Display panel, manufacturing method therefor, and display apparatus

Abstract

The present disclosure provides a display panel, a manufacturing method therefor, and a display apparatus. The display panel comprises an array substrate, a pixel define layer, and a plurality of light-emitting units. The pixel define layer is located on one side of the array substrate. The pixel define layer comprises a plurality of openings, and the light-emitting units are located in the openings in a one-to-one correspondence. Each light-emitting unit comprises a first electrode. The first electrode is located between the pixel define layer and the array substrate, and is electrically connected to the array substrate. The first electrode comprises a conductive matrix and a doping element doped in the conductive matrix. The doping element is further doped in side walls of the openings of the pixel define layer. A work function of the surface of the side of the first electrode facing the pixel define layer meets a condition, such that the degree of matching between the transport rates of holes and electrons in said light-emitting unit is greater than the degree of matching between the transport rates of holes and electrons in a light-emitting unit in which the material of a conductive matrix is directly used as a first electrode, thereby improving the light-emitting efficiency of the display panel.

Description

Display panel and manufacturing method thereof, and display device Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a display panel and a manufacturing method thereof, and a display device. Background Art

[0002] Quantum dot light emitting diodes (QLEDs) use quantum dot (QD) materials as the light-emitting layer. Compared with ordinary electroluminescent materials, quantum dot materials have the advantages of high luminescence purity, high emission efficiency, and emission wavelength that can be adjusted by the size of the quantum dot material. They have huge application potential in the field of display technology.

[0003] At present, during the light-emitting process of quantum dot light-emitting diodes, the imbalance in the transmission rates of holes and electrons easily causes non-radiative Auger recombination, resulting in low light-emitting efficiency of quantum dot light-emitting diodes.

[0004] Summary of the Invention

[0005] The present disclosure provides a display panel and a manufacturing method thereof, and a display device, so as to improve the luminous efficiency of the display panel.

[0006] According to a first aspect of the present disclosure, a display panel is provided, comprising an array substrate and a pixel defining layer located on one side of the array substrate, wherein the pixel defining layer comprises a plurality of openings, and further comprising:

[0007] A plurality of light-emitting units are located in the openings in a one-to-one correspondence; the light-emitting units include a first electrode, and the first electrode is electrically connected to the array substrate;

[0008] The first electrode includes a conductive matrix and an impurity element doped in the conductive matrix; the impurity element is also doped in the side wall of the opening of the pixel defining layer; the work function of the surface of the first electrode facing the pixel defining layer satisfies the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit, which is greater than the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the material of the conductive matrix is ​​directly used as the first electrode.

[0009] In the display panel provided by the present disclosure, the multiple light-emitting units include a first light-emitting unit and a second light-emitting unit; the work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is greater than the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer.

[0010] In the display panel provided by the present disclosure, the work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is greater than the work function of the material of the conductive substrate; the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer is smaller than the work function of the material of the conductive substrate.

[0011] In the display panel provided by the present disclosure, the light-emitting unit further includes a light-emitting functional layer and a second electrode stacked in sequence on a side of the first electrode facing away from the array substrate;

[0012] The light-emitting functional layer includes a quantum dot light-emitting layer;

[0013] The first light-emitting unit includes a red light-emitting unit and a green light-emitting unit; the quantum dot light-emitting layer of the red light-emitting unit includes a red quantum dot light-emitting material; the quantum dot light-emitting layer of the green light-emitting unit includes a green quantum dot light-emitting material;

[0014] The second light-emitting unit is a blue light-emitting unit; the quantum dot light-emitting layer of the blue light-emitting unit includes a blue quantum dot light-emitting material.

[0015] In the display panel provided by the present disclosure, the content of defective oxygen on the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is less than the content of defective oxygen on the surface of the first electrode of the second light-emitting unit facing the pixel defining layer.

[0016] In the display panel provided by the present disclosure, the doping elements in the first electrode are concentrated on a side of the conductive substrate close to the pixel defining layer.

[0017] In the display panel provided by the present disclosure, the thickness of the first electrode is 60 nm to 100 nm; the thickness of the doping elements concentrated in the conductive matrix is ​​less than or equal to 20 nm.

[0018] In the display panel provided by the present disclosure, the material of the pixel defining layer is an inorganic material containing silicon.

[0019] In the display panel provided by the present disclosure, the doping element includes at least fluorine.

[0020] In the display panel provided by the present disclosure, the material of the pixel defining layer is silicon oxide.

[0021] In the display panel provided by the present disclosure, the material of the conductive substrate includes indium tin oxide.

[0022] In the display panel provided by the present disclosure, the sheet resistance of the first electrode is greater than the sheet resistance of the material of the conductive substrate.

[0023] In the display panel provided by the present disclosure, the first electrode is the anode of the light-emitting unit.

[0024] In the display panel provided by the present disclosure, the first electrode is the cathode of the light-emitting unit.

[0025] According to a second aspect of the present disclosure, a display device is provided, comprising any one of the display panels described above.

[0026] A third aspect of the present disclosure provides a method for manufacturing a display panel, comprising:

[0027] A plurality of conductive substrates are formed on one side of the array substrate through a patterning process; the conductive substrates are electrically connected to the array substrate;

[0028] forming a pixel defining layer on a side of the conductive base facing away from the array substrate;

[0029] Etching the pixel defining layer with an etching gas to form openings corresponding to the conductive substrate and exposing the conductive substrate;

[0030] The conductive substrate exposed by the opening is subjected to surface treatment using an etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer, thereby forming a plurality of first electrodes; the work function of the surface of the first electrode facing the pixel defining layer satisfies the requirement that the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit is greater than the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the material of the conductive substrate is directly used as the first electrode;

[0031] A light-emitting functional layer and a second electrode are sequentially formed on a side of the first electrode facing away from the base substrate to form a light-emitting unit.

[0032] In the method provided by the present disclosure, the pixel defining layer is etched by etching gas to form an opening corresponding to the conductive substrate and exposing the conductive substrate;

[0033] The surface of the conductive substrate exposed by the opening is treated by etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer to form a plurality of first electrodes, specifically comprising:

[0034] forming a first patterned photoresist layer on a side of the pixel defining layer facing away from the conductive substrate; the first patterned photoresist layer includes first etching openings corresponding one-to-one to the first portion of the conductive substrate;

[0035] Etching the pixel defining layer exposed by the first etching opening using a first etching gas to form a first partial opening;

[0036] Performing surface treatment on the conductive substrate exposed by the first opening by using a first etching gas, so that the conductive substrate has a first work function, thereby forming a first portion of the first electrode;

[0037] The first patterned photoresist layer is removed, and a second patterned photoresist layer is formed on a side of the pixel defining layer facing away from the conductive substrate; the second patterned photoresist layer includes second etching openings corresponding one-to-one to the second portion of the conductive substrate, and the second patterned photoresist layer completely covers the first portion of the openings;

[0038] Etching the pixel defining layer exposed by the second etching opening using a second etching gas to form a second partial opening;

[0039] The conductive substrate exposed by the second opening is surface-treated by a second etching gas to give the conductive substrate a second work function, thereby forming a second portion of the first electrode; the second work function is different from the first work function.

[0040] In the method provided by the present disclosure, the first etching gas is an oxidizing gas mixture; the second etching gas is a reducing gas mixture.

[0041] In the method provided by the present disclosure, the components of the first etching gas include CF4 and O2; the components of the second etching gas include CHF3, Ar and H2.

[0042] The beneficial effects of the present disclosure are as follows:

[0043] The present disclosure provides a display panel, a manufacturing method thereof, and a display device, wherein the display panel comprises: an array substrate, a pixel defining layer, and a plurality of light-emitting units; the pixel defining layer is located on one side of the array substrate; the pixel defining layer comprises a plurality of openings; the light-emitting units are located in the openings one by one; the light-emitting units comprise a first electrode, which is electrically connected to the array substrate; the first electrode comprises a conductive matrix and an impurity element doped in the conductive matrix; the impurity element is also doped in the sidewalls of the openings of the pixel defining layer; the work function of the surface of the first electrode facing the pixel defining layer satisfies the matching degree between the transmission rate of holes and the transmission rate of electrons in the light-emitting units, which is greater than the matching degree between the transmission rate of holes and the transmission rate of electrons in the light-emitting units in which the material of the conductive matrix is ​​directly used as the first electrode, thereby improving the luminous efficiency of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments of the present disclosure. Obviously, the drawings introduced below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] FIG1 is a schematic diagram of a cross-sectional structure of a display panel according to an embodiment of the present disclosure;

[0046] FIG2 is a partially enlarged view of the cross-sectional structure of a display panel provided in an embodiment of the present disclosure;

[0047] FIG3 is a second schematic diagram of a cross-sectional structure of a display panel provided in an embodiment of the present disclosure;

[0048] FIG4 is a graph showing oxygen element peaks on the surface of the first electrode after being treated with different etching gases according to an embodiment of the present disclosure;

[0049] FIG5 is a distribution curve diagram of doping elements in the first electrode provided by an embodiment of the present disclosure;

[0050] FIG6 is a flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure;

[0051] FIG7 is a second flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure;

[0052] FIG8a is a schematic diagram of a manufacturing process of a display panel according to an embodiment of the present disclosure;

[0053] FIG8 b is a second schematic diagram of the manufacturing process of the display panel provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0054] In order to make the above-mentioned purposes, features and advantages of the present disclosure more obvious and easy to understand, the present disclosure will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present disclosure more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in the present disclosure are all explained using the accompanying drawings as examples, but changes can be made as needed, and all changes are included in the scope of protection of the present disclosure. The drawings of the present disclosure are only used to illustrate relative position relationships and do not represent true proportions.

[0055] Quantum dot light emitting diodes (QLEDs) use quantum dot (QD) materials as the light-emitting layer. Compared with ordinary electroluminescent materials, quantum dot materials have the advantages of high luminescence purity, high emission efficiency, emission wavelength that can be adjusted by the size of the quantum dot material, and high stability. They have huge application potential in the field of display technology.

[0056] Quantum dot light-emitting diodes typically include an anode, a cathode, and a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electron injection layer, stacked sequentially between the anode and cathode. Holes injected from the anode through the hole injection layer are then transported through the hole transport layer to the quantum dot light-emitting layer. Electrons injected from the cathode through the electron injection layer are then transported through the electron transport layer to the quantum dot light-emitting layer, where they recombine with holes and emit light. Currently, the light-emitting process of quantum dot light-emitting diodes suffers from an imbalance in the transport of holes and electrons, which can easily lead to non-radiative Auger recombination, resulting in reduced luminous efficiency.

[0057] In view of this, embodiments of the present disclosure provide a display panel to solve the above-mentioned problem.

[0058] FIG1 is one of schematic diagrams of a cross-sectional structure of a display panel provided in an embodiment of the present disclosure; FIG2 is a partially enlarged view of a cross-sectional structure of a display panel provided in an embodiment of the present disclosure.

[0059] In the embodiment of the present disclosure, as shown in FIG1 , the display panel includes: an array substrate 100 , a pixel defining layer 200 and a light emitting unit 300 .

[0060] The array substrate 100 is located at the bottom of the display panel, and the light-emitting unit 300 is located on the array substrate 100 and is electrically connected to the array substrate 100. The array substrate 100 is used to carry the light-emitting unit 300 and to drive the light-emitting unit 300 to emit light to display images. The shape of the array substrate 100 is adapted to the shape of the display panel, for example, it can be square, rectangular, etc. When used in a special-shaped display panel, the array substrate 100 can also be a special-shaped shape such as a circle, which is not limited here. The array substrate 100 can be a thin film transistor (TFT) substrate. The thin film transistor substrate includes a pixel circuit composed of multiple thin film transistors and capacitors. A pixel circuit is electrically connected to a light-emitting unit 300 and is used to drive the light-emitting unit 300 electrically connected to it to emit light, realizing active matrix (AM) driven display. The thin film transistor substrate may include a substrate and a drive circuit layer located on the substrate, and the pixel circuit is located in the drive circuit layer. The substrate can be made of a rigid material, such as glass, to realize a rigid display panel; the substrate can also be made of a flexible material, such as polyimide (PI), to realize a flexible display panel, without limitation herein. In some embodiments, the array substrate 100 can also be other types of drive substrates, such as a complementary metal-oxide-semiconductor (CMOS) substrate or a printed circuit board (PCB), without limitation herein.

[0061] The pixel defining layer 200 is located on one side of the array substrate 100. The pixel defining layer 200 includes a plurality of openings K extending through the pixel defining layer 200 along its thickness. The thickness of the pixel defining layer 200 specifically refers to the direction in which the pixel defining layer 200 is stacked on the array substrate 100. The openings K in the pixel defining layer 200 are used to define the positions of the pixel units, and therefore, the positions of the light-emitting units 300. The light-emitting units 300 are disposed one-to-one within the openings K in the pixel defining layer 200.

[0062] The light emitting unit 300 is used to emit light under the drive of the array substrate 100 to display images. The light emitting unit 300 includes a first electrode 301. The first electrode 301 is located between the pixel defining layer 200 and the array substrate 100 and is electrically connected to the array substrate 100.

[0063] FIG2 is a partial enlarged view of area A in FIG1 . As shown in FIG2 , the first electrode 301 includes a conductive substrate 3011 and a doping element d doped in the conductive substrate 3011. The doping element d is also doped in the sidewalls 201 of the openings K in the pixel defining layer 200. In a specific implementation, before forming the pixel defining layer 200, the conductive substrate 3011 can be first formed on the array substrate 100 through a patterning process. The pixel defining layer 200 is then formed on a side of the conductive substrate 3011 facing away from the array substrate 100. The pixel defining layer 200 is then etched through a dry etching process to form a plurality of openings K. The openings K at least partially expose the conductive substrate 3011 to facilitate the subsequent fabrication of the light-emitting unit 300. During the manufacturing process of the display panel provided by the embodiments of the present disclosure, the pixel defining layer 200 is etched using a dry etching process to form an opening K penetrating the pixel defining layer 200. The surface of the conductive substrate 3011 is then treated with the etching gas used in the dry etching process to modify the work function of the conductive substrate 3011 surface, thereby forming the first electrode 301. The work function of the surface of the first electrode 301 facing the pixel defining layer 200 satisfies the matching degree between the hole and electron transmission rates in the light-emitting unit 300, exceeding the matching degree between the hole and electron transmission rates in a light-emitting unit using the conductive substrate material directly as the first electrode, thereby improving the luminous efficiency. The work function refers to the minimum energy required to move an electron from the interior of a solid to the surface of the solid and is used to characterize the degree to which the solid binds electrons. For the first electrode, a higher work function indicates a higher electron binding and a lower electron injection resistance. Conversely, holes are more easily injected into the light-emitting unit. A lower work function indicates an easier electron injection and a lesser hole injection resistance. The material of the conductive substrate may be a commonly used electrode material, specifically a metal, a metal oxide or a conductive polymer, etc., which is not limited here.

[0064] For example, in traditional red quantum dot light-emitting diodes and green quantum dot light-emitting diodes made of cadmium-based quantum dot materials, electrons are majority carriers. During the light-emitting process, the transmission rate of electrons is much greater than the transmission rate of holes. The transmission rate difference between electrons and holes is large, and the matching degree is low, which causes a large amount of Auger recombination and leads to the problem of low luminous efficiency. The first electrode can be the anode of the quantum dot light-emitting diode. The material used for the anode of the traditional cadmium-based red quantum dot light-emitting diode and the cadmium-based green quantum dot light-emitting diode is used as the material of the conductive substrate 3011 in the embodiment of the present disclosure. Based on the structure of the traditional cadmium-based red quantum dot light-emitting diode and the cadmium-based green quantum dot light-emitting diode, the anode of the quantum dot light-emitting diode can be surface-treated with an etching gas during the etching of the pixel defining layer 200 to improve the work function of the anode, reduce the barrier for holes to be injected from the anode into the hole injection layer, thereby improving the hole injection ability, reducing the difference in transmission rate between holes and electrons, and improving the matching degree of transmission rate between holes and electrons, thereby greatly improving the luminous efficiency.

[0065] The work function of the surface of the first electrode facing the pixel defining layer in the embodiments of the present disclosure satisfies the requirement that the degree of matching between the hole transmission rate and the electron transmission rate in the light-emitting unit is greater than the degree of matching between the hole transmission rate and the electron transmission rate in a light-emitting unit in which the conductive substrate material is directly used as the first electrode. Specifically, when the light-emitting unit in the display panel provided by the embodiments of the present disclosure emits light, the difference between the hole transmission rate and the electron transmission rate is less than the difference between the hole transmission rate and the electron transmission rate in a light-emitting unit in which the conductive substrate material is directly used as the first electrode. That is, in the display panel provided by the embodiments of the present disclosure, the difference between the hole transmission rate and the electron transmission rate in the light-emitting unit is small, and the degree of matching is large, which is conducive to reducing Auger recombination and improving luminous efficiency. It should be noted that in the display panel provided by the embodiments of the present disclosure, the hole transmission rate and the electron transmission rate in the light-emitting unit can be exactly the same, or there can be a certain difference, but the difference is smaller than the difference between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the conductive substrate material is directly used as the first electrode. When making a specific comparison, the two light-emitting units to be compared use the same structure and materials except for the first electrode. Among them, the light-emitting unit in the display panel provided by the embodiment of the present disclosure performs the above-mentioned surface treatment on the surface of the conductive substrate by etching gas to form the first electrode, so that the work function of the surface of the first electrode facing the pixel defining layer meets the above-mentioned conditions, while the light-emitting unit for comparison directly uses the conductive substrate as the first electrode. The first electrode of the light-emitting unit for comparison does not undergo the same surface treatment process as the light-emitting unit in the display panel provided by the embodiment of the present disclosure, and therefore cannot achieve the same luminous efficiency as the light-emitting unit in the display panel provided by the embodiment of the present disclosure.

[0066] A doping element specifically refers to an element that is not present in the material used to form the conductive substrate 3011 or the material used to form the pixel defining layer 200 before the etching process, or, after the etching process, the content of the element in the surface layer of the conductive substrate 3011 facing the pixel defining layer and in the sidewalls of the opening of the pixel defining layer 200 is greater than before the etching process. The doping element is ionized by the etching gas during the etching of the pixel defining layer and the surface treatment of the conductive substrate, and is doped into the conductive substrate and the pixel defining layer through diffusion or reaction with the surface of the conductive substrate and the sidewalls of the pixel defining layer.

[0067] For example, the material of the pixel defining layer 200 can be an inorganic material. When the pixel defining layer 200 is made of an inorganic material, when the pixel defining layer 200 is etched by a dry etching process to form an opening K, a photoresist can be used as a mask to protect the non-etched area of ​​the pixel defining layer 200. Since the photoresist is usually an organic material, when dry etching is performed, the etching gas selectively etches the inorganic material of the pixel defining layer 200 in the area to be etched exposed by the photoresist, and hardly etches the organic material of the photoresist or etches it at a very low rate, thereby avoiding the expansion of the photoresist opening due to etching during the dry etching process, reducing etching deviation, and improving etching accuracy. The material of the pixel defining layer 200 can also be an organic material, which is not limited here.

[0068] In some embodiments, the inorganic material used in the pixel defining layer 200 may be a silicon-containing compound, such as silicon oxide (SiO X ), silicon nitride (SiN X ) or silicon oxynitride (SiON), etc., are not limited here. When etching silicon-containing compounds, the etching gas generally includes a fluorine-containing gas, such as CHF3, CF4, etc., which reacts with the silicon-containing compound to generate a volatile gas, thereby improving the etching efficiency. During the etching process and during the surface treatment of the conductive substrate, the fluorine element penetrates into the sidewalls of the pixel defining layer 200 and the surface of the conductive substrate, forming a doping element.

[0069] Since the surface treatment of the conductive substrate of the first electrode by the etching gas occurs on the side of the conductive substrate facing the pixel defining layer, the doping elements in the first electrode are concentrated on the side of the conductive substrate close to the pixel defining layer. In the embodiment of the present disclosure, the doping elements in the first electrode are concentrated on the side of the conductive substrate close to the pixel defining layer, specifically referring to that the majority of the doping elements in the first electrode are present within a smaller thickness on the side of the conductive substrate close to the pixel defining layer, for example, more than half of the doping elements are present within less than half of the thickness of the first electrode on the side of the conductive substrate close to the pixel defining layer. Specifically, the thickness of the first electrode is generally set to 60nm to 150nm, for example, it can be 70nm, and within the thickness range of less than or equal to 20nm on the side of the conductive substrate close to the pixel defining layer, the content of the doping elements can generally account for more than 99% of the content of the doping elements along the thickness direction of the first electrode.

[0070] FIG3 is a second schematic diagram of the cross-sectional structure of the display panel provided in an embodiment of the present disclosure.

[0071] In some embodiments, the plurality of light-emitting units may include a first light-emitting unit 310 and a second light-emitting unit 320. The first light-emitting unit 310 and the second light-emitting unit may be light-emitting units for emitting light of different colors. For light-emitting units that emit light of different colors, such as quantum dot light-emitting diodes of different colors, due to the different quantum dot luminescent materials, the differences in hole transfer rates and electron transfer rates in quantum dot light-emitting diodes of different colors are also different. For example, for red quantum dot light-emitting diodes and green quantum dot light-emitting diodes made of traditional cadmium-based quantum dot materials, such as CdSe, CdS and other group II-VI quantum dot materials, electrons are majority carriers. During the light-emitting process, the electron transfer rate is much greater than the hole transfer rate. Therefore, the first electrode is required to have a higher work function to improve the hole injection efficiency or reduce the electron injection efficiency, thereby reducing the difference between the hole transfer rate and the electron transfer rate. For blue quantum dot light-emitting diodes made of traditional cadmium quantum dot materials, such as blue quantum dot light-emitting diodes made of CdZnSeS quantum dot materials, the electron injection efficiency is slow, so the first electrode needs to have a lower work function to improve the electron injection efficiency, thereby reducing the difference between the electron transmission rate and the hole transmission rate. Thus, for light-emitting units emitting different colors, the first electrode can have different work functions. In the embodiment of the present disclosure, the work function of the surface of the first electrode 301 of the first light-emitting unit 310 facing the pixel defining layer 200 is greater than the work function of the surface of the first electrode 301 of the second light-emitting unit 302 facing the pixel defining layer 200.

[0072] In the disclosed embodiments, the conductive substrates of the first electrodes 301 of all light-emitting units in the display panel can be made of the same material, such as indium tin oxide (ITO), so that all conductive substrates can be formed simultaneously through a single patterning process, simplifying the process steps. This is not limited here. In some embodiments, for conductive substrates made of the same material, different etching gases can be used for etching the pixel defining layer 200 and surface treating the first electrodes 301 of the first light-emitting unit 310 and the second light-emitting unit 320, respectively. A first etching gas can be used for the first light-emitting unit 310 to increase the work function of the conductive substrate surface, such that the work function of the surface of the first electrode 301 of the first light-emitting unit 310 facing the pixel defining layer 200 is greater than the work function of the conductive substrate material. A second etching gas can be used for the second light-emitting unit 320 to decrease the work function of the conductive substrate surface, such that the work function of the surface of the first electrode 301 of the second light-emitting unit 320 facing the pixel defining layer 200 is greater than the work function of the conductive substrate material.

[0073] FIG4 is a diagram showing the peak position of oxygen elements on the surface of the first electrode after being treated with different etching gases according to an embodiment of the present disclosure; FIG5 is a diagram showing the distribution curve of doping elements in the first electrode according to an embodiment of the present disclosure.

[0074] In the embodiment of the present disclosure, the conductive substrate 3011 of the first electrode 301 is patterned indium tin oxide (ITO), and the material of the pixel defining layer 200 is silicon oxide (SiO X ), the changes in work function and surface element content after surface treatment of the conductive substrate 3011 of the first electrode 301 using different etching gases were studied. Indium tin oxide is typically used in an etching process to form a patterned conductive substrate 3011. Impurities may infiltrate the conductive substrate during the patterning process, and the conductive substrate is also susceptible to impurities when exposed to air. Therefore, in specific implementations, the conductive substrate material may include indium tin oxide and a small amount of impurity elements.

[0075] The work function and sheet resistance of the surface of the first electrode 301 after the conductive substrate 3011 of the first electrode 301 is treated with different etching gases are shown in Table 1 below:

[0076] Table 1 Work function and square resistance after treatment with different etching gases

[0077] The surface element contents of the first electrode 301 subjected to surface treatment using different processes are shown in Table 2 below:

[0078] Table 2 Element content after treatment with different etching gases

[0079] The test process using process 1 includes the following steps:

[0080] 1. Depositing an indium tin oxide layer on the array substrate and forming multiple conductive bases through a patterning process;

[0081] 2. Directly test the work function, square resistance and element content of the conductive substrate.

[0082] The testing process using Process 2 includes the following steps:

[0083] 1. Depositing an indium tin oxide layer on the array substrate and forming multiple conductive bases through a patterning process;

[0084] 2. Depositing silicon oxide material on the side of the conductive base away from the array substrate to form a pixel defining layer;

[0085] 3. Coating a first photoresist layer on the side of the pixel defining layer facing away from the array substrate, and performing exposure and development processes on the photoresist layer to expose the area of ​​the pixel defining layer to be etched;

[0086] 4. Etching the pixel defining layer exposed by the first photoresist layer using a first etching gas to form an opening penetrating the pixel defining layer, and performing a surface treatment on the conductive substrate exposed by the opening using the first etching gas; wherein the first etching gas comprises CF4 and O2, and the flow rates of CF4 and O2 are 400 sccm and 80 sccm, respectively, and the total duration of the etching and surface treatment is 61 seconds;

[0087] 5. Test the work function, sheet resistance, and element content of the first electrode surface obtained after surface treatment.

[0088] The testing process using Process 3 includes the following steps:

[0089] 1. Depositing an indium tin oxide layer on the array substrate and forming multiple conductive bases through a patterning process;

[0090] 2. Depositing silicon oxide material on the side of the conductive base away from the array substrate to form a pixel defining layer;

[0091] 3. Coating a second photoresist layer on the side of the pixel defining layer facing away from the array substrate, and performing exposure and development processes on the photoresist layer to expose the area of ​​the pixel defining layer to be etched;

[0092] 4. Etching the pixel defining layer exposed by the second photoresist layer using a second etching gas to form an opening penetrating the pixel defining layer, and performing surface treatment on the conductive substrate exposed by the opening using the second etching gas; wherein the second etching gas comprises CHF3, Ar, and H2, and the flow rates of CHF3, Ar, and H2 are 200 sccm, 200 sccm, and 25 sccm, respectively. The total duration of etching and surface treatment is 104 s;

[0093] 5. Test the work function, sheet resistance, and element content of the first electrode surface obtained after surface treatment.

[0094] The testing processes using process 1, process 2, and process 3 are respectively performed on three array substrates.

[0095] According to the work function and square resistance of the surface of the first electrode after surface treatment with different etching gases in Table 1, after surface treatment with the first etching gas (process 2), the work function of the surface of the first electrode is improved compared to the work function of the conductive substrate (process 1). For example, the first electrode after surface treatment with the first etching gas is used to form a red quantum dot light-emitting diode and a green quantum dot light-emitting diode of a traditional cadmium quantum dot light-emitting material, which is beneficial to improving the hole injection efficiency or reducing the electron injection efficiency, thereby reducing the difference between the hole transport efficiency and the electron transport efficiency and improving the luminous efficiency. After surface treatment with the second etching gas (process 3), the work function of the surface of the first electrode is reduced compared to the work function of the conductive substrate (process 1). For example, the first electrode after surface treatment with the second etching gas is used to form a blue quantum dot light-emitting diode of a traditional cadmium quantum dot light-emitting material, which is beneficial to reducing the hole injection efficiency or improving the electron injection efficiency, thereby reducing the difference between the hole transport efficiency and the electron transport efficiency and improving the luminous efficiency. However, the sheet resistance of the first electrode surface-treated by the first etching gas (process 2) and the second etching gas (process 3) is slightly increased compared with the sheet resistance of the conductive substrate without surface treatment.

[0096] The element content on the surface of the first electrode was tested using an X-ray photoelectron spectroscopy (XPS) instrument. X-ray photoelectron spectroscopy is a surface analysis technique that can generally detect the element content within 10 nm of the surface of the object to be tested. As shown in Table 2, the surfaces of the first electrodes tested using Process 1, Process 2, and Process 3 all contain carbon (C1s), most of which are impurities adsorbed by the sample when exposed to the atmosphere. The C-C bond chemical properties are relatively stable, with a corresponding binding energy of 284.8 eV. It is a stable internal standard that can be used for XPS data analysis and correction. As shown in Table 2, after surface treatment using Process 2 and Process 3, the fluorine (F1s) content on the surface of the first electrode increased significantly, while the indium (In3d) and tin (Sn3d) contents decreased. It is speculated that fluorine was doped on the surface of the first electrode during the surface treatment process, thereby reducing the content of indium and tin, causing the square resistance of the first electrode to increase after surface treatment using Process 2 and Process 3. As shown in Figure 4, peak fitting is performed on the oxygen element (O1S) on the surface of the first electrode after treatment using Process 1, Process 2, and Process 3, where the abscissa represents the binding energy and the ordinate represents the photoelectron signal intensity. Combined with Figure 4 and Table 2, the contents of lattice oxygen (O1s O1), defect oxygen (O1s O2), and adsorbed oxygen (O1s O3) change after surface treatment using Process 2 and Process 3 compared to Process 1, thereby affecting the work function of the first electrode surface. Specifically, after surface treatment using Process 2 and Process 3, the contents of lattice oxygen (O1s O1) and adsorbed oxygen (O1s O3) on the surface of the first electrode decrease compared to the contents of lattice oxygen (O1s O1) and adsorbed oxygen (O1s O3) on the surface of the conductive substrate that has not been surface treated, while the content of defect oxygen (O1s O2) increases compared to the content of defect oxygen (O1s O2) on the surface of the conductive substrate that has not been surface treated. Among them, the change in the content of defective oxygen (O1s O2) plays a key role in affecting the work function during the surface treatment of the first electrode. As shown in Table 2, the content of defective oxygen (O1s O2) on the surface of the first electrode treated with process 2 is much smaller than the content of defective oxygen (O1s O2) on the surface of the first electrode treated with process 3, thereby making the work function of the surface of the first electrode treated with the first etching gas greater than the work function of the surface of the first electrode treated with the second etching gas.

[0097] Since XPS technology can only detect the element content within 10nm of the surface of the object to be tested, the present disclosure also uses Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) to further analyze the longitudinal distribution of the doping element (fluorine element) in the first electrode after surface treatment along the thickness direction of the first electrode. Taking process 1 and process 2 as examples, the thickness of the first electrode is 70nm. As shown in Figure 5, where the horizontal axis represents the film depth and the vertical axis represents the signal intensity, process 1 contains a small amount of fluorine element, which is presumably an impurity element that is inherent in the material used to form the conductive substrate and introduced during the production of the conductive substrate. After surface treatment of the first electrode using process 2, the fluorine content increases significantly. Furthermore, the fluorine signal intensity increases and then decreases from the side of the first electrode closest to the pixel defining layer to the side farther from the pixel defining layer. The fluorine signal intensity, which indicates the amount of fluorine, reaches a maximum at a film depth of approximately 1 nm and then slowly decreases. At a film depth of approximately 10 nm, the fluorine signal intensity changes gradually. This indicates that after the film depth exceeds 10 nm, the content of the doping element decreases, and the doping element is primarily concentrated within a thickness of less than 10 nm on the surface of the first electrode. As shown in Figure 5, the fluorine signal intensity shows a sudden increase at a film depth of approximately 100 nm. Since the first electrode is only 70 nm thick, the sudden increase in fluorine signal intensity at a film depth of approximately 100 nm indicates that other film layers beneath the first electrode have been detected.

[0098] In some embodiments, different etching gases may be used to perform surface treatment on the first electrode 301 of the first light-emitting unit 310 and the first electrode 301 of the second light-emitting unit 320, respectively. Both the surface treatment of the first electrode 301 of the first light-emitting unit 310 and the surface treatment of the first electrode 301 of the second light-emitting unit 320 are used to increase or decrease the work function of the surfaces of the first electrode 301 of the first light-emitting unit 310 and the first electrode 301 of the second light-emitting unit 320, respectively. The magnitude of the increase or decrease in the work function differs between the first light-emitting unit 310 and the second light-emitting unit 320. This is not limited to the above as long as the difference between the electron transmission rate and the hole transmission rate in each of the first light-emitting unit 310 and the second light-emitting unit 320 is smaller than that in a light-emitting unit that directly uses an unsurface-treated conductive substrate as the first electrode.

[0099] In some embodiments, the light-emitting unit may be a quantum dot light-emitting diode. As shown in Figure 3, the light-emitting unit further includes a light-emitting functional layer and a second electrode 302 stacked sequentially on a side of a first electrode 301 facing away from the array substrate 100. The light-emitting functional layer is located between the first electrode 301 and the second electrode 302. The light-emitting functional layer includes a quantum dot light-emitting layer 303, where holes injected from the anode and electrons injected from the cathode recombine, thereby emitting light.

[0100] In some embodiments, the first electrode can be the anode of the light-emitting unit. According to actual needs, the first electrode can have a higher work function to improve the injection efficiency of holes, or the first electrode can have a lower work function to reduce the injection efficiency of holes. For example, as shown in Figure 3, from the direction of the first electrode 301 to the second electrode 302, the light-emitting unit may include a first electrode 301, a hole injection layer, a hole transport layer, a quantum dot light-emitting layer 303, an electron transport layer, an electron injection layer and a second electrode 302 stacked in sequence. In specific implementations, the light-emitting unit may also include more functional film layers, such as a hole blocking layer and an electron blocking layer, or include fewer functional film layers, which is not limited here.

[0101] In some embodiments, the first electrode can be the cathode of the light-emitting unit. According to actual needs, the first electrode can have a higher work function to reduce the injection efficiency of electrons, or the first electrode can have a lower work function to improve the injection efficiency of electrons. For example, as shown in Figure 3, from the direction of the first electrode 301 to the second electrode 302, the light-emitting unit may include a first electrode 301, an electron injection layer, an electron transport layer, a quantum dot light-emitting layer 303, a hole transport layer, a hole injection layer and a second electrode 302 stacked in sequence. In specific implementations, the light-emitting unit may also include more functional film layers, such as a hole blocking layer and an electron blocking layer, or include fewer functional film layers, which is not limited here.

[0102] In some embodiments, as shown in FIG3 , the first light-emitting unit 310 includes a red light-emitting unit 311 and a green light-emitting unit 312. The quantum dot light-emitting layer 303 of the red light-emitting unit 311 includes a red quantum dot material, such as CdSe, and the quantum dot light-emitting layer 303 of the green light-emitting unit 312 includes a green quantum dot light-emitting material, such as CdSe. When the quantum dot light-emitting layer 303 of the red light-emitting unit 311 and the quantum dot light-emitting layer 303 of the green light-emitting unit 312 use the same quantum dot light-emitting material, the quantum dots in the quantum dot light-emitting layer 303 of the red light-emitting unit 311 and the quantum dots in the quantum dot light-emitting layer 303 of the green light-emitting unit 312 have different sizes. The second light-emitting unit 320 is a blue light-emitting unit. The quantum dot light-emitting layer 303 of the blue light-emitting unit includes a blue quantum dot light-emitting material, such as CdZnSeS, but the material is not limited here.

[0103] In some embodiments, since both the first electrode of the red light-emitting unit 311 and the first electrode of the green light-emitting unit 312 require a relatively high work function, in a specific implementation, the first electrode of the red light-emitting unit 311 and the first electrode of the green light-emitting unit 312 can be simultaneously surface-treated using the same etching gas, thereby having the same or similar work function. For example, when etching the pixel defining layer to form an opening exposing the conductive substrate, the opening corresponding to the red light-emitting unit 311 and the opening corresponding to the green light-emitting unit 312 can be etched simultaneously using the first etching gas, thereby reducing the process steps of separately etching the opening corresponding to the red light-emitting unit 311 and the opening corresponding to the green light-emitting unit 312. In some embodiments, different etching gases can also be used to etch the opening corresponding to the red light-emitting unit 311 and the opening corresponding to the green light-emitting unit 312, respectively, so that the work function of the first electrode of the red light-emitting unit 311 and the work function of the first electrode of the green light-emitting unit 312 are more closely matched to their respective systems, which is not limited here.

[0104] In some embodiments, the display panel may be a bottom-emitting display panel. In a bottom-emitting display panel, light is emitted from the side where the array substrate is located to display an image. The first electrode is a transparent electrode to improve transmittance. For example, the conductive substrate of the first electrode may be made of a transparent material such as indium tin oxide.

[0105] In some embodiments, the display panel may be a top-emitting display panel. In a top-emitting display panel, light is emitted from the opposite side of the array substrate to display an image, and the first electrode may be a non-transparent electrode. In some embodiments, the first electrode may also be a transparent electrode. For example, the conductive substrate of the first electrode may be made of a transparent material such as indium tin oxide. In this case, at least one reflective electrode may be formed between the first electrode and the array substrate to reflect light propagating toward the side of the array substrate, thereby improving light utilization. This is not limited here.

[0106] In the above embodiments of the present disclosure, the structure of the display panel is described by taking a quantum dot light-emitting diode (LED) as the light-emitting unit and a quantum dot light-emitting diode (QDLED) display panel as an example. In actual implementation, the display panel in the embodiments of the present disclosure may also be other types of display panels, such as an organic light-emitting diode (OLED) display panel, in which the light-emitting unit may be an OLED. In specific implementations, the structure of the QD LED display panel provided in the embodiments of the present disclosure may be referred to, and is not limited here.

[0107] The present disclosure also provides a display device. The display device includes the display panel provided by any of the aforementioned embodiments. The display device provided by the present disclosure can be a mobile phone, a tablet computer, a laptop computer, a television, a smart wearable device, a display, a monitor, and the like, without limitation herein. The display device provided by the present disclosure, when implemented, has the same or similar technical effects as the display panel provided by any of the aforementioned embodiments, and therefore is not further described herein.

[0108] FIG6 is a flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure.

[0109] The present disclosure also provides a method for manufacturing a display panel. As shown in FIG6 , the method for manufacturing a display panel provided by the present disclosure includes the following steps:

[0110] S610: forming a plurality of conductive bases on one side of the array substrate through a patterning process;

[0111] S620: forming a pixel defining layer on a side of the conductive base facing away from the array substrate;

[0112] S630: etching the pixel defining layer using an etching gas to form openings corresponding to the conductive substrate and exposing the conductive substrate;

[0113] S640: performing surface treatment on the conductive substrate exposed by the opening using an etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer, thereby forming a plurality of first electrodes;

[0114] S650: forming a light-emitting functional layer and a second electrode in sequence on a side of the first electrode facing away from the base substrate to form a light-emitting unit.

[0115] In the method for manufacturing a display panel provided by an embodiment of the present disclosure, after etching a pixel defining layer using an etching gas to form an opening penetrating the pixel defining layer and exposing a conductive substrate, the conductive substrate exposed by the opening is further subjected to surface treatment using the etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer, thereby forming a plurality of first electrodes. The etching gas can be selected based on the work function requirements of the first electrodes after the surface treatment. After the etching gas surface treatment, the work function of the surface of the first electrode facing the pixel defining layer satisfies the requirement that the degree of matching between the hole transmission rate and the electron transmission rate in the light-emitting unit is greater than the degree of matching between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the material of the conductive substrate is directly used as the first electrode. This helps to reduce the difference between the hole transmission rate and the electron transmission rate in the light-emitting unit, reduce non-radiative Auger recombination, and improve the luminous efficiency of the light-emitting unit.

[0116] FIG7 is a second flow chart of a method for manufacturing a display panel according to an embodiment of the present disclosure; FIG8a is one schematic diagram of a manufacturing process of a display panel according to an embodiment of the present disclosure; and FIG8b is a second schematic diagram of a manufacturing process of a display panel according to an embodiment of the present disclosure.

[0117] In some embodiments, the light-emitting unit includes a first light-emitting unit and a second light-emitting unit, wherein the work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is different from the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer. For example, the work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is greater than the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer. For the first light-emitting unit and the second light-emitting unit, different etching gases can be used to etch the pixel defining layer, so that the first electrode of the first light-emitting unit and the first electrode of the second light-emitting unit are surface-treated by different etching gases to obtain different work functions. In specific implementation, as shown in Figure 2, the pixel defining layer is etched by etching gas to form an opening that corresponds to the conductive substrate one by one and exposes the conductive substrate; the conductive substrate exposed by the opening is surface-treated by etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer, thereby forming multiple first electrodes, which specifically includes the following steps:

[0118] S710: forming a first patterned photoresist layer on a side of the pixel defining layer facing away from the conductive substrate; the first patterned photoresist layer includes first etching openings corresponding one-to-one to the first portion of the conductive substrate;

[0119] S720: etching the pixel defining layer exposed by the first etching opening using a first etching gas to form a first partial opening;

[0120] S730: performing a surface treatment reaction on the conductive substrate exposed by the first portion of the opening using a first etching gas, so that the portion of the conductive substrate has a first work function, thereby forming a first portion of the first electrode;

[0121] S740: removing the first patterned photoresist layer and forming a second patterned photoresist layer on a side of the pixel defining layer facing away from the conductive substrate; the second patterned photoresist layer includes second etching openings corresponding to the second portion of the conductive substrate, and the second patterned photoresist layer completely covers the first portion of the openings;

[0122] S750: etching the pixel defining layer exposed by the second etching opening using a second etching gas to form a second partial opening;

[0123] S760: performing a surface treatment reaction on the conductive substrate exposed by the second portion of the opening using a second etching gas, so that the portion of the conductive substrate has a second work function, thereby forming a second portion of the first electrode; the second work function is different from the first work function.

[0124] In a specific implementation, the first light-emitting unit may include a light-emitting unit of at least one color, and the second light-emitting unit may include a light-emitting unit of at least one color. For example, the first light-emitting unit may include a red quantum dot light-emitting diode and a green quantum dot light-emitting diode made of traditional cadmium quantum dot materials, such as CdSe, CdS and other Group II-VI materials, and the second light-emitting unit may include a blue quantum dot light-emitting diode made of traditional cadmium quantum dot materials, such as CdZnSeS quantum dot materials, wherein the first electrodes of the red quantum dot light-emitting diode and the green quantum dot light-emitting diode need to have a higher work function, and the first electrode of the blue quantum dot light-emitting diode needs to have a lower work function. Therefore, during the manufacturing process, after the etching gas used for the red quantum dot light-emitting diode and the green quantum dot light-emitting diode is surface-treated on the first electrode, the first electrode has a higher work function, and after the etching gas used for the blue quantum dot light-emitting diode is surface-treated on the first electrode, the first electrode has a lower work function. In a specific implementation, the first electrodes of the red quantum dot light-emitting diode and the green quantum dot light-emitting diode can be surface-treated at the same time, and the surface treatment of the first electrode of the blue quantum dot light-emitting diode can be performed separately. For example, as shown in Figures 8a and 8b, the production of a display panel may include the following processes:

[0125] 1. As shown in FIG8a , a conductive base layer for forming a conductive base is deposited on the array substrate 100 through a deposition process, and then a plurality of conductive bases 3011 are formed through patterning processes such as exposure and etching. The conductive bases 3011 can also be directly formed on the array substrate 100 through processes such as screen printing, which is not limited here. Specifically, the material used to form the conductive base can be indium tin oxide.

[0126] 2. Form a pixel defining layer 200 on the side of the conductive base 3011 away from the array substrate 100; in specific implementation, the material of the pixel defining layer 200 can be silicon oxide (SiO x ), the pixel definition layer formed by silicon oxide has good gas permeability, which can improve the transmittance of gas products when etching the pixel definition layer 200, and prevent the gas products from being unable to escape inside the pixel definition layer and causing bubbling;

[0127] 3. Forming a first patterned photoresist layer PR1 on a side of the pixel definition layer 200 facing away from the conductive substrate 3011; the first patterned photoresist layer PR1 can be formed on the surface of the pixel definition layer 200 by coating or other methods using an organic material, and then forming a first etching opening K1 corresponding to the first portion of the conductive substrate 3011 on the first patterned photoresist layer PR1 through processes such as exposure and development; wherein the first portion of the conductive substrate 3011 is used to form a first light-emitting unit (including a red quantum dot light-emitting unit and a green quantum dot light-emitting unit), and the first etching opening K1 penetrates the first patterned photoresist layer PR1 and exposes the area of ​​the pixel definition layer 200 to be etched;

[0128] 4. Using a first etching gas g1 to etch the pixel defining layer 200 exposed by the first etching opening K1, a first partial opening K is formed. The first partial opening K penetrates the pixel defining layer 200 and exposes a first portion of the conductive substrate 3011 corresponding thereto. The first partial opening K is used to form a first light-emitting unit. The conductive substrate 3011 exposed by the first partial opening K is then surface-treated by the first etching gas to impart a first work function to the conductive substrate 3011, thereby forming a first portion of the first electrode 301. The first etching gas may be an oxidizing gas mixture to increase the work function of the surface of the first electrode. In a specific implementation, the first etching gas comprises CF4 and O2. During the etching and surface treatment process, the flow rate of CF4 is approximately 400 sccm, and the flow rate of O2 is approximately 80 sccm. The total etching and surface treatment time is approximately 61 s. The work function of the surface of the first electrode after treatment is 4.8 eV to 5.3 eV.

[0129] 5. As shown in FIG8b , after the surface treatment of the first electrode 301 of the first portion is completed, the first patterned photoresist layer is removed, and then a second patterned photoresist layer PR2 is formed on the side of the pixel defining layer 200 away from the conductive substrate. The second patterned photoresist layer PR2 can be formed on the surface of the pixel defining layer 200 by coating or other methods using an organic material. Then, through processes such as exposure and development, a second etching opening K2 corresponding to the second portion of the conductive substrate 3011 is formed on the second patterned photoresist layer PR2. The second portion of the conductive substrate 3011 is used to manufacture the second light-emitting unit (blue quantum dot light-emitting unit). The second etching opening K2 penetrates the second patterned photoresist layer PR2 and exposes the area of ​​the pixel defining layer 200 to be etched. The second patterned photoresist layer PR2 also completely covers the first portion of the opening K to protect the first electrode exposed by the first portion of the opening K.

[0130] 6. A second etching gas g2 is used to etch the pixel defining layer 200 exposed by the second etching opening K2 to form a second partial opening K. The second partial opening K penetrates the pixel defining layer 200 and exposes a corresponding second portion of the conductive substrate 3011. The second partial opening K is used to form a second light-emitting unit. The conductive substrate 3011 exposed by the second partial opening K is then surface-treated by the second etching gas to impart a second work function to the conductive substrate 3011, thereby forming a second portion of the first electrode 301. The second etching gas may be a reducing gas mixture to reduce the work function of the surface of the first electrode. In a specific implementation, the second etching gas comprises CHF3, Ar, and H2. During the etching and surface treatment process, the flow rate of CHF3, the flow rate of Ar, and the flow rate of H2 are approximately 200 sccm, respectively, and the flow rate of H2 are approximately 25 sccm. The total duration of the etching and surface treatment is approximately 104 s. The work function of the surface of the first electrode after treatment is 4.0 eV to 4.2 eV.

[0131] 7. After the surface treatment of the first electrode is completed, the second patterned photoresist layer is removed, and the light-emitting functional layer, the second electrode and other film layers are sequentially manufactured to complete the manufacture of the light-emitting unit 300 and the display panel.

[0132] Figures 8a and 8b illustrate the method for manufacturing the display panel provided by the embodiment of the present disclosure by taking the simultaneous surface treatment of the first electrodes of the red light-emitting unit and the green light-emitting unit as an example. In some embodiments, the first electrodes of the red light-emitting unit and the green light-emitting unit can also be surface-treated separately using different etching gases. The treatment process can refer to the blue light-emitting unit and will not be repeated here.

[0133] The quantum dot material disclosed herein may include a quantum dot body and a quantum dot ligand structure, wherein the quantum dot body and the coordination group in the quantum dot ligand are connected by a chemical bond. The quantum dot body may include any of: Group IIB-VIA quantum dots, Group IIIA-VA quantum dots, Group IVA-VIA quantum dots, core-shell quantum dots, and ABX3 type perovskite quantum dots. In ABX3 type perovskite quantum dots, A is CH3NH3 + (methylamine), NH2CH=NH2(formamidine) and Cs + One or more of, B is Pb 2+ and Sn 2+ One or two of the following, X is Cl - Br - and I - One or more of the ABX3 type perovskite quantum dots include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3 and CsPbI3.

[0134] Exemplarily, the IIB-VIA group quantum dots are selected from: binary compounds such as one or more of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZn Te, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or mixtures thereof; and quaternary compounds such as HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, or mixtures thereof, but are not limited thereto.

[0135] The IIIA-VA group quantum dots are selected from: binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or mixtures thereof; ternary compounds such as GaNPs, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InNPs, InNAs, InNSb, InPAs, InPSb, or mixtures thereof; and quaternary compounds such as GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNPs, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNPs, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or mixtures thereof, but are not limited thereto.

[0136] Group IVA-VIA quantum dots are selected from, but are not limited to, binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, or mixtures thereof; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, or mixtures thereof; and quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, or mixtures thereof. Group IVA-VIA quantum dots are selected, for example, from elemental (mono) semiconductors such as Si, Ge, or mixtures thereof; and binary semiconductor compounds such as SiC, SiGe, and mixtures thereof.

[0137] Core-shell quantum dots are structures where one material is the core and the other is the shell. For example, a CdS / ZnS quantum dot is a quantum dot where the core is CdS and the shell is ZnS.

[0138] In some other embodiments, the quantum dot bodies may be other nanoscale materials, such as nanorods, nanosheets, etc. The components of other nanoscale materials may include 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.

[0139] For example, the quantum dot body can include cadmium (Cd)-free quantum dots. Cadmium-free quantum dots are quantum dots that do not include cadmium (Cd). Cadmium (Cd) can cause serious environmental / health problems, so non-cadmium-based quantum dots can be effectively used.

[0140] In the method for manufacturing a display panel provided in the embodiments of the present disclosure, the first electrode can serve as either the anode or the cathode of a light-emitting unit. Taking a quantum dot light-emitting diode display panel as an example, when the first electrode serves as the anode of the light-emitting unit, a light-emitting functional layer and a second electrode are sequentially fabricated on the side of the first electrode facing away from the substrate to form the light-emitting unit. The method specifically includes the following steps:

[0141] 1. After the first electrode has been surface treated, clean the array substrate. In practice, use deionized water to clean it for 10 minutes, then replace the deionized water and clean it for another 10 minutes. Then, blow nitrogen to dry the water film on the substrate surface and bake it in an oven or on a heating platform at 100°C to 150°C for about 5 minutes.

[0142] 2. Forming a hole injection layer in the opening of the pixel defining layer by spin coating, slit coating, doctor blading, inkjet printing, evaporation, or other processes; the hole injection layer can be made of materials such as PEDOT:PSS, NiO, and MoO3, without limitation; taking PEDOT:PSS as an example, the thickness of the hole injection layer is about 15 to 40 nm. After the hole injection layer is formed, it is baked at a temperature of 150°C for 10 to 30 minutes;

[0143] 3. Forming a hole transport layer on the side of the hole transport layer facing away from the first electrode by spin coating, slit coating, doctor blade coating, inkjet printing, evaporation, or other processes; the hole transport layer can be made of materials such as TFB, PF8Cz, and PVK, without limitation; taking TFB as an example, the thickness of the hole transport layer is about 15 nm to 40 nm. After the hole transport layer is formed, it is baked at 130°C for 20 nm to 30 min;

[0144] 4. Using a photolithography patterning process or inkjet printing method, a quantum dot light-emitting layer is formed in the opening of the pixel defining layer; quantum dot light-emitting layers of different colors are respectively formed in the corresponding openings; in a specific implementation, the quantum dot light-emitting layer may include a red quantum dot light-emitting layer, a green quantum dot light-emitting layer, and a blue quantum dot light-emitting layer, wherein the red quantum dot light-emitting diode and the green quantum dot light-emitting diode are each formed in the opening corresponding to the first electrode having a first work function, and the blue quantum dot light-emitting diode is formed in the opening corresponding to the first electrode having a second work function; the thickness of the quantum dot light-emitting layer is about 10nm to 30nm;

[0145] 6. An electron transport layer is formed on the side of the quantum dot light-emitting layer facing away from the hole transport layer. The material of the electron transport layer can be ZnO or ZnMgO, etc., which are not limited here. The thickness of the electron transport layer is about 30nm to 90nm. After the electron transport layer is formed, it is baked at a temperature of 80℃ to 120℃ for about 10 minutes.

[0146] 7. The substrate is introduced into the evaporation machine, and a cathode is deposited on the side of the electron transport layer away from the quantum dot light-emitting layer to form a light-emitting unit; the cathode can be an aluminum electrode, and the evaporation rate of the electrode material during evaporation is about The thickness of the aluminum electrode is about 100 nm, which is not limited here.

[0147] Taking a quantum dot light-emitting diode display panel as an example, when the first electrode serves as the cathode of a light-emitting unit, a light-emitting functional layer and a second electrode are sequentially fabricated on the side of the first electrode facing away from the substrate to form a light-emitting unit. The steps specifically include:

[0148] 1. After the first electrode has been surface treated, clean the array substrate. In practice, use deionized water to clean it for 10 minutes, then replace the deionized water and clean it for another 10 minutes. Then, blow nitrogen to dry the water film on the substrate surface and bake it in an oven or on a heating platform at 100°C to 150°C for about 5 minutes.

[0149] 2. An electron transport layer is formed in the opening of the pixel defining layer. The material of the electron transport layer can be ZnO or ZnMgO, etc., which is not limited here. The thickness of the electron transport layer is about 30nm to 90nm. After the electron transport layer is formed, it is baked at a temperature of 80°C to 120°C for about 10 minutes.

[0150] 3. Using a photolithography patterning process or inkjet printing method, a quantum dot light-emitting layer is formed in the opening of the pixel defining layer; quantum dot light-emitting layers of different colors are respectively produced in the corresponding openings; in a specific implementation, the quantum dot light-emitting layer may include a red quantum dot light-emitting layer, a green quantum dot light-emitting layer, and a blue quantum dot light-emitting layer, wherein the red quantum dot light-emitting diode and the green quantum dot light-emitting diode are each formed in the opening corresponding to the first electrode having a first work function, and the blue quantum dot light-emitting diode is formed in the opening corresponding to the first electrode having a second work function; the thickness of the quantum dot light-emitting layer is about 10nm to 30nm;

[0151] 4. The substrate is introduced into an evaporation machine, and a hole transport layer and a hole injection layer are sequentially prepared on the side of the quantum dot light-emitting layer away from the electron transport layer; wherein the hole transport layer may include TCTA with a thickness of 2nm to 20nm and NPB with a thickness of 10nm to 50nm as a double hole transport layer, and the hole injection layer may include MoO3 with a thickness of 2nm to 20nm; in specific implementation, the thickness of TCTA may be 5nm to 10nm, the thickness of NPB may be 20nm to 30nm, and the thickness of MoO3 may be 5nm to 10nm, which are not limited here;

[0152] 5. Evaporate the anode on the side of the hole injection layer away from the quantum dot light-emitting layer to form a light-emitting unit; the anode can be a silver electrode, and the evaporation rate of the electrode material during evaporation is about The thickness of the silver electrode is about 100 nm, which is not limited here.

[0153] In some embodiments, after the light emitting unit of the display panel is manufactured, an encapsulation layer may be formed on the side of the light emitting unit away from the array substrate to protect the light emitting unit. The encapsulation layer may be a thin film encapsulation structure, for example, including at least one layer of SiO x , SiON or SiN x Inorganic thin film; In a specific implementation, the encapsulation layer can adopt a sandwich structure, for example, a structure in which a layer of organic thin film is disposed between two layers of inorganic thin film. In some embodiments, the encapsulation layer can also be a glass cover plate, which is encapsulated by attaching with UV-curable adhesive, but this is not limited here.

[0154] The specific structure of the display panel provided in the embodiment of the present disclosure has been described in detail in the foregoing content. For specific implementation, the specific content included in the method for manufacturing the display panel provided in the embodiment of the present disclosure can also refer to the specific structure of the display panel provided in the foregoing content, and will not be repeated here.

[0155] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present disclosure.

[0156] Obviously, those skilled in the art may make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is intended to include these modifications and variations.

Claims

1. A display panel comprising an array substrate and a pixel defining layer located on one side of the array substrate, wherein the pixel defining layer comprises a plurality of openings, wherein: Also includes: A plurality of light-emitting units are located in the openings in a one-to-one correspondence; The light emitting unit includes a first electrode, and the first electrode is electrically connected to the array substrate; The first electrode includes a conductive matrix and an impurity element doped in the conductive matrix; the impurity element is also doped in the side wall of the opening of the pixel defining layer; the work function of the surface of the first electrode facing the pixel defining layer satisfies the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit, which is greater than the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the material of the conductive matrix is directly used as the first electrode.

2. The display panel according to claim 1, wherein: The multiple light-emitting units include a first light-emitting unit and a second light-emitting unit; the work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is greater than the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer.

3. The display panel according to claim 2, wherein: The work function of the surface of the first electrode of the first light-emitting unit facing the pixel defining layer is greater than the work function of the material of the conductive substrate; the work function of the surface of the first electrode of the second light-emitting unit facing the pixel defining layer is smaller than the work function of the material of the conductive substrate.

4. The display panel according to claim 3, wherein: The light-emitting unit further includes a light-emitting functional layer and a second electrode stacked in sequence on a side of the first electrode facing away from the array substrate; The light-emitting functional layer includes a quantum dot light-emitting layer; The first light-emitting unit includes a red light-emitting unit and a green light-emitting unit; the quantum dot light-emitting layer of the red light-emitting unit includes a red quantum dot light-emitting material; the quantum dot light-emitting layer of the green light-emitting unit includes a green quantum dot light-emitting material; The second light-emitting unit is a blue light-emitting unit; the quantum dot light-emitting layer of the blue light-emitting unit includes a blue quantum dot light-emitting material.

5. The display panel according to claim 3, wherein: A content of defective oxygen on a surface of the first electrode of the first light-emitting unit facing the pixel defining layer is smaller than a content of defective oxygen on a surface of the first electrode of the second light-emitting unit facing the pixel defining layer.

6. The display panel according to any one of claims 1 to 5, wherein: The doping elements in the first electrode are concentrated on a side of the conductive substrate close to the pixel defining layer.

7. The display panel according to claim 6, wherein: The thickness of the first electrode is 60 nm to 100 nm; the thickness of the doping elements concentrated in the conductive matrix is less than or equal to 20 nm.

8. The display panel according to any one of claims 1 to 7, wherein: The material of the pixel defining layer is an inorganic material containing silicon.

9. The display panel according to any one of claims 1 to 7, wherein: The doping element includes at least fluorine.

10. The display panel according to claim 9, wherein: The material of the pixel defining layer is silicon oxide. 11 . The display panel according to claim 1 , wherein a material of the conductive substrate comprises indium tin oxide.

12. The display panel according to any one of claims 1 to 11, wherein: The sheet resistance of the first electrode is greater than the sheet resistance of the material of the conductive substrate.

13. The display panel according to any one of claims 1 to 12, wherein: The first electrode is the anode of the light emitting unit.

14. The display panel according to any one of claims 1 to 12, wherein: The first electrode is the cathode of the light emitting unit.

15. A display device, wherein: The display panel comprises the display panel according to any one of claims 1 to 14.

16. A method for manufacturing a display panel, wherein: include: forming a plurality of conductive bases on one side of the array substrate through a patterning process; The conductive base is electrically connected to the array substrate; forming a pixel defining layer on a side of the conductive base facing away from the array substrate; The pixel defining layer is etched by etching gas to form a one-to-one correspondence with the conductive substrate, and an opening exposing the conductive substrate; The conductive substrate exposed by the opening is subjected to surface treatment by the etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer, thereby forming a plurality of first electrodes; the work function of the surface of the first electrode facing the pixel defining layer satisfies the requirement that the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit is greater than the matching degree between the hole transmission rate and the electron transmission rate in the light-emitting unit in which the material of the conductive substrate is directly used as the first electrode; A light-emitting functional layer and a second electrode are sequentially formed on a side of the first electrode facing away from the base substrate to form a light-emitting unit.

17. The method of claim 16, wherein: The pixel defining layer is etched by an etching gas to form openings corresponding to the conductive substrate and exposing the conductive substrate; The method further comprises: performing surface treatment on the conductive substrate exposed by the opening by using the etching gas to change the work function of the surface of the conductive substrate facing the pixel defining layer to form a plurality of first electrodes. forming a first patterned photoresist layer on a side of the pixel defining layer facing away from the conductive substrate; the first patterned photoresist layer includes first etching openings corresponding one-to-one to the first portion of the conductive substrate; Etching the pixel defining layer exposed by the first etching opening using a first etching gas to form a first portion of the opening; Performing surface treatment on the conductive substrate exposed by the first portion of the opening using a first etching gas, so that the conductive substrate has a first work function, thereby forming a first portion of the first electrode; removing the first patterned photoresist layer and forming a second patterned photoresist layer on a side of the pixel defining layer facing away from the conductive substrate; the second patterned photoresist layer includes second etching openings corresponding one-to-one to the second portion of the conductive substrate, and the second patterned photoresist layer completely covers the openings in the first portion; The pixel defining layer exposed by the second etching port is etched by a second etching gas to form the opening described in the second part; The conductive substrate exposed by the second portion of the opening is surface-treated by a second etching gas to provide the conductive substrate with a second work function, thereby forming a second portion of the first electrode; the second work function is different from the first work function.

18. The method of claim 17, wherein: The first etching gas is an oxidizing gas mixture; the second etching gas is a reducing gas mixture.

19. The method of claim 18, wherein: Components of the first etching gas include CF4 and O2; components of the second etching gas include CHF3, Ar and H2.

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