Light-emitting devices, methods for fabricating light-emitting devices, and display devices

Abstract

This application discloses a light-emitting device, a method for fabricating the light-emitting device, and a display device. The light-emitting device includes an anode, a cathode, a light-emitting layer, and a hole-functional layer. The anode and cathode are disposed opposite each other, the light-emitting layer is disposed between the anode and cathode, and the hole-functional layer is disposed between the anode and the light-emitting layer. The material of the hole-functional layer includes compound A and compound B. Compound A and compound B can self-assemble to form a stable ordered structure, effectively improving hole injection and promoting hole-electron transport balance, thereby improving the overall performance of the light-emitting device. In the fabrication method, the hole-functional layer is prepared by applying a mixture containing compound A and compound B to one side of the anode or one side of the light-emitting layer, and then drying it into a film. This eliminates the need to separately prepare compound A and compound B layers, which simplifies the fabrication process, reduces manufacturing costs, and is suitable for industrial production.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technology, specifically to a light-emitting device, a method for fabricating the light-emitting device, and a display device. Background Technology

[0002] Light-emitting devices include, but are not limited to, organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs). These devices have a "sandwich" structure, consisting of an anode, a cathode, and a light-emitting layer. The anode and cathode are positioned opposite each other, and the light-emitting layer is located between them. The principle of light emission is as follows: electrons are injected from the cathode into the light-emitting region, and holes are injected from the anode. Electrons and holes recombine in the light-emitting region to form excitons. These excitons then release photons through radiative transitions, thus emitting light.

[0003] Currently, an electron-hole transport imbalance exists in light-emitting devices, particularly severe in QLEDs. This imbalance manifests as a lower hole injection level compared to electron injection, leading to decreased photoelectric performance and shortened lifespan. Therefore, addressing this electron-hole transport imbalance is crucial for the application and development of light-emitting devices. Summary of the Invention

[0004] This application provides a light-emitting device, a method for fabricating the light-emitting device, and a display device, which improves the problem of excessive difference between electron mobility and hole mobility in light-emitting devices.

[0005] The technical solution of this application is as follows:

[0006] In a first aspect, this application provides a light-emitting device, comprising: an anode;

[0007] The cathode is disposed opposite to the anode;

[0008] A light-emitting layer is disposed between the anode and the cathode; and

[0009] A hole-functional layer is disposed between the anode and the light-emitting layer;

[0010] The hole functional layer is made of compound A and compound B, wherein compound A is poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), and compound B has the structure shown in general formula (I):

[0011]

[0012] In general formula (I), R1 and R2 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, groups containing aryl groups, groups containing aryloxy groups, and groups containing -CO-R s Groups or containing -CO-OR t The group, wherein R s and R t The groups are selected independently from each other, either from alkyl groups having 1 to 10 carbon atoms or from aryl groups;

[0013] R3 to R7 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, cyano, nitro or halogen atoms.

[0014] At least one of R1 to R7 is selected from a group containing a perfluoroalkyl group having 1 to 10 carbon atoms.

[0015] Furthermore, R1 and R2 are independently selected from groups comprising cycloalkyl groups having 3 to 6 carbon atoms, groups comprising perfluoroalkyl groups having 1 to 10 carbon atoms, groups comprising phenyl groups, groups comprising phenoxy groups, and groups comprising -CO-R groups. s Groups or containing -CO-OR t The group, wherein R s Selected from at least one of haloalkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, or phenyl groups, R t It is selected from at least one of a haloalkyl or phenyl group having 1 to 10 carbon atoms.

[0016] Further, R1 or R2 is selected from phenyl groups containing perfluoroalkyl groups.

[0017] Furthermore, R3 to R7 are independently selected from at least one of cycloalkyl groups having 3 to 6 carbon atoms or perfluoroalkyl groups having 1 to 10 carbon atoms.

[0018] Furthermore, R3 to R7 are selected from alkyl groups having 3 to 6 carbon atoms, and at least one of R3 to R7 is a perfluoroalkyl group having 1 to 4 carbon atoms.

[0019] Furthermore, compound B is selected from:

[0020]

[0021] At least one of them.

[0022] Furthermore, in the hole-functional layer, the mass ratio of compound A to compound B is 1:(1-10);

[0023] Preferably, the mass ratio of compound A to compound B is 1:(5-8).

[0024] Furthermore, the material of the light-emitting layer includes organic light-emitting materials or quantum dots;

[0025] The organic light-emitting material is selected from at least one of diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent material emitting blue light, TTPA fluorescent material emitting green light, TBRb fluorescent material emitting orange light, and DBP fluorescent material emitting red light.

[0026] The quantum dots are selected from at least one of group II-VI, III-V, IV-VI, and I-III-VI compounds, wherein the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and CdZnTe. At least one of CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and Ga NP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAl NAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPA The compounds are selected from at least one of SnS and InAlPSb, wherein the group IV-VI compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, and the group I-III-VI compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.

[0027] Furthermore, the light-emitting device further includes an electron transport layer disposed between the cathode and the light-emitting layer. The material of the electron transport layer includes nano-metal oxides, which are selected from at least one of ZnO, TiO2, SnO2, Ta2O3, ZrO2, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, and AlZnO.

[0028] Thirdly, this application provides a method for fabricating a light-emitting device, the method comprising the following steps:

[0029] A mixture comprising compound A and compound B is provided;

[0030] An anode is provided, the mixture is applied to one side of the anode, and then dried to form a film to obtain a hole-functionalized layer;

[0031] A light-emitting layer is formed on the side of the hole-functional layer away from the anode;

[0032] A cathode is formed on the side of the light-emitting layer away from the hole-functional layer;

[0033] Alternatively, the preparation method includes the following steps:

[0034] A cathode is provided, and a light-emitting layer is formed on one side of the cathode;

[0035] A mixture comprising compound A and compound B is provided, the mixture is applied to one side of the cathode, and then dried to form a film to obtain a hole-functional layer;

[0036] An anode is formed on the side of the hole functional layer away from the light-emitting layer;

[0037] Wherein, compound A is poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), and compound B has the structure shown in general formula (I):

[0038]

[0039] In general formula (I), R1 and R2 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, groups containing aryl groups, groups containing aryloxy groups, and groups containing -CO-R s Groups or containing -CO-OR t The group, wherein R s and R t The groups are selected independently from each other, either from alkyl groups having 1 to 10 carbon atoms or from aryl groups;

[0040] R3 to R7 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, cyano, nitro or halogen atoms.

[0041] At least one of R1 to R7 is selected from a group containing a perfluoroalkyl group having 1 to 10 carbon atoms.

[0042] Furthermore, in the mixture, the mass ratio of compound A to compound B is 1:(1 to 10);

[0043] Preferably, the mass ratio of compound A to compound B is 1:(5-8).

[0044] Fourthly, this application provides a display device, which includes a light-emitting device as described in any of the first aspects, or a light-emitting device prepared by any of the preparation methods described in the second aspect.

[0045] This application provides a light-emitting device, a method for fabricating the light-emitting device, and a display device, which have the following technical advantages:

[0046] In the light-emitting device of this application, the hole functional layer comprises compounds A and B. Due to the non-covalent interaction between the large π bond of compound B and the PEDOT of compound A, a stable ordered structure is formed through self-assembly. Specifically, compounds A and B maintain a certain spatial structure through a dispersed and varying electromagnetic force, spontaneously organizing or aggregating into a stable structure with a certain regular geometric appearance. Furthermore, the lower surface energy of compound B allows it to aggregate on top of compound A. This is equivalent to the hole functional layer comprising two layers: compound A and compound B. Compound A acts as a "hole injection layer," and compound B acts as a "hole transport layer." Because compounds A and B self-assemble to form a stable ordered structure, the potential energy barrier between the two layers is low, effectively improving hole injection and promoting hole-electron transport balance. This, in turn, improves the luminous efficiency of the light-emitting device, reduces its operating voltage, and helps extend its lifespan.

[0047] In the method for fabricating the light-emitting device of this application, the hole functional layer is prepared by applying a mixture of compound A and compound B to one side of the anode or one side of the light-emitting layer, and then drying it into a film. This eliminates the need to prepare compound A layer and compound B layer separately, which simplifies the fabrication process and reduces manufacturing costs, and is suitable for industrial production.

[0048] Applying the light-emitting device of this application to a display device is beneficial to improving the display effect and service life of the display device. Attached Figure Description

[0049] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0050] Figure 1This is a schematic diagram of the structure of the first light-emitting device provided in the embodiments of this application.

[0051] Figure 2 This is a schematic diagram of the structure of the second type of light-emitting device provided in the embodiments of this application.

[0052] Figure 3 This is a schematic flowchart illustrating the fabrication method of the first light-emitting device provided in the embodiments of this application.

[0053] Figure 4 This is a schematic flowchart illustrating the fabrication method of the second light-emitting device provided in the embodiments of this application.

[0054] Figure 5 This is a schematic diagram of the structure of the third type of light-emitting device provided in the embodiments of this application.

[0055] Figure 6 The current density-voltage curves of the structured device used for hole mobility testing in the experimental examples of this application. Figure 1 .

[0056] Figure 7 The current density-voltage curves of the structured device used for hole mobility testing in the experimental examples of this application. Figure 2 .

[0057] Figure 8 This is a current density-voltage curve of the structural device used for electron mobility testing in the experimental examples of this application. Detailed Implementation

[0058] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0060] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". 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 rigid limitation on the scope of the invention; 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 digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0061] This application provides a light-emitting device, such as... Figure 1 As shown, the light-emitting device 1 includes an anode 11, a cathode 12, a light-emitting layer 13, and a hole-functional layer 14. The anode 11 and cathode 12 are disposed opposite each other, the light-emitting layer 13 is disposed between the anode 11 and cathode 12, and the hole-functional layer 14 is disposed between the anode 11 and the light-emitting layer 13. The material of the hole-functional layer 14 includes compound A and compound B. Compound A is poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), and compound B has the structure shown in the following general formula (Ⅰ):

[0062]

[0063] In general formula (I), R1 and R2 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, groups containing aryl groups, groups containing aryloxy groups, and groups containing -CO-R s Groups or containing -CO-OR t The group, wherein R s and R t The groups are selected independently from each other, either from alkyl groups having 1 to 10 carbon atoms or from aryl groups;

[0064] R3 to R7 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, cyano, nitro or halogen atoms.

[0065] At least one of R1 to R7 is selected from a group containing a perfluoroalkyl group having 1 to 10 carbon atoms.

[0066] As used in this application, "alkyl" includes both unsubstituted alkyl and substituted alkyl; "unsubstituted alkyl" refers to an aliphatic hydrocarbon group formed by losing one hydrogen atom from an alkane molecule, including straight-chain saturated aliphatic hydrocarbon groups, branched saturated aliphatic hydrocarbon groups, and cyclic saturated aliphatic hydrocarbon groups, and alkyl includes, but is not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, or cyclohexyl; "substituted alkyl" refers to a group obtained by optionally replacing one or more hydrogen atoms on an aliphatic hydrocarbon group with other groups, such as halogen atoms, and multiple degrees of substitution are allowed.

[0067] As used in this application, "perfluoroalkyl" refers to an aliphatic hydrocarbon group formed by losing one hydrogen atom from an alkane molecule, in which all hydrogen atoms are replaced by fluorine atoms to obtain the group.

[0068] As used in this application, "alkylthio" refers to a structure with the general formula R. x -S- groups, wherein R x Indicates alkyl group.

[0069] As used in this application, "alkoxy" refers to the general structural formula R. x -O- groups, wherein R x Indicates alkyl group.

[0070] As used in this application, "aryl" includes both unsubstituted and substituted aryl groups; "unsubstituted aryl" refers to an aromatic group containing only carbon atoms on an aromatic ring, including but not limited to phenyl, 1-naphthyl, 2-naphthyl, or biphenyl; "substituted aryl" refers to an aromatic group containing only carbon atoms on an aromatic ring where one or more hydrogen atoms are optionally replaced by other groups, such as halogen atoms or alkyl groups, and multiple degrees of substitution are permitted.

[0071] As used in this application, "aryloxy group" refers to a group with the general structural formula Ar-O-, where Ar represents an aryl group.

[0072] In some embodiments of this application, in general formula (I), R1 and R2 are independently selected from groups comprising cycloalkyl groups having 3 to 6 carbon atoms, groups comprising perfluoroalkyl groups having 1 to 10 carbon atoms, groups comprising phenyl groups, groups comprising phenoxy groups, groups comprising -CO-R groups, and groups comprising -CO-R groups. s Groups or containing -CO-OR t The group, wherein R s Selected from at least one of haloalkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, or phenyl groups, R t It is selected from at least one of a haloalkyl or phenyl group having 1 to 10 carbon atoms.

[0073] In some embodiments of this application, R1 or R2 is selected from phenyl groups containing perfluoroalkyl groups.

[0074] In one example of this application, R1 is selected from phenyl containing one or two substituents, and at least one substituent contains a perfluoroalkyl group. If the number of substituents exceeds two, the degree of fit between compound A and compound B is limited due to greater steric hindrance.

[0075] In another example of this application, R2 is selected from phenyl containing one or two substituents, and at least one substituent contains a perfluoroalkyl group. If the number of substituents exceeds two, the degree of fit between compound A and compound B is limited due to greater steric hindrance.

[0076] In some embodiments of this application, in general formula (I), R3 to R7 are independently selected from at least one of cycloalkyl groups having 3 to 6 carbon atoms or perfluoroalkyl groups having 1 to 10 carbon atoms.

[0077] In some embodiments of this application, R3 to R7 are selected from alkyl groups having 3 to 6 carbon atoms, and at least one of R3 to R7 is a perfluoroalkyl group having 1 to 4 carbon atoms.

[0078] In some embodiments of this application, compound B is selected from:

[0079]

[0080] At least one of them.

[0081] To facilitate the self-assembly of compound A and compound B, in some embodiments of this application, the mass ratio of compound A to compound B in the hole functional layer is 1:(1-10). Too much or too little compound B has limited effect on improving the performance of the light-emitting device.

[0082] In order to further improve the overall performance of the light-emitting device, in some embodiments of this application, the mass ratio of compound A to compound B in the hole functional layer is 1:(5-8).

[0083] In some embodiments of this application, the materials of the anode 11 and the cathode 12 are independently selected from one or more of metals, carbon materials, and metal oxides. The metals are selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg; the carbon materials are selected from at least one of graphite, carbon nanotubes, graphene, and carbon fibers; and the metal oxides can be doped or undoped metal oxides, selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO. The anode 11 or cathode 12 can also be independently selected from composite electrodes consisting of a metal sandwiched between doped or undoped transparent metal oxides. These composite electrodes include, but are not limited to, at least one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. The thickness of the anode 11 can be, for example, from 40 nm to 160 nm, and the thickness of the cathode 12 can be, for example, from 20 nm to 120 nm.

[0084] In some embodiments of this application, the material of the light-emitting layer 13 includes organic light-emitting materials or quantum dots, and the thickness of the light-emitting layer 13 can be, for example, 10 nm to 30 nm.

[0085] Organic light-emitting materials include, but are not limited to, at least one of the following: diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent materials emitting blue light, TTPA fluorescent materials emitting green light, TBRb fluorescent materials emitting orange light, and DBP fluorescent materials emitting red light.

[0086] The quantum dots can be at least one of red, green, and blue quantum dots, and are selected from at least one of group II-VI, III-V, IV-VI, and I-III-VI compounds. Specifically, the group I-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, and HgS. At least one of Te, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, I nP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPS b. GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAl At least one of NSb, InAlPAs, and InAlPSb; group IV-VI compounds selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; and group I-III-VI compounds selected from at least one of CuInS2, CuInSe2, and AgInS2.

[0087] In some embodiments of this application, such as Figure 2 As shown, in Figure 1Based on the light-emitting device shown, the light-emitting device 1 further includes an electron transport layer 15, which is disposed between the light-emitting layer 13 and the cathode 12. The material of the electron transport layer 15 includes nano-metal oxides, which can be either undoped or doped. For example, the nano-metal oxide is selected from at least one of ZnO, TiO2, SnO2, Ta2O3, ZrO2, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, and AlZnO. The thickness of the electron transport layer 15 can be, for example, from 10 nm to 60 nm.

[0088] It is understood that the light-emitting device in the embodiments of this application may also include other layer structures. For example, the light-emitting device may also include an electron injection layer disposed between the electron transport layer and the cathode. The material of the electron injection layer includes, but is not limited to, at least one of alkali metal halides, alkali metal organo-complexes, and organophosphorus compounds. Alkali metal halides include, but are not limited to, LiF. Alkali metal organo-complexes include, but are not limited to, lithium 8-hydroxyquinoline. Organophosphorus compounds include, but are not limited to, one or more of organophosphorus oxides, organothiophosphorus compounds, and organoselenophosphorus compounds.

[0089] In the light-emitting device of this application embodiment, the hole functional layer comprises compounds A and B. Due to the non-covalent interaction between the large π bond of compound B and the PEDOT of compound A, a stable ordered structure is formed through self-assembly. Specifically, compounds A and B maintain a certain spatial structure through a dispersed and varying electromagnetic force, spontaneously organizing or aggregating into a stable structure with a certain regular geometric appearance. Furthermore, the low surface energy of compound B allows it to aggregate on top of compound A. This is equivalent to the hole functional layer comprising two layers: compound A and compound B. Compound A acts as a "hole injection layer," and compound B acts as a "hole transport layer." Because compounds A and B self-assemble to form a stable ordered structure, the potential energy barrier between the two layers is low, effectively improving hole injection and promoting hole-electron transport balance. This, in turn, improves the luminous efficiency of the light-emitting device, reduces its operating voltage, and helps extend its lifespan.

[0090] This application also provides a method for fabricating a light-emitting device, such as... Figure 3 As shown, the preparation method includes the following steps:

[0091] S1. Provide a mixture comprising compound A and compound B;

[0092] S2. Provide an anode, apply the mixture from step S1 to one side of the anode, and then dry it to form a film to obtain a hole-functional layer;

[0093] S3. A light-emitting layer is formed on the side of the hole-functional layer away from the anode in step S2;

[0094] S4. A cathode is formed on the side of the light-emitting layer away from the hole-functional layer in step S3.

[0095] Or, such as Figure 4 As shown, the preparation method includes the following steps:

[0096] S1', Provide a cathode, and form a light-emitting layer on one side of the cathode;

[0097] S2', Provide a mixture containing compound A and compound B, apply the mixture to one side of the cathode in step S1', and then dry it into a film to obtain a hole-functional layer;

[0098] S3', An anode is formed on the side of the hole functional layer away from the light-emitting layer in step S2'.

[0099] In the above preparation method, steps S1 to S4 are suitable for preparing light-emitting devices with upright structures, and steps S1' to S3' are suitable for preparing light-emitting devices with inverted structures. Compound A is PEDOT:PSS, and compound B is a compound with the structure shown in general formula (I).

[0100] In some embodiments of this application, the mixture is applied using a solution method, which includes, but is not limited to, spin coating, coating, inkjet printing, blade coating, dip-coating, immersion, spraying, roller coating, or casting. "Drying to form a film" refers to all operations that can give the wet film higher energy and transform it into a dry film, including but not limited to heat treatment and natural air drying. Heat treatment can be either isothermal heat treatment or non-isothermal heat treatment (e.g., temperature gradient change).

[0101] It is understandable that the fabrication method of light-emitting devices may also include the fabrication steps of other film layers, such as fabricating an electron transport layer between the light-emitting layer and the cathode, or fabricating an electron injection layer between the electron transport layer and the cathode.

[0102] It should be noted that, apart from the hole functional layer, the preparation methods for other films in light-emitting devices include, but are not limited to, solution methods and deposition methods. Deposition methods include chemical methods and physical methods. Chemical methods include, but are not limited to, chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, or co-precipitation. Physical methods include, but are not limited to, thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, or pulsed laser deposition. Furthermore, if a solution method is used to prepare the film, the wet film obtained by the solution method needs to be dried to transform it into a dry film.

[0103] This application also provides a display device, which includes any of the light-emitting devices described in this application or light-emitting devices prepared by the methods described above. The display device can be any electronic product with display functionality, 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. Smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0104] The technical solutions and effects of this application will be described in detail below through specific embodiments, comparative examples and experimental examples. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0105] Example 1

[0106] This embodiment provides a light-emitting device and its fabrication method. The light-emitting device is a quantum dot light-emitting diode with a positive-position structure, such as... Figure 5 As shown, in the direction from bottom to top, the light-emitting device 1 includes a substrate 10, an anode 11, a hole functional layer 14, a light-emitting layer 13, an electron transport layer 15, and a cathode 12 arranged sequentially.

[0107] The materials and thicknesses of each layer in light-emitting device 1 are as follows:

[0108] The substrate 10 is made of glass and has a thickness of 2 mm;

[0109] Anode 11 is made of ITO and has a thickness of 80 nm;

[0110] The cathode 12 is made of Ag and has a thickness of 100 nm.

[0111] The material of the light-emitting layer 13 is Cd 0.10 Zn 0.9 Se / Cd 0.1 Zn 0.9The quantum dots of Se / ZnSe / ZnS have an emission wavelength of 465nm, a peak width of 21nm, and a thickness of 25nm.

[0112] The hole functional layer 14 is composed of compound A and compound B, with a mass ratio of compound A to compound B of 1:1. The thickness of the hole functional layer 14 is 35 nm. Compound A is PEDOT:PSS, and compound B has the structure shown in formula (1.1).

[0113]

[0114] The electron transport layer 15 is made of nano-ZnO with a particle size of 4nm to 6nm and a thickness of 30nm.

[0115] The fabrication method of the light-emitting device in this embodiment includes the following steps:

[0116] S1.1 Provide a substrate, deposit ITO on one side of the substrate to obtain an ITO layer, and then sequentially ultrasonically clean the substrate containing ITO with acetone for 15 min, ultrasonically clean with cleaning agent for 15 min, ultrasonically clean with deionized water for 15 min, and ultrasonically clean with isopropanol for 15 min. After drying, perform ultraviolet-ozone surface treatment for 5 min to obtain a substrate containing an anode.

[0117] S1.2 Under normal temperature and pressure air environment, compound A (purchased from Baytron, product model P-VP-AI4083) and compound B (synthesis method referred to Chinese patent application CN101878192A) are mixed at a mass ratio of compound A: compound B of 1:1 to obtain a mixture. The mixture is then spin-coated on the side of the anode away from the substrate in step S1.1, and then placed at a constant temperature of 150°C for 25 min to obtain a hole functional layer.

[0118] S1.3 Under a nitrogen atmosphere at normal temperature and pressure, spin-coat the side of the hole functional layer away from the anode in step S1.2 with a concentration of 25 mg / mL of Cd. 0.10 Zn 0.9 Se / Cd 0.1 Zn 0.9 Se / ZnSe / ZnS quantum dots in n-octane solution were then subjected to constant temperature heat treatment at 60℃ for 5 min to obtain the luminescent layer.

[0119] S1.4 Under a nitrogen atmosphere at normal temperature and pressure, a nano ZnO-ethanol solution with a concentration of 30 mg / mL is spin-coated on the side of the light-emitting layer away from the hole-functional layer in step S1.3, and then heat-treated at 80°C for 30 min to obtain an electron transport layer.

[0120] S1.5. In step S1.4, Ag is deposited on the side of the electron transport layer away from the light-emitting layer to obtain a cathode, and then the cathode is packaged to obtain a light-emitting device.

[0121] Example 2

[0122] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device of this embodiment is only that the mass ratio of compound A to compound B in the hole functional layer is 1:4.

[0123] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure according to the mass ratio of compound A: compound B of 1:4 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0124] Example 3

[0125] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the only distinguishing technical feature of the light-emitting device of this embodiment is that the mass ratio of compound A to compound B in the hole functional layer is 1:5.

[0126] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0127] Example 4

[0128] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the only distinguishing technical feature of the light-emitting device of this embodiment is that the mass ratio of compound A to compound B in the hole functional layer is 1:5.5.

[0129] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5.5 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0130] Example 5

[0131] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device of this embodiment is only that the mass ratio of compound A to compound B in the hole functional layer is 1:6.

[0132] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:6 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0133] Example 6

[0134] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the only distinguishing technical feature of the light-emitting device in this embodiment is that the mass ratio of compound A to compound B in the hole functional layer is 1:8.

[0135] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced with "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:8 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0136] Example 7

[0137] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the only distinguishing technical feature of the light-emitting device in this embodiment is that the mass ratio of compound A to compound B in the hole functional layer is 1:10.

[0138] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of 1:10 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0139] Example 8

[0140] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device in this embodiment is only that: in the hole functional layer, the mass ratio of compound A to compound B is 1:5, and compound B has the structure shown in formula (1.2):

[0141]

[0142] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0143] Example 9

[0144] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device in this embodiment is only that: in the hole functional layer, the mass ratio of compound A to compound B is 1:5.5, and compound B has the structure shown in formula (1.3):

[0145]

[0146] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5.5 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0147] Example 10

[0148] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device in this embodiment is only that: in the hole functional layer, the mass ratio of compound A to compound B is 1:5, and compound B has the structure shown in formula (1.4):

[0149]

[0150] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0151] Example 11

[0152] This embodiment provides a light-emitting device and its preparation method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device in this embodiment is only that: in the hole functional layer, the mass ratio of compound A to compound B is 1:5.8, and compound B has the structure shown in formula (1.5):

[0153]

[0154] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced by "mixing compound A and compound B in an air environment at room temperature and pressure at a mass ratio of compound A: compound B of 1:5.8 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it under constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0155] Example 12

[0156] This embodiment provides a light-emitting device and its fabrication method. Compared with the light-emitting device of Embodiment 1, the distinguishing technical feature of the light-emitting device in this embodiment is only that: in the hole functional layer, the mass ratio of compound A to compound B is 1:5.6, and compound B has the structure shown in formula (1.6):

[0157]

[0158] Compared to the preparation method of Example 1, the only difference in the preparation method of this example is that step S1.2 is replaced with "mixing compound A and compound B in an air environment at room temperature and pressure according to the mass ratio of compound A: compound B of 1:5.6 to obtain a mixture, spin-coating the mixture on the side of the anode away from the substrate in step S1.1, and then placing it in a constant temperature heat treatment at 150°C for 25 minutes to obtain a hole functional layer".

[0159] Comparative Example 1

[0160] This comparative example provides a light-emitting device and its preparation method. Compared with the light-emitting device of Example 1, the only difference of the light-emitting device of this comparative example is that the material of the hole functional layer is compound A (PEDOT:PSS).

[0161] Compared with the preparation method of Example 1, the only difference in the preparation method of this comparative example is that step S1.2 is replaced with "in an air environment at room temperature and pressure, compound A is spin-coated on the side of the anode away from the substrate in step S1.1, and then placed at a constant temperature of 150°C for 25 minutes to obtain a hole functional layer".

[0162] Comparative Example 2

[0163] This comparative example provides a light-emitting device and its fabrication method. Compared with the light-emitting device of Example 1, the only difference of the light-emitting device in this comparative example is that the hole functional layer is composed of a hole injection layer and a hole transport layer stacked together. The material of the hole injection layer is compound A (PEDOT:PSS), and the material of the hole transport layer is poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) (abbreviated as TFB, CAS number 220797-16-0). The hole injection layer is disposed between the anode and the light-emitting layer, and the hole transport layer is disposed between the hole injection layer and the light-emitting layer. The thickness of the hole injection layer is 20 nm, and the thickness of the hole transport layer is 20 nm.

[0164] Compared to the preparation method of Example 1, the only difference in the preparation method of this comparative example is that step S1.2 is replaced with "in an air environment at room temperature and pressure, compound A is spin-coated on the side of the anode away from the substrate in step S1.1, and then placed at a constant temperature of 150°C for 30 min to obtain a hole injection layer; then, a TFB-chlorobenzene solution with a concentration of 8 mg / mL is spin-coated on the side of the hole injection layer away from the anode, and then placed at a constant temperature of 180°C for 30 min to obtain a hole transport layer".

[0165] Experimental Example

[0166] The performance of the light-emitting devices of Examples 1 to 12, as well as Comparative Examples 1 and 2, was tested. The test items included: the light-emitting devices at 2mA / cm 2 The time (T95,h) required for brightness to decay from 100% to 95% at a given current density and the maximum external quantum efficiency (EQE) maxThe voltage, current, brightness, and emission spectrum of each light-emitting device were measured using a Fostar FPD optical property measurement device (an efficiency testing system built by LabVIEW-controlled QE-PRO spectrometer, Keithley 2400, and Keithley 6485). Key parameters such as external quantum dot efficiency and power efficiency were obtained through calculation. The T95 of each light-emitting device was obtained by using a lifetime testing device.

[0167] In addition, the hole mobility of the hole functional layer in the light-emitting devices of Examples 1 to 12, Comparative Examples 1 and 2 was tested / (×10) -6 cm 2 The structured device for hole mobility testing consists of an anode, a hole functional layer, a light-emitting layer, and a cathode arranged sequentially (the materials and thicknesses of each layer are as described in the corresponding embodiments and comparative examples; that is, compared to the light-emitting devices of each embodiment, Comparative Example 1, and Comparative Example 2, the structured device for hole mobility testing here only omits the electron transport layer). The specific testing method is as follows: the current density-voltage curve of the corresponding structured device is tested using a Fostec FPD optical characteristic measurement device (e.g., / V·s). Figure 6 and Figure 7 As shown), the space charge confined current (SCLC) region in the current density-voltage curve is obtained, and then the formula J = (9 / 8)ε is used. r ε0μ e V 2 / d 3 The hole mobility was calculated, where J represents the current density in mA / cm². 2 ;ε r ε₀ represents the relative permittivity; μ₀ represents the vacuum permittivity; μ₀ represents the relative permittivity. e This represents hole mobility, expressed in cm. 2 / V·s; V represents the driving voltage in V; d represents the film thickness in m. It should be noted that although the structural device used for hole mobility testing is not a complete light-emitting device, this is done for ease of understanding. Figure 6 and Figure 7 Examples 1 to 12, and Comparative Examples 1 and 2 are still referred to as Examples 1 to 12.

[0168] Furthermore, the electron mobility of the electron transport layer in the light-emitting devices of Examples 1 to 12, and Comparative Examples 1 and 2, was tested. The structural device for electron mobility testing consisted of an anode, a light-emitting layer, an electron transport layer, and a cathode arranged sequentially (the materials and thicknesses of each layer were the same as in the corresponding examples and comparative examples; that is, compared to the light-emitting devices of each example, Comparative Example 1, and Comparative Example 2, the structural device for hole mobility testing here only omitted the hole functional layer). The specific testing method was the same as that for hole mobility testing. It should be noted that under this testing method, the measured electron mobility of each example, Comparative Example 1, and Comparative Example 2 was actually the same. Figure 8 As shown, the electron mobility is approximately 145.9 × 10⁻⁶. -5 cm 2 / V·s.

[0169] The performance test results are detailed in Table 1 below:

[0170] Table 1 shows the performance test results of the light-emitting devices in Examples 1 to 12, and Comparative Examples 1 and 2.

[0171]

[0172] From Table 1, Figure 6 and Figure 7 It can be seen that the light-emitting devices of Examples 1 to 12 have significant advantages in overall performance. Taking Example 4 as an example, the hole mobility of the light-emitting device in Example 4 is 3.3 times that of the light-emitting device in Example 1, and 2.1 times that of the light-emitting device in Example 2; the EQE of the light-emitting device in Example 4... max EQE of the light-emitting device in Comparative Example 1 max 6.7 times that of the optical device in Comparative Example 2, and the EQE of the optical device. max The T95 of the light-emitting device in Example 4 is 4.5 times that of the light-emitting device in Comparative Example 1, and 3.6 times that of the light-emitting device in Comparative Example 2, and 2.7 times that of the light-emitting device in Comparative Example 2. The difference between electron mobility and hole mobility in the light-emitting devices of Examples 1 to 12 is significantly smaller than that in Comparative Example 1 and Comparative Example 2. Among them, the difference between electron mobility and hole mobility in the light-emitting device of Example 4 is the smallest. Therefore, the photoelectric performance and lifespan of the light-emitting devices of Examples 1 to 12 are better than those of Comparative Example 1 and Comparative Example 2.

[0173] The experimental results of this example demonstrate that using compounds A and B as the materials for the hole functional layer, based on the self-assembly of compounds A and B to form a stable ordered structure, and the aggregation of compound A on top of compound B, the hole functional layer is equivalent to a two-layer structure consisting of a compound A layer (equivalent to a "hole injection layer") and a compound B layer (equivalent to a "hole transport layer"). The resulting low potential barrier between the compound A and compound B layers effectively improves hole mobility, thereby promoting hole-electron transport balance, and ultimately improving the luminous efficiency of the light-emitting device, which is beneficial for extending the lifespan of the light-emitting device. Furthermore, the hole functional layer in Comparative Example 2 consists of a stacked hole injection layer and a hole transport layer. The preparation method of the hole functional layer requires the sequential fabrication of the hole injection layer and the hole transport layer, which not only increases the complexity and cost of the process but also results in a high potential barrier between the hole injection layer and the hole transport layer, thus limiting the promoting effect on hole injection. Therefore, the overall performance of the light-emitting device in Comparative Example 2 is inferior to that of the light-emitting devices in Examples 1 to 12.

[0174] Furthermore, among the light-emitting devices of Examples 1 to 7, the overall performance of the light-emitting devices of Examples 3 to 6 is superior to that of Examples 1, 2, and 7. This indicates that when the mass ratio of compound A to compound B in the hole functional layer is 1:(5-8), compounds A and B are more likely to self-assemble into a stable ordered structure, which is beneficial for further improving the photoelectric performance and lifespan of the light-emitting device.

[0175] The foregoing has provided a detailed description of a light-emitting device, a method for fabricating the light-emitting device, and a display device according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A light-emitting device, characterized in that, include: anode; The cathode is disposed opposite to the anode; A light-emitting layer is disposed between the anode and the cathode; as well as A hole-functional layer is disposed between the anode and the light-emitting layer; The hole functional layer is made of compound A and compound B, wherein compound A is poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), and compound B has the structure shown in general formula (I): (Ⅰ) In general formula (I), R1 and R2 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, groups containing aryl groups, groups containing aryloxy groups, and groups containing -CO-R s Groups or containing -CO-OR t The group, wherein R s and R t The groups are selected independently from each other, either from alkyl groups having 1 to 10 carbon atoms or from aryl groups; R3 to R7 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, cyano, nitro or halogen atoms. At least one of R1 to R7 is selected from a group containing a perfluoroalkyl group having 1 to 10 carbon atoms.

2. The light-emitting device according to claim 1, characterized in that, R1 and R2 are independently selected from groups comprising cycloalkyl groups having 3 to 6 carbon atoms, groups comprising perfluoroalkyl groups having 1 to 10 carbon atoms, groups comprising phenyl groups, groups comprising phenoxy groups, and groups comprising -CO-R groups. s Groups or containing -CO-OR t The group, wherein R s Selected from at least one of haloalkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, or phenyl groups, R t It is selected from at least one of a haloalkyl or phenyl group having 1 to 10 carbon atoms.

3. The light-emitting device according to claim 2, characterized in that, R1 or R2 is selected from phenyl groups containing perfluoroalkyl groups.

4. The light-emitting device according to claim 1, characterized in that, R3 to R7 are independently selected from at least one of cycloalkyl groups having 3 to 6 carbon atoms or perfluoroalkyl groups having 1 to 10 carbon atoms.

5. The light-emitting device according to claim 1, characterized in that, R3 to R7 are selected from alkyl groups having 3 to 6 carbon atoms, and at least one of R3 to R7 is a perfluoroalkyl group having 1 to 4 carbon atoms.

6. The light-emitting device according to claim 1, characterized in that, Compound B is selected from: 、 、 , , or At least one of them.

7. The light-emitting device according to claim 1, characterized in that, In the hole-functional layer, the mass ratio of compound A to compound B is 1:(1 to 10).

8. The light-emitting device according to claim 7, characterized in that, The mass ratio of compound A to compound B is 1:(5-8).

9. The light-emitting device according to any one of claims 1 to 8, characterized in that, The material of the light-emitting layer includes organic light-emitting materials or quantum dots; The organic light-emitting material is selected from at least one of diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent material emitting blue light, TTPA fluorescent material emitting green light, TBRb fluorescent material emitting orange light, and DBP fluorescent material emitting red light. The quantum dots are selected from at least one of group II-VI, III-V, IV-VI, and I-III-VI compounds, wherein the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and CdZnTe. At least one of CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and Ga NP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAl NAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPA The compounds are selected from at least one of SnS and InAlPSb, wherein the group IV-VI compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, and the group I-III-VI compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.

10. The light-emitting device according to any one of claims 1 to 8, characterized in that, The light-emitting device further includes an electron transport layer disposed between the cathode and the light-emitting layer. The electron transport layer is made of nano-metal oxide, which is selected from at least one of ZnO, TiO2, SnO2, Ta2O3, ZrO2, TiLiO, ZnGaO, ZnAlO, ZnMgO, ZnSnO, ZnLiO, InSnO, and AlZnO.

11. A method for fabricating a light-emitting device, characterized in that, The preparation method includes the following steps: A mixture comprising compound A and compound B is provided; An anode is provided, the mixture is applied to one side of the anode, and then dried to form a film to obtain a hole-functionalized layer; A light-emitting layer is formed on the side of the hole-functional layer away from the anode; A cathode is formed on the side of the light-emitting layer away from the hole-functional layer; Alternatively, the preparation method includes the following steps: A cathode is provided, and a light-emitting layer is formed on one side of the cathode; A mixture comprising compound A and compound B is provided, the mixture is applied to one side of the cathode, and then dried to form a film to obtain a hole-functional layer; An anode is formed on the side of the hole functional layer away from the light-emitting layer; Wherein, compound A is poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), and compound B has the structure shown in general formula (I): (Ⅰ) In general formula (I), R1 and R2 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, groups containing aryl groups, groups containing aryloxy groups, and groups containing -CO-R s Groups or containing -CO-OR t The group, wherein R s and R t The groups are selected independently from each other, either from alkyl groups having 1 to 10 carbon atoms or from aryl groups; R3 to R7 are independently selected from hydrogen atoms, groups containing alkyl groups having 1 to 10 carbon atoms, groups containing alkylthio groups having 1 to 8 carbon atoms, groups containing alkoxy groups having 1 to 8 carbon atoms, cyano, nitro or halogen atoms. At least one of R1 to R7 is selected from a group containing a perfluoroalkyl group having 1 to 10 carbon atoms.

12. The preparation method according to claim 11, characterized in that, In the mixture, the mass ratio of compound A to compound B is 1:(1 to 10).

13. The preparation method according to claim 12, characterized in that, The mass ratio of compound A to compound B is 1:(5-8).

14. A display device, characterized in that, The display device includes a light-emitting device as described in any one of claims 1 to 10 or a light-emitting device prepared by the preparation method described in any one of claims 11 to 13.

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