figure. Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6a and Figure 6b .in, Figure 3a and Figure 3bThe figures show the operating voltage-time curves and current density-voltage curves of the single electronic devices (EODs) in Comparative Examples 1-3, respectively. Figure 4a and Figure 4b The figures show the operating voltage-time curves and current density-voltage curves for the single electronic devices (EODs) in Examples 1-4, respectively. Figure 5a and Figure 5b Figure 5 shows the voltage-time curves and current density-voltage curves for the single-electron device (EOD) in Examples 5-7, respectively; Figure 6 shows the voltage-time curves and current density-voltage curves for the single-hole device (HOD) in Detection Example 1. The current density at the operating voltage (8V) and the operating voltage under steady-state conditions of the single-electron device (EOD) in Examples 1-7 and Comparative Examples 1-3 are detailed in Table 1.

[0131] Experiment Example 2

[0132] The all-light-emitting device in Example 1 was tested using transmission electron microscopy (TEM). See [link to documentation]. Figure 7 , Figure 7 This is a TEM image of the single electronic device in Example 1. Figure 7 In the structure, from bottom to top, there is an ITO glass substrate 101, a light-emitting layer 102, an electron transport layer 103, a silver electrode 104, and a silver channel 105 in the electron transport layer 103. Therefore, the fabrication method of the light-emitting device provided in this application enables the formation of a silver channel 105 in the electron transport layer 103, and the silver channel 105 connects the light-emitting layer 102 and the silver electrode 104.

[0133] Experimental Example 3

[0134] The performance of the all-light-emitting devices in Examples 1-7 and Comparative Examples 1-3 was tested, including external quantum efficiency (EQE), turn-on voltage, and lifetime. The external quantum efficiency (EQE) was measured using an EQE optical measuring instrument, and the lifetime was measured at a constant current density (2 mA / cm²). 2 The time it takes for the brightness of a fully emitting device to drop to 95% of its initial brightness (converted to 1000 nits). See Table 1 below for the test results.

[0135] Table 1

[0136]

[0137]

[0138] As shown in Table 1:

[0139] The experimental results above show that the all-light-emitting devices in Examples 1, 2, and 5-7 all exhibit good device lifetimes, possibly due to the reduction in the turn-on voltage and the effective improvement in electron injection (derived from the current density and operating voltage data of the EOD devices at 8V). Specifically, the reduction in the turn-on voltage and the effective improvement in electron injection may be due to the formation of silver channels in the electron transport layer of the all-light-emitting devices, which effectively reduces the energy barrier at the interface between the light-emitting layer and the electron transport layer, facilitating the entry of electrons from the electron transport layer into the light-emitting layer, thereby improving electron injection efficiency and reducing the turn-on voltage of the light-emitting devices.

[0140] Compared to Figure 6a and Figure 6b The current density of the HOD device in Example 1 was 94.68 mA·cm⁻¹. -2 The operating voltage (4.5V) and the all-light-emitting devices of Examples 1, 2 and 5-7 may have silver channels formed in their electron transport layer, which can effectively reduce the energy barrier at the interface between the light-emitting layer and the electron transport layer, which is conducive to electrons entering the light-emitting layer from the electron transport layer, thereby resulting in a more balanced carrier injection.

[0141] Compared to the HOD device in Example 1, the carrier injection of the all-light-emitting devices in Examples 3 and 4 was more unbalanced and the lifetime was reduced. This may be due to the active reagent staying for too long, resulting in a large amount of Ag injection and an excess of electron injection in the all-light-emitting device.

[0142] As can be seen from the voltage-time curves of the EOD devices in Examples 1-7 and Comparative Examples 1-3, the EOD devices in Examples 1-7 have a rapid voltage drop phase in the initial stage, which is the formation stage of Ag atom channels. This leads to a reduction in operating voltage, which improves the electron injection of the all-light-emitting device and thus greatly improves the luminous efficiency and lifetime of the all-light-emitting device.

[0143] As can be seen from Examples 5-7, the all-light-emitting device of this application can significantly shorten the forward aging time. The test results in Examples 6 and 7 are similar, indicating that the optimal forward aging effect can be achieved within 2 hours after the EOD device and other light-emitting devices are prepared. In contrast, in Comparative Examples 1-3, without the activation reagent treatment, the forward aging time of the light-emitting device is more than 24 hours to achieve the optimal effect. This indicates that the formation of silver channels in the electron transport layer through the activation reagent treatment can effectively promote the interaction between the cathode and the electron transport layer, shortening the forward aging time of the light-emitting device.

[0144] Compared to the all-light-emitting devices in Examples 1-3, both the external quantum efficiency (EQE) and lifetime are relatively low. This may be due to insufficient electron injection, leading to an imbalance between electron and hole injection in the device, resulting in poor luminous efficiency and a low EQE. The imbalance between electron and hole injection also leads to an excessive number of holes in the light-emitting layer and the device itself, causing damage to the light-emitting layer and other functional layers, thus affecting the device's lifetime.

[0145] The experimental data above show that activating agent treatment for an appropriate time can effectively improve electron injection in light-emitting devices, thereby reducing the turn-on voltage and extending the device's lifespan. Simultaneously, activating agent treatment can significantly reduce the device's forward aging time, thus shortening time costs.

[0146] The light-emitting device, its preparation method, and display device provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for fabricating a light-emitting device, characterized in that, include: A prefabricated device is provided, the prefabricated device comprising an anode, a light-emitting layer, a first electron transport layer, and a cathode; A first material is disposed on the surface of the cathode on the side away from the first electron transport layer. The first material is selected from at least one of silver tetrafluoroborate, silver pentafluoropropionate, silver heptafluorobutyrate, silver hexafluorophosphate, and silver acrylate. The prefabricated device is energized to form at least one silver channel in the first electron transport layer, thereby obtaining a light-emitting device containing a second electron transport layer. In this embodiment, the material of the first electron transport layer is an electron transport material; in the second electron transport layer, the silver channel extends from the cathode to the light-emitting layer, the silver channel connects the cathode and the light-emitting layer, and the material of the silver channel includes a mixture of silver and the electron transport material.

2. The preparation method according to claim 1, characterized in that, The cathode is a silver electrode; and / or The cathode has a thickness of 80-120 nm; and / or The electron transport layer has a thickness of 20-40 nm; and / or The mass ratio of the first substance to the area of ​​the cathode is 75~500 μg / cm². 2 .

3. The preparation method according to claim 2, characterized in that, The mass ratio of silver in the second electron transport layer is 1.5 to 4%.

4. The preparation method according to claim 1, characterized in that, The provision of a first material on the surface of the cathode on the side away from the first electron transport layer includes: A first substance solution is applied to the surface of the cathode on the side away from the first electron transport layer using a solution method, and then dried.

5. The preparation method according to claim 4, characterized in that, The solvent of the first substance solution is selected from at least one of diethyl ether, benzene, toluene, and nitromethane; and / or The concentration of the first substance in the first substance solution ranges from 5 to 20 mg / mL; and / or The drying temperature is 60-100℃, and the time is 10-30 min; and / or Before drying, the process also includes: standing for 30-240 seconds.

6. The preparation method according to claim 1, characterized in that, Before energizing the prefabricated device, the method further includes: encapsulating the prefabricated device; and / or The voltage applied is 5-12 V.

7. The preparation method according to claim 2, characterized in that, The electron transport material is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials; the inorganic nanocrystalline material is selected from one or more of zinc oxide, titanium dioxide, tin dioxide, aluminum oxide, calcium oxide, silicon dioxide, gallium oxide, zirconium oxide, nickel oxide, and zirconium trioxide; the doped inorganic nanocrystalline material includes the inorganic nanocrystalline material and a doping element, wherein the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, and Mn; and / or The material of the light-emitting layer is selected from quantum dot materials. The quantum dot materials are selected from at least one of the following: single-structure quantum dots, core-shell structure quantum dots, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots. The single-structure quantum dots are selected from at least one of group II-VI compounds, group III-V compounds, group II-V compounds, group III-VI compounds, group IV-VI compounds, group I-III-VI compounds, group II-IV-VI compounds, and group IV elements. The group II-VI compounds are selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdTeS, Cd... At least one of ZnSeS, CdZnSeTe, and CdZnSTe, wherein the III-V group compound is selected from at least one of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP, and InAlNP, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot is selected from any one of the single-structure quantum dots, and the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, and ZnS; the general structural formula of the inorganic perovskite quantum dot is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite quantum dot is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH 3+ Or NH3(CH2) n NH3 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them; and / or The anode is selected from one or more of a metal electrode, a carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene, and carbon fibers; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; the composite electrode is selected from at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The prefabricated device further includes a hole functional layer disposed between the anode and the light-emitting layer. The hole functional layer includes a hole injection layer and / or a hole transport layer. When the hole functional layer includes both the hole injection layer and the hole transport layer, the hole injection layer is disposed closer to the anode, and the hole transport layer is disposed closer to the light-emitting layer. The material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) and polyethylene glycol. Carbazole, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine), 4,4',4''-tris(carbazole-9-yl)triphenylamine, 4,4'-di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl The material of the hole injection layer is selected from one or more of the following: phenyl-4,4'-diamine, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid), Spiro-NPB, Spiro-TPD, doped or undoped NiO, MoO3, WO3, V2O5, p-type gallium nitride, CrO3, CuO, MoS2, MoSe2, WS3, WSe3, CuS, and CuSCN; The following are selected from the following: 6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, copper phthalocyanine, transition metal oxides, and transition metal chalcogenides; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO; and the metal chalcogenides include one or more of MoS2, MoSe2, WS3, WSe3, and CuS.

8. A light-emitting device, comprising a stacked anode, a light-emitting layer, an electron transport layer, and a cathode, characterized in that, The electron transport layer includes at least one silver channel extending from the cathode to the light-emitting layer, and one or more of the at least one silver channel connect the cathode and the light-emitting layer; the material of the electron transport layer is an electron transport material, and the material of the silver channel is a mixture of silver and the electron transport material.

9. The light-emitting device as described in claim 8, characterized in that, The contact area between each silver channel and the cathode is 1~9 nm. 2 ; and / or The mass ratio of silver in the electron transport layer is 1.5 to 4%.

10. The light-emitting device as described in claim 8, characterized in that, The cathode is a silver electrode; and / or The cathode has a thickness of 80-120 nm; and / or The electron transport material is selected from inorganic nanocrystalline materials or doped inorganic nanocrystalline materials; the inorganic nanocrystalline material is selected from one or more of zinc oxide, titanium dioxide, tin dioxide, aluminum oxide, calcium oxide, silicon dioxide, gallium oxide, zirconium oxide, nickel oxide, and zirconium trioxide; the doped inorganic nanocrystalline material includes the inorganic nanocrystalline material and a doping element, wherein the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, and Mn; and / or The electron transport layer has a thickness of 20-40 nm; and / or The material of the light-emitting layer is selected from quantum dot materials. The quantum dot materials are selected from at least one of the following: single-structure quantum dots, core-shell structure quantum dots, doped or undoped inorganic perovskite quantum dots, or organic-inorganic hybrid perovskite quantum dots. The single-structure quantum dots are selected from at least one of group II-VI compounds, group III-V compounds, group II-V compounds, group III-VI compounds, group IV-VI compounds, group I-III-VI compounds, group II-IV-VI compounds, and group IV elements. The group II-VI compounds are selected from CdSe, CdS, CdTe, ZnSe, ZnS, CdTe, ZnTe, CdZnS, CdZnSe, CdZnTe, ZnSeS, ZnSeTe, ZnTeS, CdSeS, CdSeTe, CdTeS, CdTeS, Cd... At least one of ZnSeS, CdZnSeTe, and CdZnSTe, wherein the III-V group compound is selected from at least one of InP, InAs, GaP, GaAs, GaSb, AlN, AlP, InAsP, InNP, InNSb, GaAlNP, and InAlNP, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot is selected from any one of the single-structure quantum dots, and the shell material of the core-shell quantum dot is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, and ZnS; the general structural formula of the inorganic perovskite quantum dot is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite quantum dot is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH 3+ Or NH3(CH2) n NH3 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them; and / or The anode is selected from one or more of a metal electrode, a carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene, and carbon fibers; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO; the composite electrode is selected from at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The light-emitting device further includes a hole functional layer; the hole functional layer includes a hole injection layer and / or a hole transport layer; when the hole functional layer includes the hole injection layer and the hole transport layer, the hole injection layer is disposed near the anode, and the hole transport layer is disposed near the light-emitting layer; wherein, the material of the hole transport layer is selected from poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine), polyvinylcarbazole, poly(N,N'-bis(4-butyl)... 4,4',4'-tris(carbazole-9-yl)triphenylamine, 4,4'-di(9-carbazole)biphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, poly(N ... (3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid), Spiro-NPB, Spiro-TPD, doped or undoped NiO, MoO3, WO3, V2O5, p-type gallium nitride, CrO3, CuO, MoS2, MoSe2, WS3, WSe3, CuS, CuSCN; the hole injection layer material is selected from one or more of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, copper phthalocyanine, transition metal oxides, transition metal chalcogenides; wherein the transition metal oxide includes one or more of NiO, MoO2, WO3, CuO; the metal chalcogenide includes one or more of MoS2, MoSe2, WS3, WSe3, CuS.

11. A display device, characterized in that, The display device comprises a light-emitting device prepared by the method for preparing a light-emitting device according to any one of claims 1-7; or the display device comprises a light-emitting device according to any one of claims 8-10.

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