Thin film and preparation method thereof, light-emitting device and display device

Abstract

The invention discloses a thin film and a preparation method thereof, a light-emitting device and a display device. The thin film comprises a porous base film, the material of the porous base film comprises first nano particles, the porous base film is provided with holes, the thin film further comprises second nano particles, and the second nano particles are located in the holes. When the thin film is used in the light-emitting device, the service life of the light-emitting device can be prolonged.

Description

Technical Field

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

[0002] Inorganic nanoparticles possess excellent optoelectronic properties, such as high mobility, strong photoconductivity, adjustable bandgap based on particle size, and strong material absorption, and are therefore often used in functional thin films.

[0003] However, the carrier mobility of existing functional films prepared from inorganic nanoparticles cannot be effectively controlled. Summary of the Invention

[0004] In view of this, this application provides a thin film, a method for preparing the same, a light-emitting device, and a display device.

[0005] The embodiments of this application are implemented as follows: a thin film includes a porous base film, the material of the porous base film includes first nanoparticles, the porous base film has pores, and the thin film also includes second nanoparticles, the second nanoparticles being located in the pores of the porous base film.

[0006] Optionally, in some embodiments of this application, the porosity of the thin film is 8-14%; and / or

[0007] The porosity of the porous base membrane is 25-60%; and / or

[0008] The second nanoparticles adhere to the pore walls of the porous substrate membrane; and / or

[0009] The average particle size of the first nanoparticle is 2–20 nm; and / or

[0010] The average pore size of the porous base membrane is 2–20 nm.

[0011] Optionally, in some embodiments of this application, the first nanoparticle is a doped first nanoparticle or an undoped first nanoparticle, wherein the doped first nanoparticle is doped with a first element; and / or

[0012] The second nanoparticle contains the first element.

[0013] Optionally, in some embodiments of this application, the molar content of the first element in the film is less than or equal to 50%.

[0014] Optionally, in some embodiments of this application, the first nanoparticle is an N-type inorganic nanoparticle, which includes one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. The first metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The group IIB-VIA inorganic particles include one or more of ZnS, ZnSe, and CdS. The group IIIA-VA inorganic particles include one or more of InP and GaP. The group IB-IIIA-VIA inorganic particles include one or more of CuInS and CuGaS. and / or

[0015] The first element includes one or more of Al, Ag, In, W, Mo, Sn, V, Fe, Mg, Co, B, Ca, Cu, Zn, and F; and / or

[0016] The material of the second nanoparticle includes one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide.

[0017] Optionally, in some embodiments of this application, the first nanoparticle is a p-type inorganic nanoparticle, wherein...

[0018] The p-type inorganic nanoparticles comprise one or more of a second metal oxide particle, a metal sulfide, and a metal nitride. The second metal oxide particle is made of one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfide comprises one or more of CuS, MoS3, and WS3. The metal nitride comprises p-type gallium nitride. and / or

[0019] The first element includes one or more of Li, Mg, Al, K, Ca, Co, S, P, Cl, N, Si, As, F, and Cu; and / or

[0020] The material of the second nanoparticle includes one or more of lithium oxide, magnesium oxide, aluminum oxide, potassium oxide, calcium oxide, cobalt oxide, phosphorus oxide, silicon oxide, arsenic oxide, and copper oxide.

[0021] Optionally, in some embodiments of this application, the first nanoparticle is either the doped first nanoparticle or the undoped first nanoparticle, and the doped first nanoparticle is further doped with a second element; and / or

[0022] The film also includes a third nanoparticle located in the pores of the porous base film, and the cation in the third nanoparticle contains a second element.

[0023] Optionally, in some embodiments of this application, the third nanoparticle is attached to the pore walls of the porous substrate membrane; and / or

[0024] The second element includes one or more of Ag, Al, Ni, Pt, Au, Ir, Cu, Mo, Ca, Mg, Ba, In, and Sn; and / or

[0025] The material of the third nanoparticle includes one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide; and / or

[0026] In the thin film, the molar content of the second element is less than or equal to 30%.

[0027] Accordingly, embodiments of this application also provide a method for preparing a thin film, comprising the following steps:

[0028] A dispersion is provided, the dispersion comprising first nanoparticles, organic nanoparticles and a first solvent; the dispersion is placed on a substrate and dried to obtain a pre-formed film.

[0029] The organic nanoparticles in the pre-formed membrane are vaporized to obtain a porous base membrane; and

[0030] The porous substrate is subjected to a first doping treatment with a first element to obtain the thin film.

[0031] Optionally, in some embodiments of this application, the organic nanoparticles include one or more of the following: carbon quantum dots, oligobenzopyran quantum dots, oligobenzothiophene quantum dots, oligothiophene quantum dots, oligopyrrole quantum dots, oligostyrene quantum dots, polystyrene quantum dots, oligo-p-phenylene quantum dots, poly(3-hexylthiophene) quantum dots, poly(p-phenylene-2,7-divinylbenzene) quantum dots, and poly(benzopyrrole vinyl oxide) quantum dots; and / or

[0032] The organic nanoparticles have an average particle size of 4–20 nm; and / or

[0033] The mass ratio of the organic nanoparticles to the first nanoparticles is (0.05–0.5):1; and / or

[0034] In the dispersion, the mass concentration of the first nanoparticles is 5–50 mg / mL; and / or

[0035] The first solvent includes one or more of alcohol solvents and ether solvents, wherein the alcohol solvent includes one or more of ethanol, isopropanol, butanol, n-pentanol, and isoamyl alcohol, and the ether solvent includes ethylene glycol monomethyl ether; and / or

[0036] The porosity of the porous base membrane is 25-60%;

[0037] The porosity of the film is 8-14%;

[0038] The average pore size of the porous base membrane is 2–20 nm.

[0039] Optionally, in some embodiments of this application, the gasification treatment includes oxygen ion treatment, which includes one or more of oxygen ion irradiation and oxygen plasma treatment. Optionally, the dose of the high-energy oxygen ion treatment is 1×10⁻⁶. 12 ~1×10 20 ions / cm 2 The time is 2–30 minutes; and / or

[0040] The gasification treatment includes one or more of high-temperature ozone treatment and high-temperature peroxide gas treatment. Optionally, the temperature of the high-temperature ozone treatment and high-temperature peroxide gas treatment is 100-150°C.

[0041] Optionally, in some embodiments of this application, the first doping process includes one or more of ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering; and / or

[0042] The dose of the first doping treatment is 1×10 12 ~1×10 20 ions / cm 2 The time is 5 to 30 minutes.

[0043] Optionally, in some embodiments of this application, after performing a first doping treatment on the porous base film with a first element and before obtaining the thin film, the method further includes performing a second doping treatment on the porous base film with a second element.

[0044] Optionally, the second doping process includes one or more of the following: ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering; and / or

[0045] Optionally, the dose of the second doping treatment is 1×10⁻⁶. 12 ~1×10 20 ions / cm 2 The time is 5 to 30 minutes; and / or

[0046] The ratio of the time for the first doping treatment to the time for the second doping treatment is 1:(0.05~0.5).

[0047] Accordingly, this application also provides a light-emitting device, including an anode, a light-emitting layer, and a cathode stacked sequentially, and further including an electronic functional layer located between the light-emitting layer and the cathode and / or a hole functional layer located between the anode and the light-emitting layer, wherein,

[0048] The electronic functional layer is the thin film, or the electronic functional layer is a thin film prepared by the preparation method; and / or,

[0049] The hole-functional layer is the thin film, or the hole-functional layer is the thin film prepared by the preparation method.

[0050] Optionally, in some embodiments of this application, the electronic functional layer further includes the second element, and the type of the second element is the same as the type of metal in the cathode; and / or

[0051] The hole functional layer further includes the second element, and the type of the second element is the same as the type of metal in the anode; and / or

[0052] The light-emitting device further includes a first buffer layer located between the light-emitting layer and the electronic functional layer, wherein the material of the first buffer layer comprises N-type inorganic particles; and / or

[0053] The light-emitting device also includes a second buffer layer located between the hole-functional layer and the light-emitting layer, and the material of the second buffer layer includes P-type inorganic particles.

[0054] Optionally, in some embodiments of this application, the N-type inorganic particles include one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. The first metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The group IIB-VIA inorganic particles include one or more of ZnS, ZnSe, and CdS. The group IIIA-VA inorganic particles include one or more of InP and GaP. The group IB-IIIA-VIA inorganic particles include one or more of CuInS and CuGaS; and / or

[0055] The P-type inorganic particles include one or more of a second metal oxide particle, a metal sulfide, and a metal nitride. The material of the second metal oxide particle includes one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfide includes one or more of CuS, MoS3, and WS3. The metal nitride includes P-type gallium nitride; and / or

[0056] The thickness of the first buffer layer is 5–20 nm; and / or

[0057] The thickness of the second buffer layer is 5–20 nm.

[0058] Optionally, in some embodiments of this application, the N-type inorganic particles further include a third element, which includes one or more of Al, Ag, In, W, Mo, Sn, V, Fe, Mg, Co, B, Ca, Cu, Zn, and F; and / or

[0059] The P-type inorganic particles also include a fourth element, which includes one or more of Li, Mg, Al, K, Ca, Co, S, P, Cl, N, Si, As, F, and Cu.

[0060] Optionally, in some embodiments of this application, the anode and the cathode each independently include a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode, or an alloy electrode. The material of the doped metal oxide electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, etc. ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, or BaF2 / Ca / Al, wherein the material of the elemental metal electrode includes one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba, and the alloy electrode includes an Au:Mg alloy electrode or an Ag:Mg alloy electrode; and / or

[0061] The material of the light-emitting layer includes one or more of organic light-emitting materials and quantum dot light-emitting materials. The organic light-emitting materials include one or more of the following: 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridinium(III), 4,4',4”-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridinium, diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, thermally activated delayed materials, polymers containing BN covalent bonds, hybrid local charge transfer excited state materials, excitopolymer light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives.The quantum dot luminescent material comprises one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite-type inorganic particles. The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots are each independently selected from one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, and ZnS. Te, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the IV-VI group compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, and the III-V compound includes one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and GaAl The perovskite inorganic particles are selected from one or more of NAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, and the I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2; the perovskite inorganic particles include doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors, and the general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + Ions, where M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of them.

[0062] Accordingly, embodiments of this application also provide a display device, including the light-emitting device.

[0063] The carrier mobility of the thin film described in this application can be effectively and precisely controlled, which is beneficial to improving the lifespan of the light-emitting device when the thin film is used in the light-emitting device. Attached Figure Description

[0064] 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.

[0065] Figure 1 This is a flowchart of a thin film preparation method provided in an embodiment of this application;

[0066] Figure 2 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this application;

[0067] Figure 3 This is a schematic diagram of another light-emitting device provided in an embodiment of this application;

[0068] Figure 4 This is a schematic diagram of another light-emitting device provided in an embodiment of this application;

[0069] Figure 5 This is a schematic diagram of another light-emitting device provided in an embodiment of this application;

[0070] Figure 6 This is a schematic diagram of another light-emitting device provided in an embodiment of this application;

[0071] Figure 7 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this application;

[0072] Figure 8 This is a flowchart illustrating another method for fabricating a light-emitting device provided in this application embodiment;

[0073] Figure 9 These are current density-voltage curves of the light-emitting devices in Device Embodiments 1, 11, 12 and Device Comparative Example 1 of this application;

[0074] Figure 10 These are current efficiency-luminance curves of the light-emitting devices in Device Embodiments 1, 11, 12 and Device Comparative Example 1 of this application.

[0075] Figure label:

[0076] Light-emitting device 100; anode 10; light-emitting layer 20; cathode 30; electron functional layer 40; hole functional layer 50; first buffer layer 60; second buffer layer 70. Detailed Implementation

[0077] 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.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0079] 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 operating state, specifically the drawing directions 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". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0080] 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.

[0081] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "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.

[0082] In this application, the term "on" forming another layer on a certain layer is a broad concept. It can mean that the formed other layer is adjacent to a certain layer, or it can mean that there are other spacer structures between the other layer and the certain layer. For example, when a second electrode is formed "on" a first charge carrier functional layer, the term "on" can mean that the formed second electrode is adjacent to the first charge carrier functional layer, or it can mean that there are other spacer structures between the second electrode and the first charge carrier functional layer, such as a light-emitting layer.

[0083] 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, whichever applies. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0084] Inorganic nanoparticles, such as metal oxides, are often used as the carrier functional layer in light-emitting devices. Inorganic nanoparticles have attracted much attention due to their energy level structure, which is well-matched to light-emitting quantum dots, ease of design and control in material synthesis, and high carrier transport properties. However, single inorganic nanoparticles cannot meet the requirements of high-performance devices. Therefore, solution-based metal doping is often used to improve the performance of inorganic nanoparticles. However, the metal doping amount obtained by solution synthesis is usually low, and further increasing the metal content often leads to instability of the colloid. On the other hand, when performing multi-element doping, solution synthesis often results in a complex and difficult-to-control synthesis system, making it impossible to effectively and precisely obtain the desired material.

[0085] The technical solution of this application is as follows:

[0086] In a first aspect, embodiments of this application provide a thin film, the thin film comprising a porous base film, the material of the porous base film comprising first nanoparticles, the porous base film having pores, and the thin film further comprising second nanoparticles, the second nanoparticles being located in the pores of the porous base film.

[0087] In some embodiments, the porosity of the film is 8-14%, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc.

[0088] In some embodiments, the porosity of the porous base membrane is 25% to 60%, for example, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc.

[0089] It should be noted that the porosity in this application refers to the proportion of the volume of pores in the film to the total volume.

[0090] It should be noted that the porosity test method for the thin film or porous base film in this application is the BET method, that is, the Brunauer-Emmett-Teller (BET) law is used to calculate the porosity of the material. Specifically, the thin film sample is pretreated at 100-140℃ (not higher than the processing temperature when the thin film is prepared for the device) and 10Pa for 10min to remove the originally adsorbed gas molecules; then the adsorption-desorption test is performed in the range of 0.01-500kPa, and the test system directly reads the required data.

[0091] It should be noted that the porosity test of the porous base membrane in this application is performed after the porous base membrane is prepared and before the thin film is prepared using the porous base membrane.

[0092] In some embodiments, the second nanoparticles are attached to the pore walls of the porous substrate membrane.

[0093] In some embodiments, the average particle size of the first nanoparticle is 2 to 20 nm, for example, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0094] In some embodiments, the first nanoparticle is a doped first nanoparticle or an undoped first nanoparticle, wherein the doped first nanoparticle is doped with a first element.

[0095] In some embodiments, the second nanoparticle contains the first element.

[0096] Because of the defects on the surface of the first nanoparticle, it is easier for the first nanoparticle to form bonds with the first element, thereby achieving doping of the first nanoparticle, which improves the stability and carrier transport properties of the first nanoparticle, and can also achieve energy level control of the thin film. For example, doping ZnO with Mg can increase the band gap of the film.

[0097] The thin film described in this application includes the first nanoparticle and the second nanoparticle, wherein the second nanoparticle contains the first element, so that the thin film has a high doping concentration, which can more effectively control the carrier mobility of the thin film, such as more effectively reducing or increasing the carrier mobility.

[0098] In some embodiments, the average pore size of the porous base film is 2 to 20 nm, for example, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0099] In some embodiments, the molar content of the first element in the thin film is less than or equal to 50%, in other words, the doping amount of the first element can be as high as 50%. Within this content range, the stability and carrier transport properties of the first nanoparticles can be effectively improved, and the energy level of the thin film can also be effectively controlled.

[0100] The first nanoparticle can be an N-type inorganic nanoparticle or a P-type inorganic nanoparticle.

[0101] The N-type inorganic nanoparticles include, but are not limited to, one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. The first metal oxide particles are made of one or more of the following: ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The group IIB-VIA inorganic particles include one or more of the following: ZnS, ZnSe, and CdS. The group IIIA-VA inorganic particles include one or more of the following: InP and GaP. The group IB-IIIA-VIA inorganic particles include one or more of the following: CuInS and CuGaS.

[0102] When the first nanoparticle is an N-type inorganic nanoparticle, the first element includes, but is not limited to, one or more of aluminum (Al), silver (Ag), indium (In), tungsten (W), molybdenum (Mo), tin (Sn), vanadium (V), iron (Fe), magnesium (Mg), cobalt (Co), boron (B), calcium (Ca), copper (Cu), zinc (Zn), and fluorine (F). When the first element is one or more of aluminum (Al), silver (Ag), indium (In), tungsten (W), molybdenum (Mo), tin (Sn), vanadium (V), and iron (Fe), the first element can effectively improve the electron transport efficiency of the first nanoparticle. When the first element is one or more of magnesium (Mg), cobalt (Co), boron (B), calcium (Ca), copper (Cu), zinc (Zn), and fluorine (F), the first element can effectively reduce the electron transport efficiency of the first nanoparticle.

[0103] When the first nanoparticle is an N-type inorganic nanoparticle, the material of the second nanoparticle includes, but is not limited to, one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide.

[0104] In some embodiments, the average particle size of the N-type inorganic nanoparticles is 2 to 20 nm, for example, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0105] It is understood that when the first nanoparticle is the N-type inorganic nanoparticle, the thin film can be an electronic functional thin film, such as an electron transport thin film or an electron injection thin film.

[0106] The p-type inorganic nanoparticles include, but are not limited to, one or more of the following: second metal oxide particles, metal sulfides, and metal nitrides. The second metal oxide particles are made of one or more of the following: MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfides include one or more of the following: CuS, MoS3, and WS3. The metal nitrides include p-type gallium nitride.

[0107] When the first nanoparticle is a p-type inorganic nanoparticle, the first element includes one or more of lithium (Li), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), cobalt (Co), sulfur (S), phosphorus (P), chlorine (Cl), nitrogen (N), silicon (Si), arsenic (As), fluorine (F), and copper (Cu). When the first element is one or more of lithium (Li), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), and cobalt (Co), the first element can effectively improve the hole transport efficiency of the first nanoparticle. When the first element is one or more of sulfur (S), phosphorus (P), chlorine (Cl), nitrogen (N), silicon (Si), arsenic (As), fluorine (F), and copper (Cu), the first element can effectively reduce the hole transport efficiency of the first nanoparticle.

[0108] When the first nanoparticle is a p-type inorganic nanoparticle, the material of the second nanoparticle includes, but is not limited to, one or more of lithium oxide, magnesium oxide, aluminum oxide, potassium oxide, calcium oxide, cobalt oxide, phosphorus oxide, silicon oxide, arsenic oxide, and copper oxide.

[0109] In some embodiments, the average particle size of the P-type inorganic nanoparticles is 2 to 20 nm, for example, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0110] It is understood that when the first nanoparticle is the P-type inorganic nanoparticle, the thin film can be a hole-functional thin film, such as a hole transport thin film or a hole injection thin film.

[0111] In some embodiments, the first nanoparticle is either the doped first nanoparticle or the undoped first nanoparticle, wherein the doped first nanoparticle is further doped with a second element; and / or, the thin film further includes a third nanoparticle, wherein the third nanoparticle is located in the pores of the porous base film, and the cation in the third nanoparticle contains the second element.

[0112] In some embodiments, the third nanoparticles are attached to the pore walls of the porous substrate membrane.

[0113] The second element may be one or more of Ag, Al, Ni, Pt, Au, Ir, Cu, Mo, Ca, Mg, Ba, In, and Sn. The second element is a known metallic element used in electrodes. Thus, when the thin film is a charge carrier functional film in contact with the electrode, doping the thin film with the second element can improve the interfacial stability between the charge carrier functional layer and the electrode, reduce the interfacial contact barrier between the charge carrier functional layer and the electrode, and promote the interfacial reaction between the charge carrier functional layer and the electrode.

[0114] The materials of the third nanoparticles include, but are not limited to, one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide.

[0115] In some embodiments, the molar content of the second element in the thin film is less than or equal to 30%. Within this content range, the stability of the carrier functional layer and the electrode can be effectively improved, the interfacial contact barrier can be effectively reduced, and the thin film can also have high conductivity and carrier transport performance.

[0116] Secondly, please refer to Figure 1 This application also provides a method for preparing a thin film, comprising the following steps:

[0117] Step S11: Provide a dispersion liquid, which includes first nanoparticles, organic nanoparticles and a first solvent. Set the dispersion liquid on a substrate and dry it to obtain a pre-formed film.

[0118] Step S12: The organic nanoparticles in the preform are vaporized to convert them into gas and escape from the preform, thereby forming pores in the preform and obtaining a porous base film.

[0119] Step S13: Perform a first doping treatment on the porous base film using a first element to obtain the thin film.

[0120] In step S11:

[0121] The first nanoparticle is as described above and will not be repeated here.

[0122] The organic nanoparticles may be selected from, but are not limited to, one or more of the following: carbon quantum dots, oligobenzopyran (OPV) quantum dots, oligobenzothiophene (OPT) quantum dots, oligothiophene (OT) quantum dots, oligopyrrole (OPy) quantum dots, oligostyrene (OPSt) quantum dots, polystyrene (PPy) quantum dots, oligoparabenzene (OPB) quantum dots, poly(3-hexylthiophene) (P3HT) quantum dots, poly(2,7-diylvinylene) (PPV) quantum dots, and poly(benzopyrrolevinylene oxide) (PBO) quantum dots.

[0123] In some embodiments, the surface of the carbon quantum dots has one or more functional groups such as hydroxyl, carboxyl, amino, thiol, and triphenylphosphine.

[0124] The average particle size of the organic nanoparticles is 2 to 10 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc.

[0125] The first solvent includes, but is not limited to, one or more of alcohol solvents and ether solvents. The alcohol solvent includes one or more of ethanol, isopropanol, butanol, n-pentanol, and isoamyl alcohol. The ether solvent includes ethylene glycol monomethyl ether.

[0126] In some embodiments, the mass ratio of the organic nanoparticles to the first nanoparticles is (0.05–0.5):1, for example, 0.05:1, 0.08:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, etc. Within this range, it is beneficial to form a porous base film, effectively control the carrier transport capacity, and reserve space for film processing and recrystallization.

[0127] In some embodiments, the mass concentration of the first nanoparticles in the dispersion is 5–50 mg / mL. This range is advantageous for preparing films with good film-forming properties.

[0128] The substrate can be a known substrate for thin film preparation, or a light-emitting device preform for preparing a light-emitting device, such as an anode substrate, or a cathode substrate, or an anode substrate or cathode substrate including a light-emitting layer, or an anode substrate with stacked hole functional layers, or a cathode substrate with stacked electron transport layers and light-emitting layers, etc.

[0129] The drying process can be any known method for drying wet films, such as heat drying, reduced pressure drying, vacuum drying, freeze drying, etc.

[0130] In at least one embodiment, the drying is vacuum drying. Further, the pressure of the vacuum drying is 0.001 to 10 Pa, for example, 0.01 Pa, 0.1 Pa, 1 Pa, 2 Pa, 3 Pa, 4 Pa, 5 Pa, 6 Pa, 7 Pa, 8 Pa, 9 Pa, 10 Pa, etc.

[0131] It is understood that the preformed membrane includes the first nanoparticles and the organic nanoparticles.

[0132] In step S12:

[0133] In some embodiments, the porosity of the porous base membrane is 25-60%.

[0134] The gasification treatment can be a high-energy strong oxidation treatment, which can be one or more of high-energy oxygen ion treatment, high-temperature ozone treatment, and high-temperature peroxide gas treatment.

[0135] The high-energy oxygen ion treatment can be one or more of oxygen ion irradiation and oxygen plasma treatment.

[0136] In some embodiments, the dose of the high-energy oxygen ion treatment is 1 × 10⁻⁶. 12 ~1×10 20 ions / cm 2 For example, 1×10 12 ions / cm 2 1×10 13 ions / cm 2 1×10 14 ions / cm 2 1×10 15 ions / cm 2 1×10 16 ions / cm 2 1×10 17 ions / cm 2 1×10 18 ions / cm 2 1×10 19 ions / cm 2 1×10 20 ions / cm 2 The time is 2 to 30 minutes, for example, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc. Within this range, it is beneficial to form a porous base film.

[0137] The high-temperature ozone treatment and high-temperature peroxide gas treatment are performed at temperatures ranging from 100 to 150°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, and 150°C. Within this temperature range, ozone and / or peroxides can effectively react with organic nanoparticles to generate gas, thereby achieving the gasification treatment of organic nanoparticles and forming a porous base membrane.

[0138] In step S13:

[0139] The first doping treatment can be one or more of the following: ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering.

[0140] The dose of the first doping treatment is 1×10 12 ~1×10 20 ions / cm 2 For example, 1×10 12 ~1×10 20 ions / cm 2 For example, 1×10 12 ions / cm 2 1×10 13 ions / cm 2 1×10 14 ions / cm 2 1×10 15 ions / cm 2 1×10 16 ions / cm 2 1×10 17 ions / cm 2 1×10 18 ions / cm 2 1×10 19 ions / cm 2 1×10 20 ions / cm 2 The time is 5 to 30 minutes, for example, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc. Doping can be effectively performed within this range.

[0141] During the first doping treatment, the first element can be deposited in the pores of the porous base film and react with the oxygen remaining in the pores during the vaporization treatment to generate the second nanoparticle; it can also combine with the surface of the first nanoparticle or enter the interior of the first nanoparticle to perform surface doping and / or internal doping of the first nanoparticle.

[0142] The first element and the second nanoparticle are as described above and will not be repeated here.

[0143] It is understood that when the inorganic nanoparticles are N-type inorganic nanoparticles, the first element includes one or more of aluminum (Al), silver (Ag), indium (In), tungsten (W), molybdenum (Mo), tin (Sn), vanadium (V), iron (Fe), Mg, cobalt (Co), boron (B), calcium (Ca), copper (Cu), zinc (Zn), and fluorine (F).

[0144] It is understood that when the inorganic nanoparticles are P-type inorganic nanoparticles, the first element includes one or more of lithium (Li), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), cobalt (Co), sulfur (S), phosphorus (P), chlorine (Cl), nitrogen (N), silicon (Si), arsenic (As), fluorine (F), and copper (Cu).

[0145] In some embodiments, after performing a first doping treatment on the porous base film with a first element and before obtaining the thin film, the method further includes performing a second doping treatment on the porous base film with a second element.

[0146] During the second doping treatment, the second element can be deposited in the pores of the porous base film and react with the oxygen remaining in the pores during the vaporization treatment to generate the third nanoparticle; it can also combine with the surface of the first nanoparticle or enter the interior of the first nanoparticle to perform surface doping and / or internal doping of the first nanoparticle.

[0147] The second element and the third nanoparticle are as described above and will not be repeated here.

[0148] The second doping treatment can be one or more of the following: ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering.

[0149] When the dose of the second doping treatment is 1×10 12 ~1×10 20 ions / cm 2 For example, 1×10 12 ~1×10 20 ions / cm 2 For example, 1×10 12 ions / cm 2 1×10 13 ions / cm 2 1×10 14 ions / cm 2 1×10 15 ions / cm 2 1×10 16 ions / cm 2 1×10 17ions / cm 2 1×10 18 ions / cm 2 1×10 19 ions / cm 2 1×10 20 ions / cm 2 The time is 2 to 30 minutes, for example, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, etc. Doping can be effectively performed within this range.

[0150] In some embodiments, the ratio of the time of the first doping treatment to the time of the second doping treatment is 1:(0.05~0.5), for example, 1:0.05, 1:0.08, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, etc.

[0151] The thin film preparation method described in this application involves adding organic nanoparticles to a dispersion, forming a film, and then removing the film layer by vaporization, thereby creating pores within the film layer to obtain a porous base film. Compared to a continuous thin film, the carrier mobility of the porous base film is reduced. Furthermore, by injecting / depositing elements into the porous base film, the carrier mobility of the porous base film can be effectively increased or further reduced, thus preparing a thin film with the desired carrier mobility.

[0152] Furthermore, the thin film preparation method described in this application can improve the conductivity of the thin film by further injecting a second element into the porous base film. On the other hand, when the thin film is in contact with the electrode, the second element is set to be the same as the metal of the electrode. In this way, the interfacial stability between the charge carrier functional layer and the electrode can be improved, the interfacial contact barrier between the charge carrier functional layer and the electrode can be reduced, and the interfacial reaction between the charge carrier functional layer and the electrode can be promoted.

[0153] Furthermore, by first forming a porous base film and then doping elements into the porous base film, a high concentration of element doping can be obtained.

[0154] It should be noted that the pores in the porous base film of this application include pores formed by vaporization treatment and gaps known to exist between adjacent first nanoparticles in the porous base film formed by first nanoparticles, that is, gaps between adjacent first nanoparticles in the porous base film formed by directly forming a film by solution method from the dispersion of first nanoparticles.

[0155] Thirdly, please refer to Figures 2-4This application also provides a light-emitting device 100, including an anode 10, a light-emitting layer 20 and a cathode 30 stacked in sequence.

[0156] The light-emitting device 100 further includes an electronic functional layer 40 located between the light-emitting layer 20 and the cathode 30, and / or a hole functional layer 50 located between the anode 10 and the light-emitting layer 20.

[0157] The electronic functional layer 40 is the thin film described above; and / or, the hole functional layer 50 is the thin film described above.

[0158] It is understandable that when the electronic functional layer 40 is the thin film described above, the inorganic nanoparticles are the N-type inorganic nanoparticles.

[0159] Furthermore, in some embodiments, the electronic functional layer 40 further includes the second element, and the type of the second element is the same as the type of metal in the cathode 30. This effectively improves the stability of the electronic functional layer 40 and the cathode 30, and reduces the interfacial contact barrier between them.

[0160] It is understandable that when the hole functional layer 50 is the thin film described above, the inorganic nanoparticles are the P-type inorganic nanoparticles.

[0161] Furthermore, in some embodiments, the hole functional layer 50 further includes the second element, and the type of the second element is the same as the type of metal in the anode 10. This effectively improves the stability of the hole functional layer 50 and the anode 10, and reduces the interfacial contact barrier between them.

[0162] Please see Figure 5 In some embodiments, the light-emitting device 100 further includes a first buffer layer 60 located between the light-emitting layer 20 and the electronic functional layer 40, the material of the first buffer layer 60 comprising N-type inorganic particles.

[0163] The N-type inorganic particles include, but are not limited to, one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. The first metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The group IIB-VIA inorganic particles include one or more of ZnS, ZnSe, and CdS. The group IIIA-VA inorganic particles include one or more of InP and GaP. The group IB-IIIA-VIA inorganic particles include one or more of CuInS and CuGaS.

[0164] In some embodiments, the N-type inorganic particles may further include a third element, which may include, but is not limited to, one or more of aluminum (Al), silver (Ag), indium (In), tungsten (W), molybdenum (Mo), tin (Sn), vanadium (V), iron (Fe), Mg, cobalt (Co), boron (B), calcium (Ca), copper (Cu), zinc (Zn), and fluorine (F).

[0165] In some embodiments, the thickness of the first buffer layer 60 is 5 to 20 nm, for example, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0166] Please see Figure 6 In some embodiments, the light-emitting device 100 further includes a second buffer layer 70 located between the hole functional layer 50 and the light-emitting layer 20, the material of the second buffer layer 70 comprising P-type inorganic particles.

[0167] The P-type inorganic particles include, but are not limited to, one or more of the following: second metal oxide particles, metal sulfides, and metal nitrides. The second metal oxide particles are made of one or more of the following: MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfides include one or more of the following: CuS, MoS3, and WS3. The metal nitrides include P-type gallium nitride.

[0168] In some embodiments, the P-type inorganic particles may further include a fourth element, which may include, but is not limited to, one or more of lithium (Li), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), cobalt (Co), sulfur (S), phosphorus (P), chlorine (Cl), nitrogen (N), silicon (Si), arsenic (As), fluorine (F), and copper (Cu).

[0169] In some embodiments, the thickness of the second buffer layer 70 is 5 to 20 nm, for example, 5 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc.

[0170] It is understood that the electronic functional layer 40 can be an electron transport layer, an electron injection layer, or a stacked structure formed by an electron transport layer and an electron injection layer.

[0171] It is understood that the hole functional layer 50 can be a hole transport layer, a hole injection layer, or a stacked structure formed by a hole transport layer and a hole injection layer.

[0172] It is understood that when the electronic functional layer 40 in the light-emitting device 100 is not the thin film described above, the electronic functional layer 40 can be any electronic functional layer known in the art, and its material can be either the N-type inorganic nanoparticles described above or an organic electron transport material. It is understood that the N-type inorganic nanoparticles can be doped with the first element and / or the second element described above. The organic electron transport materials include, but are not limited to, NET-164 (manufactured by Novaled), NDN-87 (manufactured by Novaled), NDN-45 (manufactured by Novaled), NDN-18 (manufactured by Novaled), NDN-218 (manufactured by Novaled), and ET093 (manufactured by Idemitsu). The following are listed: (manufactured by Kosan), ETM020 (manufactured by Merck), ETM033 (manufactured by Merck), ETM034 (manufactured by Merck), ETM036 (manufactured by Merck), 4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine, 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, 4,7-diphenyl-1,10-phenanthroline, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 8-hydroxyquinoline aluminum, 8-hydroxyquinoline lithium, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, 8-hydroxyquinoline aluminum Alq3, and one or more of the following ion-conjugated polyelectrolytes.

[0173] It is understood that when the hole functional layer 50 in the light-emitting device 100 is not the thin film described above, but a hole transport layer, the hole transport layer can be a hole transport layer known in the art, and its material can be the p-type inorganic nanoparticles or organic hole transport materials described above. It is understood that the p-type inorganic nanoparticles may also be doped with the first element and / or the second element described above. The organic hole transport material can be selected from, but is not limited to, HTM014 (manufactured by Merck), HTM081 (manufactured by Merck), HTM163 (manufactured by Merck), HTM222 (manufactured by Merck), NHT-5 (manufactured by Novaled), NHT-18 (manufactured by Novaled), NHT-49 (manufactured by Novaled), NHT-51 (manufactured by Novaled), EL-301 (manufactured by Hodogaya), EL-22T (manufactured by Hodogaya), 4,4' -N,N'-Dicarbazolyl-Biphenyl (CBP), Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-Diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine (α-NPD), N,N'-Diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), Poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)biphenylamine) (Poly-TPD), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)spiro(spiro-TP) D), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1' -Biphenyl-4-4'-diamine (NPB), spiroNPB, poly(phenylenevinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MOMO-PPV), 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-omeTAD), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), 1,3-Di(carbazole-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-)phenylenevinylene, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazole)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylates and their derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO, or one or more of these.

[0174] It is understood that when the hole functional layer 50 in the light-emitting device 100 is not the thin film described above, but a hole injection layer, the hole injection layer can be a hole injection layer known in the art, and its material can be the p-type inorganic nanoparticles or organic hole injection materials described above. It is understood that the p-type inorganic nanoparticles may also be doped with the first element and / or the second element described above. The organic hole injection material can be selected from, but is not limited to, NDP-2 (manufactured by Novaled), NDP-9 (manufactured by Novaled), NHT-51 (manufactured by Novaled), F4-TCNQ, F6-TCNNQ, tetrafluorotetracyanoquinone dimethyl ether, 7,7,8,8-tetracyano-p-benzodiquinone dimethyl ether, 4,4',4”-tris(2-naphthylphenylamino)triphenylamine (m-MTDATA), perylenetetracarboxylic acid. One or more of the following: dianhydride, pentaphenyl, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HAT-CN), PEDOT, PEDOT:PSS, PEDOT:PSS derivatives doped with s-MoO3 (PEDOT:PSS:s-MoO3), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, and tetracyanoquinone dimethyl ether (F4-TCQN).

[0175] The anode 10 and the cathode 30 are electrodes known in the art for use in light-emitting devices. For example, they can be, independently, but not limited to, doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The material of the doped metal oxide electrode can be, but not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. The composite electrode is an electrode formed by stacking two or more layers of conductive materials, such as 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, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc., where " / " indicates a stacked structure. For example, AZO / Ag / AZO represents a composite electrode comprising sequentially stacked AZO, Ag, and AZO layers. The material of the elemental metal electrode may include, but is not limited to, one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrodes include, but are not limited to, Au:Mg alloy electrodes and Ag:Mg alloy electrodes.

[0176] In some embodiments, the anode 10 is an electrode with a relatively high work function, such as, but not limited to, a doped metal oxide electrode with a relatively high work function, a metal element electrode with a relatively high work function, and a carbon nanotube electrode. The metal element electrode with the high work function can be selected from, but is not limited to, Ni, Pt, Au, Ag, Ir, etc.

[0177] In some embodiments, the cathode 30 is an electrode with a relatively low work function, such as, but not limited to, a metallic elemental electrode, a composite electrode, and an alloy electrode with a relatively low work function. The metallic elemental electrode with a relatively low work function can be Ca, Ba, Al, Mg, etc. The composite electrode with a relatively low work function can be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrode with a relatively low work function can be Au:Mg and Ag:Mg, etc.

[0178] The material of the light-emitting layer 20 may include, but is not limited to, one or more of organic light-emitting materials and quantum dot light-emitting materials.

[0179] The organic light-emitting materials may include, but are not limited to, one or more of the following: CBP:Ir(mppy)3(4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridinium(III)), TCTX:Ir(mmpy)(4,4',4”-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridinium), diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF (thermally activated delayed) materials, polymers containing BN covalent bonds, HLCT (hybrid local charge transfer excited state) materials, Exciplex (excitoplex) light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives.

[0180] The quantum dot luminescent material may include, but is not limited to, one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0181] The materials for the single-structure quantum dots, the core materials for the core-shell structure quantum dots, and the shell materials for the core-shell structure quantum dots may include, but are not limited to, one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The group III-V compounds may include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The group I-III-VI compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0182] As an example, the core-shell structured quantum dots may include, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0183] The perovskite semiconductor material may include, but is not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs. + Ions, where M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of the following. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of them.

[0184] It is understood that the light-emitting device 100 may also be provided with some functional layers that are conventionally used in light-emitting devices and help to improve the performance of the light-emitting device, such as electron blocking layer, hole blocking layer, interface modification layer, etc.

[0185] It is understood that the materials of each layer of the light-emitting device 100 can be adjusted according to the light-emitting requirements of the light-emitting device 100.

[0186] In some embodiments, the light-emitting device 100 further includes a substrate disposed on the side of the anode 10 away from the light-emitting layer 20, or the substrate disposed on the side of the cathode 30 away from the light-emitting layer 20.

[0187] The substrate can be a rigid substrate or a flexible substrate. In some embodiments, the substrate material may include, but is not limited to, one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0188] It is understood that the light-emitting device 100 can be a normally positioned light-emitting device or an inverted light-emitting device. The light-emitting device 100 can be a quantum dot light-emitting device or an organic light-emitting device.

[0189] In some embodiments, the thickness of the anode 10 is 10–120 nm; the thickness of the cathode 30 is 30–150 nm; the thickness of the hole transport layer is 20–100 nm; the thickness of the electron transport layer is 10–180 nm; and the thickness of the hole injection layer is 20–50 nm.

[0190] Fourthly, please refer to Figures 2-4 and Figure 7 This application also provides a method for fabricating a light-emitting device, comprising the following steps:

[0191] Step S21: Provide a light-emitting device preform, wherein the light-emitting device preform includes an anode 10;

[0192] Step S22: Prepare a light-emitting layer 20 on the light-emitting device preform; and

[0193] Step S23: Prepare a cathode 30 on the light-emitting layer 20.

[0194] In some embodiments, after preparing the light-emitting layer 20 on the light-emitting device preform, the method further includes preparing an electronic functional layer 40 on the light-emitting layer 20 using the thin film preparation method described above.

[0195] In some other embodiments, before fabricating the light-emitting layer 20 on the light-emitting device preform, the method further includes: fabricating a hole-functional layer 50 on the light-emitting device preform using the thin film fabrication method described above.

[0196] In some other embodiments, after the light-emitting layer 20 is prepared on the light-emitting device preform, the method further includes: preparing an electronic functional layer 40 on the light-emitting layer 20 using the thin film preparation method described above; and before the light-emitting layer 20 is prepared on the light-emitting device preform, the method further includes: preparing a hole functional layer 50 on the light-emitting device preform using the thin film preparation method described above.

[0197] Please see Figure 5 In some embodiments, before fabricating the electronic functional layer 40 on the light-emitting layer 20, the method further includes: providing N-type inorganic particles and setting the N-type inorganic particles on the light-emitting layer 20 to obtain a first buffer layer 60.

[0198] Understandably, the electronic functional layer 40 is formed on the first buffer layer 60.

[0199] Thus, by first preparing the first buffer layer 60 on the light-emitting layer 20, and then preparing the electronic functional layer 40 on the first buffer layer 60, the damage to the light-emitting layer 20 caused by the vaporization or doping process during the preparation of the electronic functional layer 40 can be avoided.

[0200] Please see Figures 2-4 and Figure 8 This application also provides another method for fabricating a light-emitting device, comprising the following steps:

[0201] Step S31: Provide a light-emitting device preform, wherein the light-emitting device preform includes a cathode 30;

[0202] Step S32: Prepare a light-emitting layer 20 on the light-emitting device preform; and

[0203] Step S33: Prepare an anode 10 on the light-emitting layer 20.

[0204] In some embodiments, after preparing the light-emitting layer 20 on the light-emitting device preform, the method further includes preparing a hole-functional layer 50 on the light-emitting layer 20 using the thin film preparation method described above.

[0205] In some other embodiments, before fabricating the light-emitting layer 20 on the light-emitting device preform, the method further includes: fabricating an electronic functional layer 40 on the light-emitting device preform using the thin film fabrication method described above.

[0206] In some other embodiments, after the light-emitting layer 20 is prepared on the light-emitting device preform, the method further includes: preparing a hole functional layer 50 on the light-emitting layer 20 using the thin film preparation method described above; and before the light-emitting layer 20 is prepared on the light-emitting device preform, the method further includes: preparing an electronic functional layer 40 on the light-emitting device preform using the thin film preparation method described above.

[0207] Please see Figure 8 In some embodiments, the preparation of the hole functional layer 50 on the light-emitting layer 20 further includes: providing P-type inorganic particles and disposing the P-type inorganic particles on the light-emitting layer 20 to obtain a second buffer layer 70.

[0208] Understandably, the hole functional layer 50 is formed on the second buffer layer 70.

[0209] Thus, by first preparing the second buffer layer 70 on the light-emitting layer 20, and then preparing the hole functional layer 50 on the second buffer layer 70, the damage to the light-emitting layer 20 caused by the vaporization or doping process during the preparation of the hole functional layer 50 can be avoided.

[0210] Fifthly, this application also provides a display device, which includes the light-emitting device 100.

[0211] 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.

[0212] The present application will be specifically described below through specific embodiments. These embodiments are only some embodiments of the present application and are not intended to limit the present application. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0213] Thin Film Example 1

[0214] A dispersion is provided, wherein the dispersion comprises ZnO nanoparticles, carbon quantum dots and ethanol, wherein the concentration of ZnO nanoparticles is 25 mg / mL, the concentration of carbon quantum dots is 5 mg / mL, and the mass ratio of carbon quantum dots to ZnO nanoparticles is 0.2:1.

[0215] The dispersion was spin-coated onto the substrate at 3000 rpm for 30 s, and then dried under low pressure of 0.01 Pa to remove the solvent, resulting in a pre-formed film with a thickness of 40 nm.

[0216] The pre-formed membrane was irradiated with oxygen ions at a dose of 1 × 10⁻⁶. 14 ion / cm 2 The irradiation time was 10 min, and a porous base film was obtained;

[0217] The porous base membrane was then irradiated with Mg ions to dope it with Mg, with a Mg ion dose of 1 × 10⁻⁶. 12 ion / cm 2 The irradiation time was 10 min, and a thin film with a thickness of 40 nm was obtained.

[0218] The thin film in this embodiment includes a porous base film and a dopant element Mg. The porous base film is made of ZnO nanoparticles, and the pores of the porous base film contain MgO nanoparticles. The ZnO nanoparticles are doped with Mg elements inside and on the surface.

[0219] Thin Film Example 2

[0220] This embodiment is basically the same as Embodiment 1, except that the dose of oxygen ion irradiation in this embodiment is 1×10⁻⁶. 12 ions / cm 2 .

[0221] Thin Film Example 3

[0222] This embodiment is basically the same as Embodiment 1, except that the dose of oxygen ion irradiation in this embodiment is 1×10⁻⁶. 20 ions / cm 2 .

[0223] Thin Film Example 4

[0224] This embodiment is basically the same as Embodiment 1, except that the dose of Mg ion irradiation in this embodiment is 1×10⁻⁶. 12 ions / cm 2 .

[0225] Thin Film Example 5

[0226] This embodiment is basically the same as Embodiment 1, except that the dose of Mg ion irradiation in this embodiment is 1×10⁻⁶. 20 ions / cm 2 .

[0227] Thin Film Example 6

[0228] This embodiment is basically the same as Embodiment 1, except that Cu ions are used to replace Mg ions in Embodiment 1.

[0229] Thin Film Example 7

[0230] This embodiment is basically the same as Embodiment 1, except that SnO2 nanoparticles are used to replace ZnO nanoparticles in Embodiment 1.

[0231] Thin Film Example 8

[0232] This embodiment is basically the same as Embodiment 1, except that in this embodiment, poly(3-hexylthiophene) quantum dots are used instead of carbon quantum dots in Embodiment 1.

[0233] Thin Film Example 9

[0234] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the concentration of carbon quantum dots is 1.25 mg / mL and the mass ratio of carbon quantum dots to ZnO nanoparticles is 0.05:1.

[0235] Thin Film Example 10

[0236] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the concentration of carbon quantum dots is 12.5 mg / mL and the mass ratio of carbon quantum dots to ZnO nanoparticles is 0.5:1.

[0237] Thin Film Example 11

[0238] This embodiment is basically the same as Embodiment 1, except that, in this embodiment, after irradiating the porous base membrane with Mg ions and before obtaining the thin film, it further includes: irradiating the porous base membrane with Ag ions to dope the porous base membrane with Ag elements, with an ion dose of 10. 12 ion / cm, treatment time 2min.

[0239] The thin film in this embodiment includes a porous base film, doped elements Mg and Ag. The porous base film is made of ZnO nanoparticles. The pores of the porous base film contain MgO nanoparticles and AgO nanoparticles. The ZnO nanoparticles are doped with Mg and Ag elements inside and on the surface.

[0240] Thin Film Example 12

[0241] A dispersion is provided, wherein the dispersion comprises NiO nanoparticles, carbon quantum dots and ethanol, wherein the concentration of NiO nanoparticles is 25 mg / mL, the concentration of carbon quantum dots is 5 mg / mL, and the mass ratio of carbon quantum dots to NiO nanoparticles is 0.2:1.

[0242] The dispersion was spin-coated onto the substrate at 3000 rpm for 30 s, and then dried under low pressure of 0.01 Pa to remove the solvent, resulting in a pre-formed film with a thickness of 40 nm.

[0243] The pre-formed membrane was irradiated with oxygen ions at a dose of 1 × 10⁻⁶. 14 A porous base film was obtained by irradiating at ion / cm for 10 min.

[0244] The porous substrate membrane was then irradiated with P ions to dope it with P elements; the P ion dose was 1 × 10⁻⁶. 12 An ion / cm irradiation time of 10 min yielded a thin film with a thickness of 40 nm.

[0245] The thin film in this embodiment includes a porous base film and a dopant element P. The porous base film is made of NiO nanoparticles, and the pores of the porous base film contain phosphorus oxide nanoparticles. The ZnO nanoparticles are doped with P element inside and on the surface.

[0246] Thin Film Example 13

[0247] This embodiment is basically the same as Embodiment 12, except that in this embodiment, Si ions are used to replace P ions in Embodiment 12.

[0248] Thin Film Example 14

[0249] This embodiment is basically the same as embodiment 12, except that in this embodiment, MoO3 nanoparticles are used to replace the NiO nanoparticles in embodiment 12.

[0250] Thin Film Example 15

[0251] This embodiment is basically the same as embodiment 12, except that in this embodiment, oligothiophene (OT) quantum dots are used instead of carbon quantum dots in embodiment 12.

[0252] Thin Film Example 16

[0253] This embodiment is basically the same as Embodiment 12, except that, in this embodiment, after irradiating the porous base film with P ions and before obtaining the thin film, it further includes: irradiating the porous base film with In ions to dope the porous base film with In element, with an ion dose of 1×10⁻⁶. 12 ion / cm, processing time 2min.

[0254] The thin film in this embodiment includes a porous base film, a dopant element P, and a dopant element In. The porous base film is made of NiO nanoparticles, and the pores of the porous base film contain phosphorus oxide nanoparticles and indium oxide nanoparticles. The ZnO nanoparticles are doped with P and In elements inside and on the surface.

[0255] Thin Film Comparative Example 1

[0256] A dispersion is provided, the dispersion comprising Mg-doped ZnO nanoparticles and ethanol, wherein the concentration of Mg-doped ZnO nanoparticles is 30 mg / mL and the mass percentage of Mg in the Mg-doped ZnO nanoparticles is 15%.

[0257] The dispersion was spin-coated onto the substrate at 4000 rpm for 30 s, and then dried under low pressure of 0.01 Pa to remove the solvent, resulting in a film with a thickness of 40 nm.

[0258] The thin film in this embodiment includes Mg-doped ZnO nanoparticles.

[0259] Thin Film Comparative Example 2

[0260] This comparative example is basically the same as thin film comparative example 1, except that Cu-doped ZnO nanoparticles are used in this comparative example to replace Mg-doped ZnO nanoparticles in thin film comparative example 1.

[0261] Thin Film Comparative Example 3

[0262] This comparative example is basically the same as thin film comparative example 1, except that this comparative example uses P-doped NiO nanoparticles to replace the Mg-doped ZnO nanoparticles in thin film comparative example 1.

[0263] Thin film comparative example 4

[0264] This comparative example is basically the same as thin film comparative example 1, except that this comparative example uses Si-doped NiO nanoparticles to replace the Mg-doped ZnO nanoparticles in thin film comparative example 1.

[0265] Thin film comparative example 5

[0266] This comparative example is basically the same as the thin film comparative example 1, except that the P-doped MoO3 nanoparticles in this comparative example replace the Mg-doped ZnO nanoparticles in the thin film comparative example 1.

[0267] Device Example 1

[0268] First, the substrate coated with ITO anode was ultrasonically cleaned with acetone and ethanol for 15 minutes, then rinsed with deionized water and dried. Next, it was dried on a heating plate at 150°C for 10 minutes, and then irradiated with ultraviolet light (UV) for 20 minutes to increase the work function of ITO.

[0269] PEDOT:PSS material (2.8% by mass) was spin-coated onto an ITO anode at 3000 rpm for 30 s, followed by heating on a 150°C heating plate for 20 min to obtain a hole injection layer with a thickness of 20 nm.

[0270] The substrate was placed in an inert atmosphere, and TFB material with a concentration of 8 mg / mL was spin-coated onto the hole injection layer at a speed of 3000 rpm for 30 s. Then it was heated on a heating plate at 150°C for 20 min to obtain a hole transport layer with a thickness of 25 nm.

[0271] A CdZnSe / ZnSe / CdZnS / ZnS quantum dot material with a concentration of 30 mg / mL was spin-coated onto the hole transport layer at a rotation speed of 2000 rpm for 30 s, and then heated on an 80°C heating plate for 5 min to obtain a light-emitting layer with a thickness of 30 nm.

[0272] An electron transport layer with a thickness of 40 nm was prepared on the light-emitting layer using the preparation method of Thin Film Example 1;

[0273] Ag is deposited on the electron transport layer by thermal evaporation with a vacuum degree not exceeding 3 × 10⁻⁶. -4 Pa, velocity of 1 angstrom / second, time of 1000s, yielded a cathode with a thickness of 100nm;

[0274] Encapsulation yields a positively positioned quantum dot light-emitting diode.

[0275] Device Examples 2-11

[0276] Device Examples 2-11 are basically the same as Device Example 1, except that Device Examples 2-11 respectively use the preparation method of Thin Film Examples 2-11 to prepare an electron transport layer with a thickness of 40 nm on the light-emitting layer.

[0277] Device Example 12

[0278] Device Example 12 is basically the same as Device Example 1, except that Device Example 12 further includes the following steps before fabricating the electron transport layer:

[0279] A ZnO nanoparticle solution with a concentration of 5 mg / mL was spin-coated onto the luminescent layer at a speed of 3000 rpm for 30 s. The solution was then dried under a low pressure of 0.01 Pa to remove the solvent, resulting in a first buffer layer with a thickness of 6 nm.

[0280] Device Example 13

[0281] First, the substrate coated with ITO anode was ultrasonically cleaned with acetone and ethanol for 15 minutes, then rinsed with deionized water and dried. Next, it was dried on a heating plate at 150°C for 10 minutes, and then irradiated with ultraviolet light (UV) for 20 minutes to increase the work function of ITO.

[0282] A hole transport layer with a thickness of 25 nm was prepared on the anode using the preparation method of Thin Film Example 12.

[0283] A CdZnSe / ZnSe / CdZnS / ZnS quantum dot material with a concentration of 30 mg / mL was spin-coated onto the hole transport layer at a rotation speed of 2000 rpm for 30 s, and then heated on an 80°C heating plate for 5 min to obtain a light-emitting layer with a thickness of 30 nm.

[0284] A dispersion is provided, comprising Mg-doped ZnO nanoparticles and ethanol, wherein the concentration of the Mg-doped ZnO nanoparticles is 30 mg / mL and the mass percentage of Mg in the Mg-doped ZnO nanoparticles is 15%; the dispersion is spin-coated onto the luminescent layer at 4000 rpm for 30 s, and then dried under a low pressure of 0.01 Pa to remove the solvent, resulting in an electron transport layer with a thickness of 40 nm;

[0285] Al is deposited on the electron transport layer by thermal evaporation with a vacuum degree not exceeding 3 × 10⁻⁶. -4 Pa, velocity of 1 angstrom / second, time of 1000s, yielded a cathode with a thickness of 100nm;

[0286] Encapsulation yields a positively positioned quantum dot light-emitting diode.

[0287] Device Examples 14-17

[0288] Device Examples 14-17 are basically the same as Device Example 13, except that Device Examples 14-17 respectively use the preparation methods of Thin Film Examples 13-16 to prepare a hole transport layer with a thickness of 25 nm on the anode.

[0289] Device Comparison Examples 1-2

[0290] The devices in Comparative Examples 1 and 2 are basically the same as those in Device Example 1, except that the electron transport layer in Comparative Examples 1 and 2 is prepared using the same method as that in Comparative Examples 1 and 2.

[0291] Device Comparison Examples 3-5

[0292] The devices in Comparative Examples 3 to 5 are basically the same as those in Device Example 13, except that the hole transport layer in Comparative Examples 3 to 5 is prepared using the same method as that in Comparative Examples 3 to 5.

[0293] Electrical performance tests were performed on the light-emitting devices of Device Examples 1, 11, 12 and Device Comparative Example 1, and the results were obtained. Figure 9 The JV curve (current density-voltage curve) shown is shown below. Figure 10 The CE-L curve shown (current efficiency η) A - Brightness L curve) diagram.

[0294] The JVL test method is as follows: The efficiency test system was built by controlling the QE PRO spectrometer, Keithley 2400, and Keithley 6485 through LabVIEW. The driving voltage was 0-8V with a step size of 0.1V. The current density-voltage curve and the current efficiency-brightness curve were plotted.

[0295] Depend on Figure 9 It can be seen that, under the same voltage, the current density of the light-emitting device in Device Examples 11 and 12 is higher than that of the light-emitting device in Device Comparative Example 1; under the same voltage, at low voltage, the current density of the light-emitting device in Device Example 1 is higher than that of the light-emitting device in Device Comparative Example 1.

[0296] Depend on Figure 10 It can be seen that, under the same brightness, the current efficiency of the light-emitting devices in Device Examples 1, 11, and 12 is higher than that of the light-emitting device in Device Comparative Example 1.

[0297] The porosity of the films in Thin Film Examples 1 to 16 and the films in Thin Film Comparative Examples 1 to 5 were tested respectively, and the test results are shown in Table 1 below.

[0298] The maximum brightness L of the light-emitting devices in Device Examples 1-17 and Device Comparative Examples 1-5 were tested respectively. max The lifespan tests were conducted at T95 and T95@1000nit, and the test results are shown in Table 1.

[0299] Among them, the maximum brightness L max The lifetime T95 and lifetime T95@1000nit test methods are as follows: In CDA gas, under constant current or voltage drive, the time it takes for the device brightness to decay to a certain percentage of its maximum brightness is measured. The time for the brightness to decay to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the lifetime testing cycle, device lifetime testing is usually performed at high brightness by accelerating device aging, and the lifetime at low brightness is obtained by fitting the decay fitting formula. For example, the lifetime at 1000 nits is denoted as T95@1000nits, and the calculation formula is:

[0300]

[0301] Among them, T95 L The lifespan at low brightness is typically taken as the lifespan at 1000 nits, T95. H The lifetime at high brightness, i.e., the measured lifetime, L H L is the maximum brightness that the device accelerates to. L Typically, it is 1000 nits, where A is the acceleration factor, taken as 1.7. The constant current is 1 mA.

[0302] Table 1:

[0303]

[0304]

[0305] As shown in Table 1:

[0306] Compared to the films in Comparative Examples 1 to 5, the films in Examples 1 to 16 have significantly higher porosity.

[0307] Compared to the light-emitting device in Comparative Example 1, the light-emitting devices in Examples 1-5 and 7-12 exhibit higher maximum brightness and longer lifespan; compared to the light-emitting device in Comparative Example 2, the light-emitting device in Example 6 exhibits higher maximum brightness and longer lifespan. It is evident that using the thin film described in this application as an electron transport layer can effectively improve the brightness and lifespan of the light-emitting device. This may be because the porous base film of this application has a lower electron mobility compared to a continuous thin film; furthermore, by depositing dopant elements in the porous base film, the electron-hole injection of the light-emitting device can be more balanced, thereby effectively improving the brightness and lifespan of the light-emitting device.

[0308] Compared to the light-emitting device of Device Example 1, the light-emitting device of Device Example 11 has a higher maximum brightness and a longer lifespan. This may be because the electron transport layer is doped with electrode metal elements, which can improve the interface stability between the electron transport layer and the cathode, reduce the interface contact barrier between the electron transport layer and the cathode, and promote the interface reaction between the electron transport layer and the cathode.

[0309] Compared to the light-emitting device in Comparative Example 3, the light-emitting devices in Device Examples 13, 16-17 exhibit higher maximum brightness and longer lifetime; compared to the light-emitting device in Comparative Example 4, the light-emitting device in Device Example 14 exhibits higher maximum brightness and longer lifetime; and compared to the light-emitting device in Comparative Example 5, the light-emitting device in Device Example 15 exhibits higher maximum brightness and longer lifetime. It is evident that using the thin film described in this application as a hole transport layer can effectively improve the brightness and lifetime of the light-emitting device. This is likely because by depositing doping elements in the porous base film, a higher doping concentration can be obtained, which allows for a more balanced electron-hole injection in the light-emitting device, thereby effectively improving its brightness and lifetime.

[0310] The technical solutions provided by 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 description of the above embodiments is only for the purpose of helping to understand the method 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 thin film, characterized in that, The thin film includes a porous base film, the material of which includes first nanoparticles and has pores. The thin film also includes second nanoparticles located in the pores of the porous base film.

2. The thin film as described in claim 1, characterized in that, The porosity of the film is 8–14%; and / or The porosity of the porous base membrane is 25-60%; and / or The second nanoparticles adhere to the pore walls of the porous substrate membrane; and / or The average particle size of the first nanoparticle is 2–20 nm; and / or The average pore size of the porous base membrane is 2–20 nm.

3. The thin film as described in claim 1, characterized in that, The first nanoparticle is either a doped first nanoparticle or an undoped first nanoparticle, wherein the doped first nanoparticle is doped with a first element; and / or The second nanoparticle contains the first element.

4. The thin film as described in claim 3, characterized in that, In the thin film, the molar content of the first element is less than or equal to 50%.

5. The thin film as described in claim 3, characterized in that, The first nanoparticle is an N-type inorganic nanoparticle, wherein, The N-type inorganic nanoparticles include one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. Specifically, the first metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3; the group IIB-VIA inorganic particles are made of one or more of ZnS, ZnSe, and CdS; the group IIIA-VA inorganic particles are made of one or more of InP and GaP; and the group IB-IIIA-VIA inorganic particles are made of one or more of CuInS and CuGaS; and / or The first element includes one or more of Al, Ag, In, W, Mo, Sn, V, Fe, Mg, Co, B, Ca, Cu, Zn, and F; and / or The material of the second nanoparticle includes one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide.

6. The thin film as described in claim 3, characterized in that, The first nanoparticle is a p-type inorganic nanoparticle, wherein, The p-type inorganic nanoparticles comprise one or more of a second metal oxide particle, a metal sulfide, and a metal nitride. The second metal oxide particle is made of one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfide comprises one or more of CuS, MoS3, and WS3. The metal nitride comprises p-type gallium nitride. and / or The first element includes one or more of Li, Mg, Al, K, Ca, Co, S, P, Cl, N, Si, As, F, and Cu; and / or The material of the second nanoparticle includes one or more of lithium oxide, magnesium oxide, aluminum oxide, potassium oxide, calcium oxide, cobalt oxide, phosphorus oxide, silicon oxide, arsenic oxide, and copper oxide.

7. The thin film as described in claim 3, characterized in that, The first nanoparticle is either the doped first nanoparticle or the undoped first nanoparticle, wherein the doped first nanoparticle is further doped with a second element; and / or The film also includes a third nanoparticle located in the pores of the porous base film, and the cation in the third nanoparticle contains a second element.

8. The thin film as claimed in claim 7, characterized in that, The third nanoparticles are attached to the pore walls of the porous substrate membrane; and / or The second element includes one or more of Ag, Al, Ni, Pt, Au, Ir, Cu, Mo, Ca, Mg, Ba, In, and Sn; and / or The material of the third nanoparticle includes one or more of the following: aluminum oxide, silver oxide, indium oxide, tungsten oxide, molybdenum oxide, tin oxide, vanadium oxide, iron oxide, magnesium oxide, cobalt oxide, boron oxide, calcium oxide, copper oxide, and zinc oxide; and / or In the thin film, the molar content of the second element is less than or equal to 30%.

9. A method for preparing a thin film, characterized in that, Includes the following steps: A dispersion is provided, the dispersion comprising first nanoparticles, organic nanoparticles and a first solvent; the dispersion is placed on a substrate and dried to obtain a pre-formed film. The organic nanoparticles in the pre-formed membrane are vaporized to obtain a porous base membrane; as well as The porous substrate is subjected to a first doping treatment with a first element to obtain the thin film.

10. The preparation method according to claim 9, characterized in that, The organic nanoparticles include one or more of the following: carbon quantum dots, oligobenzopyran quantum dots, oligobenzothiophene quantum dots, oligothiophene quantum dots, oligopyrrole quantum dots, oligostyrene quantum dots, polystyrene quantum dots, oligo-terephthalene quantum dots, poly(3-hexylthiophene) quantum dots, poly(terephthal-2,7-divinylbenzene) quantum dots, and poly(benzopyrrole vinyl oxide) quantum dots; and / or The organic nanoparticles have an average particle size of 4–20 nm; and / or The mass ratio of the organic nanoparticles to the first nanoparticles is (0.05–0.5):1; and / or In the dispersion, the mass concentration of the first nanoparticles is 5–50 mg / mL; and / or The first solvent includes one or more of alcohol solvents and ether solvents, wherein the alcohol solvent includes one or more of ethanol, isopropanol, butanol, n-pentanol, and isoamyl alcohol, and the ether solvent includes ethylene glycol monomethyl ether; and / or The porosity of the porous base membrane is 25-60%; and / or The porosity of the film is 8–14%; and / or The average pore size of the porous base membrane is 2–20 nm.

11. The preparation method according to claim 9, characterized in that, The gasification treatment includes oxygen ion treatment, which includes one or more of oxygen ion irradiation and oxygen plasma treatment. Optionally, the dose of the oxygen ion treatment is 1×10⁻⁶. 12 ~1×10 20 ions / cm 2 The time is 2–30 minutes; and / or The gasification treatment includes one or more of ozone treatment and peroxide gas treatment. Optionally, the temperature of the ozone treatment and peroxide gas treatment is 100-150°C.

12. The preparation method according to claim 9, characterized in that, The first doping process includes one or more of the following: ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering; and / or The dose of the first doping treatment is 1×10 12 ~1×10 20 ions / cm 2 The time is 5 to 30 minutes.

13. The preparation method according to claim 12, characterized in that, After performing a first doping treatment on the porous base film with a first element and before obtaining the thin film, the method further includes: performing a second doping treatment on the porous base film with a second element; Optionally, the second doping process includes one or more of the following: ion beam implantation, ion beam-assisted deposition, ion irradiation, vapor deposition, pulsed laser deposition, and magnetron sputtering; and / or Optionally, the dose of the second doping treatment is 1×10⁻⁶. 12 ~1×10 20 ions / cm 2 The time is 5 to 30 minutes; and / or The ratio of the time for the first doping treatment to the time for the second doping treatment is 1:(0.05~0.5).

14. A light-emitting device, characterized in that, The system comprises an anode, a light-emitting layer, and a cathode stacked sequentially, and further comprises an electronic functional layer located between the light-emitting layer and the cathode and / or a hole functional layer located between the anode and the light-emitting layer, wherein... The electronic functional layer is the thin film according to any one of claims 1 to 8, or the electronic functional layer is the thin film prepared by the preparation method according to any one of claims 9 to 13; and / or, The hole-functional layer is the thin film according to any one of claims 1 to 8, or the hole-functional layer is the thin film prepared by the preparation method according to any one of claims 9 to 13.

15. The light-emitting device as described in claim 14, characterized in that, The electronic functional layer further includes the second element, and the type of the second element is the same as the type of metal in the cathode; and / or The hole functional layer further includes the second element, and the type of the second element is the same as the type of metal in the anode; and / or The light-emitting device further includes a first buffer layer located between the light-emitting layer and the electronic functional layer, wherein the material of the first buffer layer comprises N-type inorganic particles; and / or The light-emitting device also includes a second buffer layer located between the hole-functional layer and the light-emitting layer, and the material of the second buffer layer includes P-type inorganic particles.

16. The light-emitting device as described in claim 15, characterized in that, The N-type inorganic particles include one or more of the following: first metal oxide particles, group IIB-VIA inorganic particles, group IIIA-VA inorganic particles, and group IB-IIIA-VIA inorganic particles. The first metal oxide particles are made of one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The group IIB-VIA inorganic particles include one or more of ZnS, ZnSe, and CdS. The group IIIA-VA inorganic particles include one or more of InP and GaP. The group IB-IIIA-VIA inorganic particles include one or more of CuInS and CuGaS; and / or The P-type inorganic particles include one or more of a second metal oxide particle, a metal sulfide, and a metal nitride. The material of the second metal oxide particle includes one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The metal sulfide includes one or more of CuS, MoS3, and WS3. The metal nitride includes P-type gallium nitride; and / or The thickness of the first buffer layer is 5–20 nm; and / or The thickness of the second buffer layer is 5–20 nm.

17. The light-emitting device as described in claim 16, characterized in that, The N-type inorganic particles also include a third element, which comprises one or more of the following: Al, Ag, In, W, Mo, Sn, V, Fe, Mg, Co, B, Ca, Cu, Zn, and F; and / or The P-type inorganic particles also include a fourth element, which includes one or more of Li, Mg, Al, K, Ca, Co, S, P, Cl, N, Si, As, F, and Cu.

18. The light-emitting device as described in claim 14, characterized in that, The anode and the cathode each independently comprise a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode, or an alloy electrode. The doped metal oxide electrode is made of one or more of the following materials: indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrode comprises AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, and ZnO / Ag / ZnO. The metal element electrode comprises one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba, and the alloy electrode comprises an Au:Mg alloy electrode or an Ag:Mg alloy electrode; and / or The material of the light-emitting layer includes one or more of organic light-emitting materials and quantum dot light-emitting materials. The organic light-emitting materials include one or more of the following: 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridinium(III), 4,4',4”-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridinium, diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, thermally activated delayed materials, polymers containing BN covalent bonds, hybrid local charge transfer excited state materials, excitopolymer light-emitting materials, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives.The quantum dot luminescent material comprises one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite-type inorganic particles. The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots are each independently selected from one or more of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, and ZnS. Te, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the IV-VI group compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, and the III-V compound includes one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and GaAl The perovskite inorganic particles are selected from one or more of NAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, and the I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2; the perovskite inorganic particles include doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors, and the general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + Ions, where M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation, including Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ One or more of them, where X is a halide anion, including Cl. - ,Br - I - One or more of them.

19. A display device, characterized in that, Includes the light-emitting device according to any one of claims 14 to 18.

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