Light-emitting device and preparation method therefor, and display panel

Abstract

A light-emitting device, comprising: a substrate, and an anode, a light-emitting layer, an electron transport layer and a cathode which are stacked on one side of the substrate, wherein the material of the electron transport layer comprises a metal oxide; the electron transport layer further contains hydrogen, the forms of existence of hydrogen in the electron transport layer including: substitutional hydrogen bonded to atoms in the metal oxide, and interstitial hydrogen existing in a free state in the metal oxide; and in the electron transport layer, the ratio of the number of atoms of substitutional hydrogen to the number of atoms of hydrogen is greater than or equal to 10%.

Description

Light-emitting device, preparation method thereof and display panel TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular to a light-emitting device, a preparation method thereof and a display panel. BACKGROUND

[0002] As a new type of light-emitting material, quantum dots (QDs) have the advantages of high light color purity, high light-emitting quantum efficiency, adjustable light-emitting color, long service life, etc., and have become a research hotspot of new light-emitting diode (LED) light-emitting materials. Therefore, quantum dot light-emitting diode (QLED) using quantum dot material as a light-emitting layer has become a main direction of research on new display devices.

[0003] SUMMARY

[0004] In one aspect, a light-emitting device is provided, which includes a substrate and, stacked on one side of the substrate, an anode, a light-emitting layer, an electron transport layer, and a cathode, the material of the electron transport layer including a metal oxide; wherein the electron transport layer further includes a hydrogen element, the existence form of the hydrogen element in the electron transport layer including substitution hydrogen bonded with atoms in the metal oxide and interstitial hydrogen in a free state in the metal oxide; in the electron transport layer, the ratio of the number of atoms of the substitution hydrogen to the number of atoms of the hydrogen element is greater than or equal to 10%.

[0005] In some embodiments, in the electron transport layer, the ratio of the number of atoms of the substitution hydrogen to the number of atoms of the hydrogen element ranges from 25% to 35%.

[0006] In some embodiments, the electron transport layer is a single layer, and the concentration of the number of atoms of the hydrogen element in the electron transport layer ranges from 10 14 cm -3 ~ 10 16 cm -3 .

[0007] In some embodiments, the electron transport layer includes a first sub-layer and a second sub-layer stacked together, the material of the first sub-layer and the material of the second sub-layer being at least partially different; and the concentration of the number of atoms of the hydrogen element in the electron transport layer ranges from 10 18 cm -3 ~ 10 22 cm -3 .

[0008] In some embodiments, the electron transport layer further comprises: auxiliary atoms, the auxiliary atoms having a relative atomic mass greater than or equal to 14.

[0009] In some embodiments, the auxiliary atoms comprise at least one of argon atoms, nitrogen atoms, and xenon atoms.

[0010] In some embodiments, the auxiliary atoms exist in the form of: substitution auxiliary atoms bonded with atoms in the metal oxide and interstitial auxiliary atoms in a free state in the metal oxide.

[0011] In some embodiments, in the electron transport layer, the number of atoms of the interstitial auxiliary atoms is greater than the number of atoms of the substitution auxiliary atoms.

[0012] In some embodiments, the ratio of the number of atoms of the substitution auxiliary atoms to the sum of the number of atoms of the substitution auxiliary atoms and the interstitial auxiliary atoms ranges from 20% to 35%.

[0013] In some embodiments, the material of the light-emitting layer comprises quantum dot light-emitting material.

[0014] In some embodiments, the material of the electron transport layer comprises metal oxide nanoparticles or metal oxide films.

[0015] In another aspect, a method for manufacturing a light-emitting device is provided, the method comprising: providing a substrate; forming, on one side of the substrate, a stack of an anode, a light-emitting layer, an electron transport layer, and a cathode to obtain a light-emitting device; wherein the material of the electron transport layer comprises a metal oxide; the electron transport layer further comprises hydrogen elements, the hydrogen elements existing in the electron transport layer in the form of: substitution hydrogen bonded with atoms in the metal oxide and interstitial hydrogen in a free state in the metal oxide; in the electron transport layer, the ratio of the number of atoms of the substitution hydrogen to the number of atoms of the hydrogen elements is greater than or equal to 10%.

[0016] In some embodiments, the forming, on one side of the substrate, a stack of an anode, a light-emitting layer, an electron transport layer, and a cathode to obtain a light-emitting device comprises: forming, on one side of the substrate, a stack of an anode, a light-emitting layer, an initial electron transport layer, and a cathode to obtain an initial light-emitting device; treating the initial light-emitting device under the condition of hydrogen gas and auxiliary gas to form the initial electron transport layer into an electron transport layer to obtain a light-emitting device; wherein the auxiliary gas has a relative molecular mass or a relative atomic mass greater than or equal to 28.

[0017] In some embodiments, the auxiliary gas comprises at least one of argon gas, nitrogen gas, and xenon gas.

[0018] In some embodiments, forming the initial electron transport layer comprises: forming the initial electron transport layer by using a spin coating method; wherein a ratio of a volume of the auxiliary gas to a volume of the hydrogen gas ranges from 100:60 to 100:2.

[0019] In some embodiments, forming the initial electron transport layer comprises: forming the initial electron transport layer by using a radio frequency magnetron sputtering method; wherein a ratio of a volume of the auxiliary gas to a volume of the hydrogen gas ranges from 100:60 to 100:10.

[0020] In some embodiments, forming the initial electron transport layer comprises: forming a stacked initial first sub-layer and an initial second sub-layer, a material of the initial first sub-layer and a material of the initial second sub-layer being at least partially different; processing the initial light emitting device under conditions of hydrogen gas and auxiliary gas, the initial first sub-layer forming a first sub-layer, the initial second sub-layer forming a second sub-layer, forming an electron transport layer comprising the first sub-layer and the second sub-layer, to obtain a light emitting device; wherein a ratio of a volume of the auxiliary gas to a volume of the hydrogen gas ranges from 100:60 to 100:4.

[0021] In some embodiments, the processing the initial light emitting device comprises at least one of the following: plasma bombardment, photoionization, and field ionization.

[0022] In another aspect, a display panel is provided, comprising: the light emitting device according to any one of the above embodiments; the display panel further comprises: a pixel driving circuit, configured to drive the light emitting device to emit light. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present disclosure, the following will briefly introduce the drawings needed to be used in some embodiments of the present disclosure. Obviously, the drawings described in the following description are only some drawings of some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art according to these drawings. In addition, the drawings described in the following description can be regarded as schematic diagrams, and are not limited to the actual size, actual process, actual time sequence, etc. of the product involved in the embodiments of the present disclosure.

[0024] FIG. 1 is a structural diagram of a display device according to some embodiments of the present disclosure;

[0025] FIG. 2 is a structural diagram of a display panel according to some embodiments of the present disclosure;

[0026] FIG. 3 is a structural diagram of a light emitting device according to some embodiments;

[0027] FIG. 4 is a structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0028] FIG. 5 is another structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0029] FIG. 6 is another structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0030] FIG. 7 is a flow chart of a method for manufacturing a light emitting device according to some embodiments of the present disclosure;

[0031] FIGS. 8 and 9 are structural diagrams of respective steps of a method for manufacturing a light emitting device according to some embodiments of the present disclosure;

[0032] FIG. 10 is a graph of a luminance decay curve of a light emitting device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0033] The technical solutions in some embodiments of the present disclosure will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments provided in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0034] Unless otherwise required by context, the term “comprise” and other forms of the term “comprise”, such as “comprises” and “comprising”, and the like, are used in an open, inclusive and non-limiting sense, that is, as “including, but not limited to”. In the description of the specification, the terms “one embodiment”, “some embodiments”, “exemplary embodiments”, “example”, “specific example” or “some examples” are intended to mean that a particular feature, structure, material or characteristic included in at least one embodiment or example of the present disclosure. The illustrative representation of the above terms does not necessarily mean the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner.

[0035] Hereinafter, the terms “first” and “second” are used only for descriptive purposes, and cannot be understood to indicate or imply relative importance or implicitly indicate the number of indicated technical features. Therefore, the features defined with “first” and “second” can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of “a plurality of” is two or more.

[0036] In describing some embodiments, "coupled" and "connected," along with their derivatives, can be used. It should be understood that these terms are not intended as synonyms for each other. Rather, "connected" can be used to indicate that two or more elements are in direct physical or electrical contact with each other. "Coupled" can be used to indicate that two or more elements are in either physical or electrical contact with each other, even at a distance. As will be apparent, "a" or "an" can be used herein to refer to one or more than one (i.e., to "one or more") of the referenced material or object. The disclosure of an embodiment herein does not necessarily exclude other embodiments from the scope of the disclosure.

[0037] "at least one of A, B, and C" has the same meaning as "at least one of A, B, or C" and includes the following combinations: only A, only B, only C, A and B, A and C, B and C, and A and B and C.

[0038] "A and / or B" includes the following combinations: A alone, B alone, and A and B together.

[0039] As used herein, "about," "approximately," or "around" includes the recited value and the average value within an acceptable range of deviation from the recited value, as determined by one of ordinary skill in the art considering the measurement in question and the error intended to be introduced by the particular quantity measured (i.e., the limitations of the measurement system).

[0040] As used herein, "parallel," "perpendicular," and "equal" include the recited condition and conditions that approximate the recited condition, the approximation being within an acceptable range of deviation, as determined by one of ordinary skill in the art considering the measurement in question and the error intended to be introduced by the particular quantity measured (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and near parallel, where near parallel can be within an acceptable deviation range of, for example, 5°; "perpendicular" includes absolute perpendicular and near perpendicular, where near perpendicular can also be within an acceptable deviation range of, for example, 5°. "Equal" includes absolute equality and near equality, where near equality can be within an acceptable deviation range of, for example, less than or equal to 5% of either of the two quantities being compared.

[0041] It should be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers can also be present.

[0042] Exemplary embodiments are described herein with reference to cross-sectional and / or plan view illustrations that are schematic illustrations of idealized embodiments. Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etched region illustrated as a rectangle will, typically, have jagged edges. Thus, the regions illustrated in the figures are schematic and not drawn to scale. The same should be understood with regard to angles, etc. as illustrated in the figures.

[0043] Some embodiments of the present disclosure provide a display device 1000, which can be any device that displays whether it is in motion (e.g., video) or stationary (e.g., still images) and whether it is in text or image. More specifically, it is contemplated that the embodiments can be implemented in or in association with a variety of electronic devices such as, but not limited to, mobile telephones (e.g., cell phones), wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, auto displays (e.g., odometer display, etc.), cockpit controls and / or displays, camera view displays (e.g., display of a rear view camera in a vehicle), electronic photographs, electronic billboards or signs, projections, architectural structures, packaging, and aesthetic structures (e.g., display of images on a piece of jewelry), and the like. FIG. 1 illustrates a display device 1000 in the form of a mobile telephone.

[0044] Exemplarily, the display device 1000 can be an electroluminescent display device or a photoluminescent display device. In the case that the display device 1000 is an electroluminescent display device, the electroluminescent display device can be an organic electroluminescent display device (OLED) or a quantum dot electroluminescent display device (QLED). In the case that the display device 1000 is a photoluminescent display device, the photoluminescent display device can be a quantum dot photoluminescent display device. Hereinafter, some embodiments of the present disclosure are illustratively described with the display device 1000 as a QLED display device, but embodiments of the present disclosure include but are not limited to this, and any other display device can also be considered as long as the same technical idea is applied.

[0045] Please continue to refer to FIG. 1, the display device 1000 described above comprises a display panel 100.

[0046] As shown in FIG. 2, the display panel 100 includes the light emitting device 10 and a pixel driving circuit 20 for driving the light emitting device 10 to emit light.

[0047] In some examples, as shown in FIG. 3, the light emitting device 10 includes, stacked on one side of a substrate 101, an anode 102, a light emitting layer 103, an electron transport layer 104, and a cathode 105.

[0048] Exemplarily, the material of the substrate 101 can be a rigid material, such as glass, or a flexible material, such as polyimide (PI) or polyethylene glycol terephthalate (PET).

[0049] In some examples, the anode 102 can be a transparent electrode, in which case the material of the anode 102 can be indium tin oxide (ITO) or fluorine-doped tin oxide conductive glass (FTO), or a conductive polymer, such as polyaniline (PANI), polycarbazole (PZ), polythiophene (PTh), or polypyrrole (PPy).

[0050] Exemplarily, the cathode 105 can be made of a material with a low work function, so that electrons of the cathode 105 can be more easily injected into an adjacent film layer (such as the electron transport layer 104 described in detail below), so that the electrons generated by the cathode 105 can be effectively migrated into the light emitting layer 103 under the drive of an electric field, and then recombine with holes generated by the anode 102 to emit light.

[0051] In some examples, the material of the cathode 105 can be a metal material, a metal oxide, or a metal alloy, etc. The metal material can be, for example, aluminum (Al), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium (Li), potassium (K), sodium (Na), tin (Sn), titanium (Ti), lead (Pb), samarium (Sm), or yttrium (Y), etc. The metal oxide can be, for example, indium tin oxide (ITO) or indium zinc oxide (IZO), etc. The metal alloy can be, for example, magnesium-silver alloy (Mg:Ag), ytterbium-gold alloy (Yb:Au), ytterbium-silver alloy (Yb:Ag), lithium-aluminum alloy (Li:Al), or lithium-calcium-magnesium alloy (Li:Ca:Al), etc. Alternatively, the material of the cathode 105 can be a laminated material, such as magnesium / aluminum (Mg / Al), magnesium / silver (Mg / Ag), aluminum / silver (Al / Ag), aluminum / gold (Al / Au), ytterbium / gold (Yb / Au), ytterbium / silver (Yb / Ag), calcium / magnesium (Ca / Mg), calcium / silver (Ca / Ag), or barium / silver (Ba / Ag), etc.

[0052] Through the circuit connected by the anode 102 and the cathode 105, holes are injected into the light-emitting layer 103 by the anode 102, and electrons are injected into the light-emitting layer 103 by the cathode 105. The formed electrons and holes form excitons in the light-emitting layer 103. The excitons return to the ground state through radiative transition, and emit photons.

[0053] In some embodiments, as shown in FIG. 3, the electron transport layer 104 can have defects, such as, for example, metal vacancies, metal anti-sites, metal interstitials, oxygen interstitials, oxygen anti-sites, and oxygen vacancies. These defects can be generated, for example, during the growth of the electron transport material, or generated after the breaking of bonds caused by electric field and heat during the operation of the light-emitting device 10. Among them, the oxygen vacancy is the oxygen element in the lattice of the metal oxide that detaches, resulting in a lack of oxygen and forming a vacancy.

[0054] The hydrogen treatment process is used to treat the electron transport layer 104. The hydrogen element 11 can enter the defects in the electron transport layer 104. The hydrogen element 11, as a shallow donor, can enhance the conductivity of the electron transport layer 104, so that the performance of the light-emitting device 10 is improved. The improved performance of the light-emitting device 10 can include, for example, at least one of efficiency, conductivity, and operating life.

[0055] For a clearer illustration, the state of the hydrogen element 11 in the electron transport layer 104 is exemplarily described below by taking ZnO as the material of the electron transport layer 104. When the material of the electron transport layer 104 is ZnO, the hydrogen element 11 in the electron transport layer 104 can exist in a free form in the electron transport layer 104, or can enter the crystal lattice between ZnO and be connected by a chemical bond to form Zn-H-O or Zn-O-H, etc., so that the hydrogen element 11 constitutes part of the electron transport layer 104; in other words, the hydrogen element 11 can act as a shallow donor in the ZnO material, so that the conductivity of the ZnO material is improved.

[0056] Herein, the hydrogen element 11 existing in a free form in the electron transport layer 104 can be referred to as interstitial hydrogen 11a, and the hydrogen element 11 entering the crystal lattice between ZnO and being connected by a chemical bond can be referred to as substitution hydrogen 11b. The shallow donor refers to the hydrogen element 11 providing an electron by delocalization to improve the conductivity of the electron transport layer 104.

[0057] According to theoretical calculation, the diffusion energy barrier of the substitution hydrogen 11b is greater than that of the interstitial hydrogen 11a, and compared with the interstitial hydrogen 11a, the substitution hydrogen 11b with a greater diffusion energy barrier can exist more stably in the electron transport layer 104, so that the performance reliability of the light-emitting device 10 is stronger.

[0058] It should be noted that the diffusion energy barrier refers to the potential barrier that needs to be overcome by the hydrogen element 11 to leave the original position.

[0059] However, the hydrogen element 11 in the electron transport layer 104 mostly exists in the form of the interstitial hydrogen 11a. For example, in the electron transport layer 104, the ratio of the number of atoms of the substitution hydrogen 11b to the number of atoms of the hydrogen element 11 is less than 10%. The lower diffusion energy barrier of the interstitial hydrogen 11a leads to poor reliability of the hydrogen treatment process, so that the performance stability of the light-emitting device 10 needs to be further improved.

[0060] Based on this, as shown in FIG. 4, an embodiment of the present disclosure provides a light-emitting device 10, which comprises, from the side of a substrate 101, an anode 102, a light-emitting layer 103, an electron transport layer 104, and a cathode 105.

[0061] The introduction of the substrate 101, the anode 102, and the cathode 105 can refer to the above description, and will not be described here again.

[0062] Exemplarily, the material of the light-emitting layer 103 comprises quantum dot light-emitting material. For example, the quantum dot light-emitting material comprises at least one of CdS, CdSe, CdTe, ZnSe, InP, PbS, CuInS2, ZnO, CsPbCl3, CsPbBr3, CsPhI3, CdS / ZnS, CdSe / ZnS, ZnSe, InP / ZnS, PbS / ZnS, InAs, InGaAs, InGaN, GaNk, ZnTe, Si, Ge and C, etc. Among them, the quantum dot light-emitting material is CdS / ZnS, CdSe / ZnS, InP / ZnS and PbS / ZnS, which means that the quantum dot light-emitting material is core-shell structure, in which one material is the material of the core and the other is the material of the shell. For example, the quantum dot light-emitting material is CdS / ZnS, which means that the material of the core of the quantum dot is CdS and the material of the shell is ZnS.

[0063] In other embodiments, the quantum dot light-emitting material can be other nanoscale materials, such as nanorods, nanosheets, etc. The composition of other nanoscale materials can comprise at least one of CdS, CdSe, CdTe, ZnSe, InP, PbS, CuInS2, ZnO, CsPbCl3, CsPbBr3, CsPhI3, CdS / ZnS, CdSe / ZnS, ZnSe, InP / ZnS, PbS / ZnS, InAs, InGaAs, InGaN, GaNk, ZnTe, Si, Ge and C, etc.

[0064] As shown in FIG. 4, the material of the electron transport layer 104 comprises metal oxide, and the electron transport layer 104 further comprises hydrogen element 11, the existence form of the hydrogen element 11 in the electron transport layer 104 comprises substitution hydrogen 11b bonded with atoms in the metal oxide and interstitial hydrogen 11a in a free state in the metal oxide, and the ratio of the number of atoms of the substitution hydrogen 11b to the number of atoms of the hydrogen element 11 in the electron transport layer 104 is greater than or equal to 10%.

[0065] Exemplarily, the metal oxide comprises at least one of zinc oxide, magnesium oxide, magnesium zinc oxide and tin oxide.

[0066] Exemplarily, in the infrared spectrum of the electron transport layer 104, the absorption peak area in the wave band range of 2400 nm-2700 nm, according to the formula y1 = [(x1-15.42) x 10 11 ] / 2555.12, the number of atoms of the substitution hydrogen 11b is calculated, wherein x1 represents the absorption peak area in the wave band range of 2400 nm-2700 nm, and y1 represents the number of atoms of the substitution hydrogen 11b.

[0067] For example, the electron transport layer 104 is heated to 800℃ in a sealed environment, and a gas chromatography test is performed to obtain a chromatographic peak of hydrogen element 11 and a chromatographic area of hydrogen element 11. According to the formula y2=x2 / (5.3x10 -18 ), the concentration of the atomic number of hydrogen element 11 is obtained; according to the formula z=y2x(8x10 -9 ), the atomic number of hydrogen element 11 is calculated; wherein x2 represents the chromatographic peak area of hydrogen element 11, y2 represents the concentration of the atomic number of hydrogen element 11, and z represents the atomic number of hydrogen element 11.

[0068] For example, in photoelectron spectroscopy, the characteristic peak of substitutional hydrogen is in the range of 529.9eV-532.1eV. In ultraviolet spectroscopy, the characteristic peaks of interstitial hydrogen 11a include 410.2nm, 434nm, 486.1nm and 656.3nm.

[0069] From the above introduction of interstitial hydrogen 11a and substitutional hydrogen 11b, it can be seen that the diffusion energy barrier of substitutional hydrogen 11b is greater than that of interstitial hydrogen 11a. Compared with interstitial hydrogen 11a, substitutional hydrogen 11b with a larger diffusion energy barrier can exist more stably in the electron transport layer 104, so that the performance reliability of the light-emitting device 10 is stronger.

[0070] In some examples, the difference between the diffusion energy barrier of substitutional hydrogen 11b and the diffusion energy barrier of interstitial hydrogen 11a is in the range of 1eV-1.3eV. For example, the difference between the diffusion energy barrier of substitutional hydrogen 11b and the diffusion energy barrier of interstitial hydrogen 11a is 1eV, 1.1eV, 1.2eV or 1.3eV, etc. without limitation here.

[0071] For example, the diffusion energy barrier of interstitial hydrogen 11a is 0.4eV-0.5eV, and the diffusion energy barrier of substitutional hydrogen 11b is 1.7eV, which is higher than that of interstitial hydrogen 11a.

[0072] By setting the ratio of the atomic number of substitutional hydrogen 11b to the atomic number of hydrogen element 11 in the electron transport layer 104 to be greater than or equal to 10%, it is ensured that there is a sufficient number of substitutional hydrogen 11b in the electron transport layer 104, so that hydrogen element 11 can exist more stably in the electron transport layer 104, so that the performance reliability of the light-emitting device 10 is stronger.

[0073] For example, how to increase the proportion of the atomic number of substitutional hydrogen 11b in the atomic number of hydrogen element 11 in the electron transport layer 104 is described in the subsequent introduction of the preparation method of the light-emitting device, which is not described here.

[0074] In some embodiments, as shown in FIG. 4, in the electron transport layer 104, the ratio of the number of atoms of the substituted hydrogen 11b to the number of atoms of the hydrogen element 11 ranges from 25% to 35%.

[0075] For example, in the electron transport layer 104, the ratio of the number of atoms of the substituted hydrogen 11b to the number of atoms of the hydrogen element 11 is 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, or 35%, and the like, which are not limited herein.

[0076] By setting the ratio of the number of atoms of the substituted hydrogen 11b to the number of atoms of the hydrogen element 11 in the electron transport layer 104 to range from 25% to 35%, the hydrogen element 11 can be more stably present in the electron transport layer 104, so that the performance reliability of the light-emitting device 10 is stronger.

[0077] In some embodiments, as shown in FIG. 4, the electron transport layer 104 is a single layer, and the concentration of the number of atoms of the hydrogen element 11 in the electron transport layer 104 ranges from 10 14 cm -3 to 10 16 cm -3 .

[0078] For example, the electron transport layer 104 is heated to 800°C in a closed environment, and gas chromatography testing is performed to obtain a chromatographic peak of the hydrogen element 11 and a chromatographic area of the hydrogen element 11, and the concentration of the number of atoms of the hydrogen element 11 is obtained according to the formula y2=x2 / (5.3x10 -18 ).

[0079] For example, as shown in FIG. 4, the electron transport layer 104 is a single layer structure, for example, the thickness d1 of the electron transport layer 104 ranges from 20 nm to 40 nm. The concentration of the number of atoms of the hydrogen element 11 in the electron transport layer 104 is 10 14 cm -3 , 10 15 cm -3 , or 10 16 cm -3 , and the like, which are not limited herein.

[0080] The preparation method of the light-emitting device provided by the embodiments of the present disclosure can achieve the purpose of the concentration of the number of atoms of the hydrogen element 11 in the electron transport layer 104 ranging from 10 14 cm -3 to 10 16 cm -3 , so that a sufficient number of substituted hydrogen 11b exists in the electron transport layer 104, so that the performance reliability of the light-emitting device 10 is stronger.

[0081] In some embodiments, as shown in FIG. 5, the electron transport layer 104 comprises: a first sub-layer 141 and a second sub-layer 142 stacked together, the material of the first sub-layer 141 and the material of the second sub-layer 142 are at least partially different; the concentration of the atomic number of the hydrogen element 11 in the electron transport layer 104 ranges from 10 18 cm -3 ~ 10 22 cm -3 .

[0082] For example, the first sub-layer 141 is located on the side of the second sub-layer 142 close to the substrate 101. The material of the first sub-layer 141 and the material of the second sub-layer 142 are independently selected from at least one of zinc oxide, magnesium oxide, magnesium zinc oxide and tin oxide, and the material of the first sub-layer 141 and the material of the second sub-layer 142 are at least partially different, for example, the material of the first sub-layer 141 is selected from zinc oxide, and the material of the second sub-layer 142 is selected from magnesium oxide.

[0083] For example, the thickness d2 of the first sub-layer 141 ranges from 15 nm to 20 nm, and the thickness d3 of the second sub-layer 142 ranges from 10 nm to 20 nm.

[0084] For example, the concentration of the atomic number of the hydrogen element 11 in the electron transport layer 104 is 10 18 cm -3 , 10 19 cm -3 , 10 20 cm -3 , 10 21 cm -3 or 10 22 cm -3 , etc., which are not limited herein.

[0085] When the electron transport layer 104 comprises: a first sub-layer 141 and a second sub-layer 142 stacked together, due to the interface barrier between the first sub-layer 141 and the second sub-layer 142, in order to ensure that the hydrogen element 11 can overcome the interface barrier and diffuse in the electron transport layer 104, therefore, the concentration of the atomic number of the hydrogen element 11 in the electron transport layer 104 ranges from 10 18 cm - 3 ~ 10 22 cm -3 .

[0086] In some embodiments, as shown in FIG. 4 and FIG. 5, the electron transport layer 104 further comprises: an auxiliary atom 14a, the relative atomic mass of the auxiliary atom 14a is greater than or equal to 14.

[0087] For example, in order to increase the number of atoms of the substituted hydrogen 11b in the electron transport layer 104, the light emitting device 10 is treated with the auxiliary gas and the hydrogen gas at the same time, and thus the auxiliary atom 14a is present in the electron transport layer 104. The content related to the formation of the auxiliary atom 14a can be referred to the description of the method of manufacturing the light emitting device, and thus will not be described herein.

[0088] For example, the auxiliary gas has a relative molecular mass or a relative atomic mass greater than or equal to 28. For example, the auxiliary gas includes at least one of argon, nitrogen, and xenon. The relative molecular mass of argon is 39.95, the relative atomic mass of an argon atom is 39.95, the relative molecular mass of nitrogen is 28, the relative atomic mass of a nitrogen atom is 14, and the relative molecular mass of xenon is 131.3, and the relative atomic mass of a xenon atom is 131.3.

[0089] For example, the auxiliary atom 14a is at least one of an argon atom, a nitrogen atom, and a xenon atom.

[0090] The auxiliary atom 14a can fill the defects in the electron transport layer 104, and thus the current density of the light emitting device 10 can be increased.

[0091] In some embodiments, as shown in FIGS. 4 and 5, the auxiliary atom 14a is present in the form of a substitution auxiliary atom bonded to an atom in the metal oxide and a gap auxiliary atom in a free state in the metal oxide.

[0092] For example, in the photoelectron spectroscopy, the characteristic peak of the substitution auxiliary atom is in the range of 396.3 eV to 396.5 eV, and the characteristic peak of the gap auxiliary atom is in the range of 396 eV to 401 eV.

[0093] The auxiliary atom 14a is present in the electron transport layer 104 in different forms to fill the defects in the electron transport layer 104 and increase the current density of the light emitting device 10.

[0094] For example, in the electron transport layer 104, the number of atoms of the gap auxiliary atom is greater than the number of atoms of the substitution auxiliary atom. That is, the auxiliary atom 14a is mostly present in the form of the gap auxiliary atom.

[0095] For example, the ratio of the number of atoms of the substitution auxiliary atom to the sum of the number of atoms of the substitution auxiliary atom and the number of atoms of the gap auxiliary atom is in the range of 20% to 35%. For example, the ratio of the number of atoms of the substitution auxiliary atom to the sum of the number of atoms of the substitution auxiliary atom and the number of atoms of the gap auxiliary atom is 20%, 22%, 23%, 25%, 27%, 29%, 30%, 31%, 33%, 34%, or 35%, and the like, but is not limited thereto.

[0096] In some embodiments, as shown in FIG. 6, the light-emitting device 10 further comprises a hole injection layer 107 and a hole transport layer 106, the hole transport layer 106 is located on the side of the light-emitting layer 103 away from the electron transport layer 104, and the hole injection layer 107 is located on the side of the hole transport layer 106 away from the light-emitting layer 103.

[0097] Exemplarily, the material of the hole injection layer 107 can include poly(3,4-ethylenedioxythiophene), polystyrene sulfonate, or other compounds suitable for hole injection layer, etc., which are not limited herein.

[0098] Exemplarily, the material of the hole transport layer 106 can include poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) or polyvinylcarbazole, etc., which are not limited herein.

[0099] The hole transport efficiency of the light-emitting device 10 can be improved by the arrangement of the hole injection layer 107 and the hole transport layer 106.

[0100] In some embodiments, as shown in FIG. 6, the light-emitting device 10 is a normal light-emitting device, and the anode 102, the hole injection layer 107, the hole transport layer 106, the light-emitting layer 103, the electron transport layer 104 and the cathode 105 of the light-emitting device 10 can be sequentially arranged in the direction away from the substrate 101.

[0101] In other embodiments, the light-emitting device 10 can be an inverted light-emitting device, and the anode 102, the hole injection layer 107, the hole transport layer 106, the light-emitting layer 103, the electron transport layer 104 and the cathode 105 of the light-emitting device 10 can be sequentially arranged in the direction close to the substrate 101.

[0102] In some embodiments, as shown in FIG. 6, the material of the electron transport layer 104 includes metal oxide nanoparticles or metal oxide film.

[0103] Exemplarily, the electron transport layer 104 is formed by radio frequency magnetron sputtering, and the material of the electron transport layer 104 is metal oxide film.

[0104] Exemplarily, the electron transport layer 104 is formed by spin coating, and the material of the electron transport layer 104 is metal oxide nanoparticles.

[0105] Embodiments of the present disclosure further provide a preparation method of a light-emitting device, as shown in FIG. 7, the preparation method of the light-emitting device comprises steps S1 and S2.

[0106] S1, as shown in FIG. 4, a substrate 101 is provided.

[0107] Exemplarily, the material of the substrate 101 can be a rigid material, such as glass; or the material of the substrate 101 can also be a flexible material, such as polyimide or polyethylene terephthalate.

[0108] S2, as shown in FIG. 4, forming the stacked anode 102, light-emitting layer 103, electron transport layer 104 and cathode 105 on one side of the substrate 101 to obtain the light-emitting device 10; wherein the material of the electron transport layer 104 comprises a metal oxide; the electron transport layer 104 further comprises hydrogen element 11, and the existing form of the hydrogen element 11 in the electron transport layer 104 comprises: substitutional hydrogen 11b bonded with atoms in the metal oxide and interstitial hydrogen 11a in a free state in the metal oxide; in the electron transport layer 104, the ratio of the number of atoms of the substitutional hydrogen 11b to the number of atoms of the hydrogen element 11 is greater than or equal to 10%.

[0109] In some examples, as shown in FIG. 8, forming the stacked anode 102, light-emitting layer 103, electron transport layer 104 and cathode 105 on one side of the substrate 101 to obtain the light-emitting device 10, specifically comprising steps: S21 and S22.

[0110] S21, as shown in FIG. 8, forming the stacked anode 102, light-emitting layer 103, initial electron transport layer 140 and cathode 105 on one side of the substrate 101 to obtain the initial light-emitting device 10a.

[0111] Exemplarily, the material of the anode 102 is indium tin oxide.

[0112] Exemplarily, before forming the light-emitting layer 103, further comprising: forming a hole injection layer 107 and a hole transport layer 106. For example, forming the hole injection layer 107 by spin-coating poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate on the side of the anode 102 away from the substrate 101, or forming the hole injection layer 107 by evaporating molybdenum oxide on the side of the anode 102 away from the substrate 101. Forming the hole transport layer 106 by spin-coating 1,2,4,5-tetrakis(trifluoromethyl)benzene or poly(9,9-n-dioctyl-2,7-fluorene-alt-9-iso-octyl-3,6-carbazole) on the side of the hole injection layer 107 away from the substrate 101, or forming the hole transport layer 106 by evaporating nickel oxide or tungsten oxide on the side of the hole injection layer 107 away from the substrate 101.

[0113] Exemplarily, forming the light-emitting layer 103 by a spin-coating process of quantum dot material.

[0114] Exemplarily, the nanoparticles are spin-coated on the side of the light-emitting layer 103 away from the substrate 101 to form an initial electron transport layer 140, or the initial electron transport layer 140 is formed on the side of the light-emitting layer 103 away from the substrate 101 by radio frequency magnetron sputtering. For example, the material of the initial electron transport layer 140 is zinc oxide, for example, the zinc oxide includes zinc elements 21 and oxygen elements 22 connected by chemical bonds.

[0115] Exemplarily, the cathode 105 is formed on the side of the initial electron transport layer 140 away from the substrate 101 by an evaporation process to form an initial light-emitting device 10a.

[0116] S22, as shown in FIG. 8, the initial light-emitting device 10a is processed under the condition of hydrogen and auxiliary gas to form an electron transport layer 104 from the initial electron transport layer 140, to obtain a light-emitting device 10; wherein the relative molecular mass or the relative atomic mass of the auxiliary gas is greater than or equal to 28.

[0117] Exemplarily, the auxiliary gas includes at least one of argon, nitrogen and xenon, and the auxiliary gas includes auxiliary atoms 14a.

[0118] Exemplarily, the processing mode of the initial light-emitting device 10a includes at least one of plasma bombardment, photoionization and field ionization. By processing the initial light-emitting device 10a under the condition of hydrogen and auxiliary gas by at least one of plasma bombardment, photoionization and field ionization, the auxiliary atoms 14a can break the chemical bond between the zinc elements 21 and the oxygen elements 22 to connect the hydrogen elements 11 with the zinc elements 21 and the oxygen elements 22 to form a structure of Zn-H-O or Zn-O-H, so as to increase the content of the substituted hydrogen 11b in the electron transport layer 104. For example, the substituted hydrogen 11b accounts for 25% to 35% of the hydrogen elements 11, which can make the hydrogen elements 11 more stably exist in the electron transport layer 104, so as to make the performance reliability of the light-emitting device 10 stronger.

[0119] Exemplarily, the initial electron transport layer 140 is formed by spin coating, and the initial light-emitting device 10a is processed under the condition that the volume ratio of the auxiliary gas to the hydrogen is 100:60 to 100:2 to form the electron transport layer 104. For example, the volume ratio of the auxiliary gas to the hydrogen is 100:60, 100:50, 100:45, 100:40, 100:30, 100:25, 100:20, 100:15, 100:10, 100:9, 100:8, 100:7, 100:6, 100:5, 100:3 or 100:2. By processing the initial light-emitting device 10a under the condition that the volume ratio of the auxiliary gas to the hydrogen is 100:60 to 100:2, the concentration range of the atomic number of the hydrogen elements 11 in the electron transport layer 104 can be 1014 cm -3 ~ 10 16 cm -3 The electron transport layer 104 is formed by a method of radio frequency magnetron sputtering.

[0120] For example, the ratio of the volume of the auxiliary gas to the volume of the hydrogen gas is 100:60, 100:50, 100:45, 100:40, 100:30, 100:25, 100:20, 100:15, 100:14, 100:13, 100:12, 100:11, or 100:10. By treating the initial light emitting device 10a under the condition that the ratio of the volume of the auxiliary gas to the volume of the hydrogen gas is 100:60 to 100:2, the concentration of the atomic number of the hydrogen element 11 in the electron transport layer 104 can be in the range of 1010atoms / cm3to 1012atoms / cm3. 14 cm -3 ~ 10 16 cm -3 The electron transport layer 104 is formed by a method of radio frequency magnetron sputtering.

[0121] The initial electron transport layer 140 formed by a method of radio frequency magnetron sputtering can generate more oxygen vacancies. The initial electron transport layer 140 can be treated with relatively more hydrogen gas so that more hydrogen element 11 exists in the electron transport layer 104 in the form of substitutional hydrogen 11b. Therefore, compared with treating the initial electron transport layer 140 formed by a method of spin coating, after the initial electron transport layer 140 is formed by a method of radio frequency magnetron sputtering, the minimum content of the volume of the hydrogen gas in the mixed gas formed by the auxiliary gas and the hydrogen gas relatively increases.

[0122] In some examples, as shown in FIG. 9, forming the initial electron transport layer 140 includes steps R1 and R2.

[0123] R1, forming the initial first sub-layer 1401 and the initial second sub-layer 1402 stacked, the material of the initial first sub-layer 1401 and the material of the initial second sub-layer 1402 being at least partially different.

[0124] For example, the initial first sub-layer 1401 and the initial second sub-layer 1402 stacked are formed by a method of spin coating.

[0125] For example, the material of the initial first sub-layer 1401 is zinc oxide nanoparticles, and the thickness of the initial first sub-layer 1401 is in the range of 15 nm to 20 nm.

[0126] Exemplarily, the material of the initial second sub-layer 1402 is magnesium oxide nanoparticles or tin oxide nanoparticles, and the thickness of the initial second sub-layer 1402 ranges from 10 nm to 20 nm.

[0127] R2, treating the initial light-emitting device 10a under the condition of hydrogen and auxiliary gas, the initial first sub-layer 1401 forms the first sub-layer 141, the initial second sub-layer 1402 forms the second sub-layer 142, an electron transport layer 104 including the first sub-layer 141 and the second sub-layer 142 is formed, and a light-emitting device 10 is obtained. The ratio of the volume of the auxiliary gas to the volume of the hydrogen ranges from 100:60 to 100:4.

[0128] Exemplarily, the ratio of the volume of the auxiliary gas to the volume of the hydrogen is 100:60, 100:50, 100:45, 100:40, 100:30, 100:25, 100:20, 100:15, 100:10, 100:9, 100:8, 100:7, 100:6, or 100:4, etc., which is not limited herein.

[0129] By treating the initial light-emitting device 10a with the mixed gas whose ratio of the volume of the auxiliary gas to the volume of the hydrogen ranges from 100:60 to 100:4, the electron transport layer 104 can be formed, in which the concentration of the number of atoms of hydrogen element 11 ranges from 10 18 cm -3 ~10 22 m -3 .

[0130] Through the above steps S1 and S2, the light-emitting device 10 is formed, in which the ratio of the number of atoms of substituted hydrogen 11b to the number of atoms of hydrogen element 11 in the electron transport layer 104 is greater than or equal to 10%, so that the hydrogen element 11 can exist more stably in the electron transport layer 104, and the performance reliability of the light-emitting device 10 is stronger.

[0131] In order to prove that the light-emitting device 10 provided by the embodiments of the present disclosure has stronger reliability, the following data is provided.

[0132] FIG. 10 is a luminance decay curve of the light-emitting device 10, wherein the structure of the light-emitting device 10 of Example 1 is shown in FIG. 3, and the light-emitting device 10 is not treated with hydrogen and auxiliary gas; the structure of the light-emitting device 10 of Example 2 is shown in FIG. 4, and the light-emitting device 10 is treated with hydrogen and auxiliary gas.

[0133] As can be seen from FIG. 10, the normalized luminance of the light emitting device 10 of Example 1 decays from 100 to below 95 in the range of normalized time 0-1. The normalized luminance of the light emitting device 10 of Example 2 decays from 100 to about 99.5 in the range of normalized time 0-1, and decays from 100 to about 95.5 in the range of normalized time 0-9.

[0134] Therefore, the performance reliability of the light emitting device 10 provided by the embodiments of the present disclosure is stronger.

[0135] The above merely provides a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can think of changes or replacements within the technical range disclosed by the present disclosure, which shall be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A light emitting device comprising: A substrate and, stacked on one side of the substrate, an anode, a light-emitting layer, an electron transport layer, and a cathode, a material of the electron transport layer comprising a metal oxide; The electron transport layer further comprises hydrogen elements, and a form of existence of the hydrogen elements in the electron transport layer comprises: substitution hydrogen bonded with atoms in the metal oxide and interstitial hydrogen in a free state in the metal oxide; and in the electron transport layer, a ratio of an atomic number of the substitution hydrogen to an atomic number of the hydrogen elements is greater than or equal to 10%.

2. The light-emitting device according to claim 1, wherein In the electron transport layer, the ratio of the atomic number of the substitution hydrogen to the atomic number of the hydrogen elements ranges from 25% to 35%.

3. The light emitting device according to claim 1 or 2, wherein The electron transport layer is a single layer, the concentration range of the atomic number of hydrogen element in the electron transport layer is 10 14 cm -3 ~ 10 16 cm -3 .

4. The light-emitting device according to claim 1 or 2, wherein The electron transport layer comprises: a first sub-layer and a second sub-layer stacked, materials of the first sub-layer and the second sub-layer being at least partially different; a concentration range of the atomic number of hydrogen elements in the electron transport layer is 10 18 cm -3 ~ 10 22 cm -3 .

5. The light-emitting device according to any one of claims 1 to 4, wherein The electron transport layer further comprises auxiliary atoms, and a relative atomic mass of the auxiliary atoms is greater than or equal to 14.

6. The light-emitting device according to claim 5, wherein The auxiliary atoms comprise at least one of argon atoms, nitrogen atoms, and xenon atoms.

7. The light emitting device according to claim 5 or 6, wherein The auxiliary atoms comprise at least one of argon atoms, nitrogen atoms, and xenon atoms.

8. The light-emitting device according to claim 7, wherein The auxiliary atoms comprise at least one of argon atoms, nitrogen atoms, and xenon atoms.

9. The light-emitting device according to claim 8, wherein In the electron transport layer, an atomic number of the interstitial auxiliary atoms is greater than an atomic number of the substitution auxiliary atoms.

10. The light-emitting device according to any one of claims 1 to 9, wherein A ratio of the atomic number of the substitution auxiliary atoms to a sum of the atomic number of the substitution auxiliary atoms and the atomic number of the interstitial auxiliary atoms ranges from 20% to 35%.

11. The light-emitting device according to any one of claims 1 to 10, wherein The light-emitting layer comprises quantum dot light-emitting materials. The electron transport layer comprises metal oxide nanoparticles or a metal oxide film.

12. A preparation method of a light-emitting device, comprising: providing a substrate; forming, on one side of the substrate, an anode, a light-emitting layer, an electron transport layer, and a cathode to obtain a light-emitting device; wherein a material of the electron transport layer comprises a metal oxide; the electron transport layer further comprises hydrogen elements, and a form of existence of the hydrogen elements in the electron transport layer comprises: substitution hydrogen bonded with atoms in the metal oxide and interstitial hydrogen in a free state in the metal oxide; and in the electron transport layer, a ratio of an atomic number of the substitution hydrogen to an atomic number of the hydrogen elements is greater than or equal to 10%.

13. The method of producing a light emitting device according to claim 12, wherein The forming, on one side of the substrate, an anode, a light-emitting layer, an electron transport layer, and a cathode to obtain a light-emitting device comprises: forming, on one side of the substrate, an anode, a light-emitting layer, an initial electron transport layer, and a cathode to obtain an initial light-emitting device; processing the initial light-emitting device under conditions of hydrogen and auxiliary gas to form the initial electron transport layer into an electron transport layer to obtain a light-emitting device; wherein a relative molecular mass or a relative atomic mass of the auxiliary gas is greater than or equal to 28.

14. The method of producing a light emitting device according to Claim 13, wherein The auxiliary gas comprises at least one of argon gas, nitrogen gas, and xenon gas.

15. The method of producing a light emitting device according to claim 13 or 14, wherein The forming the initial electron transport layer comprises: forming the initial electron transport layer in a manner of spin coating. The forming the initial electron transport layer comprises: forming the initial electron transport layer in a manner of radio frequency magnetron sputtering.

16. The method for producing a light emitting device according to claim 13 or 14, wherein The forming the initial electron transport layer comprises: forming the initial electron transport layer in a manner of radio frequency magnetron sputtering. The ratio of the volume of the auxiliary gas to the volume of the hydrogen gas ranges from 100:60 to 100:

10.

17. The method for producing a light emitting device according to claim 13 or 14, wherein Forming an initial electron transport layer, comprising: forming a stacked initial first sub-layer and an initial second sub-layer, the material of the initial first sub-layer and the material of the initial second sub-layer being at least partially different; processing the initial light-emitting device under the condition of hydrogen gas and auxiliary gas, the initial first sub-layer forming a first sub-layer, the initial second sub-layer forming a second sub-layer, forming an electron transport layer comprising the first sub-layer and the second sub-layer, to obtain a light-emitting device; The ratio of the volume of the auxiliary gas to the volume of the hydrogen gas ranges from 100:60 to 100:

4.

18. The method of producing a light-emitting device according to any one of claims 12 to 17, wherein The processing mode of the initial light-emitting device comprises at least one of plasma bombardment, photoionization and field ionization.

19. A display panel, comprising: The light-emitting device according to any one of claims 1-11; A pixel driving circuit for driving the light-emitting device to emit light.

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