CN111477661B

CN111477661B - Display substrate, preparation method and display device

Info

Publication number: CN111477661B
Application number: CN202010301289.6A
Authority: CN
Inventors: 贾文斌; 叶志杰; 万想; 马凯葓; 朱飞飞
Original assignee: BOE Technology Group Co Ltd; Hefei BOE Zhuoyin Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Hefei BOE Zhuoyin Technology Co Ltd
Priority date: 2020-04-16
Filing date: 2020-04-16
Publication date: 2023-04-14
Anticipated expiration: 2040-04-16
Also published as: CN111477661A

Abstract

The invention provides a display substrate, a preparation method and a display device, belongs to the technical field of display, and can solve the problem that climbing height of each organic functional layer in the existing display substrate is too high or too low. The display substrate of the present invention includes: the pixel structure comprises a substrate and a pixel limiting layer positioned on the substrate; the pixel defining layer includes: the pixel structure comprises a plurality of pixel retaining walls and accommodating parts defined by the pixel retaining walls; the display substrate further includes: a plurality of organic functional layers formed in the receiving portion; and in the direction of deviating from the substrate, the climbing height of the (N + 1) th organic functional layer on the side surface of the pixel retaining wall is at least equal to the climbing height of the nth organic functional layer on the side surface of the pixel retaining wall, and N is a positive integer.

Description

Display substrate, preparation method and display device

Technical Field

The invention belongs to the technical field of display, and particularly relates to a display substrate, a preparation method and a display device.

Background

Organic Light-Emitting diodes (OLEDs) have been widely used in the display field due to their advantages of high brightness and high reliability. The film forming method of OLED mainly includes evaporation process and solution process. At present, the evaporation process technology is applied to mass production, but the technology has expensive materials and low material utilization rate, and the cost of product development is increased. In the solution process technology, the OLED film forming method mainly comprises ink-jet printing, nozzle coating, spin coating, screen printing and the like.

The inventor finds that at least the following problems exist in the prior art: when an ink-jet printing method is adopted to form an organic functional layer in an OLED, a pixel defining structure needs to be manufactured on an electrode of a substrate in advance so as to limit ink drops to accurately flow into a specified R/G/B sub-pixel area. The volume of the ink drop that present pixel's internal volume can allow all is less than the thick volume of device membrane, leads to filling up the pixel hole at the printing in-process ink drop, and in drying process, because present pixel is injectd the structure and only has the top hydrophobicity, leads to the ink drop at pixel barricade lateral wall climbing, and the size of climbing degree leads to material utilization to hang down, and the membrane thickness is difficult to control, leads to effectual luminous zone to diminish easily, and the life-span shortens, photochromic worsens scheduling problem. If the coverage climbing between the film layers is serious, the utilization rate of ink drop materials is low, and waste is easily caused. If the coverage between the film layers climbs poorly, a De-wetting phenomenon is easily generated, which causes the defects that the pixel is not bright or relatively dark, and the like.

Disclosure of Invention

The present invention is directed to at least one of the technical problems of the prior art, and provides a display substrate, a manufacturing method thereof, and a display device.

The technical scheme adopted for solving the technical problem of the invention is a display substrate, which comprises: the pixel structure comprises a substrate and a pixel defining layer positioned on the substrate; the pixel defining layer includes: the pixel structure comprises a plurality of pixel retaining walls and accommodating parts defined by the pixel retaining walls; the display substrate further includes: a plurality of organic functional layers formed in the receiving portion;

along deviating from on the base direction, the (N + 1) th layer organic functional layer is in climbing height on the pixel barricade side equals the (N) th layer at least organic functional layer is in climbing height on the pixel barricade side, N is the positive integer.

Optionally, the organic functional layer comprises: a hole injection layer, a hole transport layer and a light emitting layer;

the ratio of the climbing height of the light-emitting layer on the side face of the pixel retaining wall to the climbing height of the hole transport layer on the side face of the pixel retaining wall is 1-1.2;

the hole transport layer is in the climbing height of pixel barricade side with the hole injection layer is in the ratio of the climbing height of pixel barricade side is 1 to 1.2.

Optionally, a ratio of a height of the pixel retaining wall to a climbing height of the hole injection layer on the side of the pixel retaining wall is greater than or equal to 12.5.

Optionally, the height of the pixel retaining wall is 1.0 micrometer to 1.5 micrometers.

Optionally, the display substrate further comprises: a reflective electrode corresponding to the housing portion;

the reflective electrode is located between the substrate and the hole injection layer.

Optionally, the display substrate further comprises: a lyophobic functional layer;

the lyophobic functional layer is located one side of the pixel retaining wall deviating from the substrate.

The technical scheme adopted for solving the technical problem of the invention is a display device which comprises the display substrate.

The technical scheme adopted for solving the technical problem of the invention is a preparation method of a display substrate, which comprises the following steps:

forming a plurality of pixel retaining walls and accommodating parts on the substrate;

sequentially forming a plurality of organic functional layers in the accommodating portion by an inkjet printing process;

along deviating from on the base direction, the (N + 1) th layer the organic functional layer is in climbing height on the pixel barricade side equals the nth layer at least the organic functional layer is in climbing height on the pixel barricade side, N is the positive integer.

Optionally, the multiple organic functional layers in the accommodating portion sequentially through an inkjet printing process include:

dropping a first mixed solution formed by mixing first conductive ink and a first solvent into the accommodating part, and forming a hole injection layer through vacuum drying;

dropping a second mixed solution formed by mixing second conductive ink and a second solvent onto the hole injection layer, and forming a hole transport layer through vacuum drying;

dropping a third mixed solution formed by mixing a third conductive ink and a third solvent onto the hole transport layer, and forming a light emitting layer through vacuum drying;

wherein the surface tension of the first solvent is less than the surface tension of the second solvent, and the surface tension of the second solvent is less than the surface tension of the third solvent.

Optionally, the first solvent comprises: at least one of cyclohexylbenzene, carbonate, an alkylaromatic hydrocarbon and an aromatic hydrocarbon;

the second solvent includes: at least one of aromatic ester, 4-methylanisole and toluene;

the third solvent includes: 1, 3-dimethyl-2-imidazolidinone, diethylene glycol, 2- (2-methoxyethoxy) ethanol.

Drawings

FIG. 1 is a schematic diagram of a display substrate in the prior art;

fig. 2 and fig. 3 are schematic partial structural diagrams of a display substrate in the prior art;

fig. 4 is a schematic structural diagram of a display substrate according to an embodiment of the present invention;

fig. 5 and fig. 6 are schematic partial structural diagrams of a display substrate according to an embodiment of the present invention;

fig. 7 is a schematic flow chart illustrating a method for manufacturing a display substrate according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item preceding the word comprises the element or item listed after the word and its equivalent, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

The display substrate referred to below may be an OLED display substrate, and the OLED device may be a pixel unit in the display substrate. Generally, an OLED device includes at least first and second electrodes disposed opposite to each other, and a plurality of organic functional layers sandwiched between the first and second electrodes; one of the first electrode and the second electrode is an anode, and the other is a cathode, and the first electrode is an anode and the second electrode is a cathode in the following description. In practical applications, the organic functional layer in the OLED device can be prepared by an inkjet printing process. In the preparation process, a pixel limiting layer is used for limiting a region formed by a pixel unit, mixed solution of conductive ink, organic solvent and the like is dripped into the limiting region, and an organic functional layer with a certain film thickness is formed through a vacuum drying process to form the OLED device.

Fig. 1 is a schematic structural diagram of a display substrate in the prior art, as shown in fig. 1, the display substrate includes: a substrate 101 and a pixel defining layer 102 on the substrate 101; the pixel defining layer 102 includes: a plurality of pixel barriers 1021 and a receiving part 1022 defined by the pixel barriers 1021; the display substrate further includes: a plurality of organic functional layers formed in the receiving part 1022. At present, the pixel barriers 1021 are generally formed by an organic photoresist through a photolithography process, and in order to ensure that the conductive liquid drop and the organic solvent dropped into the accommodating portion 1022 defined by the pixel barriers 1021 can be spread sufficiently, the side surfaces of each pixel barrier 1021 need to have a certain hydrophilicity, and particularly, the hydrophilicity is stronger at the portion closer to the substrate 101. Like this, in the vacuum drying process, each layer of organic functional layer of formation all can climb to the direction of keeping away from base 101 under the hydrophilic effect of pixel barricade 1021 to the climbing height is difficult to control, leads to each layer of organic functional layer climbing height too high or climbing height to hang down excessively. As shown in fig. 2, if the climbing height is too high, the utilization rate of the conductive ink and the organic solvent is low, and the uniformity of the organic functional layer is affected, thereby affecting the display effect. As shown in fig. 3, if the climbing height is too low, the organic functional layer far from the substrate 101 in the adjacent organic functional layers cannot completely cover the organic functional layer near the substrate 101, so that a non-wetting (De-wetting) phenomenon is easily generated, which easily causes the poor brightness or darkness of the OLED device in the display substrate, and affects the display effect. In order to solve the technical problems in the prior art, embodiments of the present invention provide a display substrate, a manufacturing method thereof, and a display device. The display substrate, the manufacturing method thereof, and the display device provided by the embodiments of the present invention will be described in further detail with reference to the following detailed description and the accompanying drawings.

Example one

Fig. 4 is a schematic structural diagram of a display substrate according to an embodiment of the present invention, and as shown in fig. 4, the display substrate includes: a substrate 101, and a pixel defining layer 102 on the substrate 101; the pixel defining layer 102 includes: a plurality of pixel barriers 1021 and an accommodating part 1022 defined by the pixel barriers 1021; the display substrate further includes: a plurality of organic functional layers formed in the accommodating part 1022; along deviating from the basement 101 direction, the climbing height of the (N + 1) th layer of organic functional layer on the pixel barricade 1021 side is at least equal to the climbing height of the nth layer of organic functional layer on the pixel barricade 1021 side, and N is a positive integer.

In the display substrate provided in the embodiment of the present invention, along the direction departing from the substrate 101, the climbing height of the N +1 th organic functional layer on the side surface of the pixel retaining wall 1021 is at least equal to the climbing height of the N th organic functional layer on the side surface of the pixel retaining wall 1021, that is, as shown in fig. 5, among the adjacent organic functional layers, the climbing height of the organic functional layer far from the substrate 101 on the side surface of the pixel retaining wall 1021 is slightly greater than that of the organic functional layer close to the substrate 101, and the climbing height difference between the two is much smaller than that in the prior art, or as shown in fig. 6, the climbing heights of the organic functional layers far from the substrate 101 on the side surface of the pixel retaining wall 1021 are equal and parallel to each other. Therefore, on the premise that the phenomenon that each film layer is not wetted (De-wetting) in the vacuum drying process can be avoided, the material utilization rate can be improved to the maximum extent, the effective aperture opening ratio of the OLED device is improved, the performance of the OLED device is improved, and the display effect of the display substrate is improved.

In some embodiments, as shown in fig. 5 and 6, the organic functional layer includes: a hole injection layer 1031, a hole transport layer 1032, and a light emitting layer 1033; the ratio of the climbing height of the light emitting layer 1033 at the side of the pixel retaining wall 1021 to the climbing height of the hole transport layer 1032 at the side of the pixel retaining wall 1021 is 1 to 1.2; the ratio of the climbing height of the hole transport layer 1032 at the side of the pixel retaining wall 1021 to the climbing height of the hole injection layer 1031 at the side of the pixel retaining wall 1021 is 1 to 1.2.

It should be noted that the organic functional layers in the OLED device may include a hole injection layer 1031, a hole transport layer 1032, and a light emitting layer 1033, which are sequentially disposed on the substrate 101. The light emitting layer 1033 may wrap the hole transport layer 1032 just below it, the hole transport layer 1032 may wrap the hole injection layer 1031 just below it, or a portion of the light emitting layer 103 climbing over the side surface of the pixel retaining wall 1021, a portion of the hole transport layer 1032 climbing over the side surface of the pixel retaining wall 1021, and a portion of the hole injection layer 1031 climbing over the side surface of the pixel retaining wall 1021 are parallel to each other. In practical application, the climbing height of each film layer can be controlled by reasonably selecting the material and dosage of each film layer. Therefore, on the premise that the phenomenon that each film layer is not wetted (De-wetting) in the vacuum drying process can be avoided, the material utilization rate can be improved to the maximum extent, the effective aperture opening ratio of the OLED device is improved, the performance of the OLED device is improved, and the display effect of the display substrate is improved.

In some embodiments, a ratio of a height of the pixel wall 1021 to a climbing height of the hole injection layer 1031 on a side of the pixel wall 1021 is greater than or equal to 12.5.

It should be noted that, in the embodiment of the present invention, the height of the pixel retaining wall 1021 is much greater than the climbing height of the hole injection layer 1031 on the side of the pixel retaining wall 1021, so that the accommodating portion 1022 defined by the pixel retaining wall 1021 has a larger volume to carry sufficient amount of conductive ink and organic solvent to form each film layer with a certain thickness, and the height of the pixel retaining wall 1021 can be reasonably controlled according to actual needs.

In some embodiments, the height of the pixel walls 1021 is 1.0 micron to 1.5 microns.

It should be noted that the height of the pixel barriers 1021 may be 1.0 to 1.5 microns, so as to ensure that the accommodating portion 1022 defined by the pixel barriers 1021 has a larger solvent to carry sufficient amount of the conductive ink and the organic solvent to form a certain thickness of each film.

In some embodiments, as shown in fig. 4, the display substrate further includes: a reflective electrode 104 corresponding to the accommodation part 1022; the reflective electrode 104 is located between the substrate 101 and the hole injection layer 1031.

The organic functional layers such as the hole injection layer 1031, the hole transport layer 1032 and the light emitting layer 1033 may be located on the reflective electrode 104 formed in the accommodating portion 1022, the reflective electrode 104 may be connected to a pixel driving circuit in the display substrate, and may be made of materials such as Indium Tin Oxide (ITO), indium Zinc Oxide (IZO) and zinc oxide (ZnO), and the pixel driving circuit may provide a pixel driving signal. In practical applications, the reflective electrode 104 can be multiplexed as an anode of the OLED device, and can reflect the light generated by the light-emitting layer 1033 to a side away from the substrate 101 while transmitting the pixel driving signal, so as to form a reflective OLED device. The material of the light emitting layer 1033 may include a small molecule organic material or a polymer molecule organic material to form a conductive ink material, may be a fluorescent light emitting material or a phosphorescent light emitting material, may emit red light, green light, blue light, or may emit white light, etc. The hole injection layer 1031 and the hole transport layer 1032 may also comprise conductive ink materials formed of other small molecule organic materials or polymer molecule organic materials, and may generate holes and transport the holes into the light emitting layer 1033 under the control of a voltage signal applied from the anode. According to different practical needs, in different embodiments, the OLED device may further include film layers such as an electron transport layer, an electron injection layer, and a cathode. The cathode may be made of a metal material such as lithium (Li), aluminum (Al), magnesium (Mg), or silver (Ag) and covers the electron injection layer. The pixel defining layer 102 may be covered with a planarization layer to planarize the first pixel retaining wall 1021 for adhesion with other layers thereon in practical applications. In addition, it should be noted that the anodes of the OLED devices may be independent from each other, and the cathodes of the OLED devices may be connected over the entire surface; that is, the cathode may be a full-area electrode structure disposed on the display substrate, and may be used for a common electrode of a plurality of OLED devices.

In some embodiments, as shown in fig. 4, the display substrate further includes: a lyophobic functional layer 105; the lyophobic function layer 105 is located on a side of the pixel retaining wall 1021 facing away from the substrate 101.

It should be noted that the lyophobic function layer 105 may have a strong hydrophobic property, so as to ensure that the conductive ink and the organic solvent dropped into the accommodating portion 1022 are well spread, and at the same time, the lyophobic function layer may be limited in the area where the accommodating portion 1022 is located without overflowing, thereby preventing the conductive ink and the organic solvent in the adjacent accommodating portion 1022 from being contaminated with each other, and thus improving the yield of products. Generally, on the 1 μm pixel retaining wall 1021, the thickness of the lyophobic functional layer 105 is 50 nm, and the thickness of the hydrophobic functional layer 105 can be controlled according to actual needs.

In some embodiments, the substrate 101 may be a flexible substrate to improve the flexibility of the display substrate, so that the display substrate can be bendable, and the like, so as to expand the application range of the display substrate; but not limited thereto, the substrate 101 may also be configured to be rigid, and the specific performance of the substrate 101 may be determined according to the actual requirements of the display product. In addition, the substrate 101 may have a single-layer structure or a multi-layer structure. For example, the substrate 101 may include a plurality of film layers, such as a polyimide layer, a buffer layer, and a polyimide layer, which are sequentially stacked, where the buffer layer may be made of silicon nitride, silicon oxide, or other materials, so as to achieve the effects of blocking water and oxygen and blocking alkali ions; it should be noted that the structure of the substrate 101 is not limited thereto, and may be determined according to actual requirements.

It can be understood that the display substrate provided in the embodiment of the present invention may further include other film layers such as a driving circuit layer, an interlayer dielectric layer, a passivation layer, and an encapsulation layer, in addition to the above film layer structures. The above-mentioned film layers can be formed by using the preparation method in the prior art, and the functions and the implementation principle thereof are similar to those in the prior art, and are not described herein again.

Example two

Based on the same inventive concept, an embodiment of the present invention provides a display device, which includes the display substrate provided in the above embodiment, and the display device may be an electronic device having a display substrate, such as a mobile phone, a tablet computer, an electronic watch, a sports bracelet, and a notebook computer. The implementation principle of the display device can refer to the above discussion of the implementation principle of the display substrate, and is not repeated herein.

In the organic functional layers adjacent to the display substrate of the display device provided by the embodiment of the invention, the climbing height of the organic functional layer far away from the substrate on the side surface of the pixel retaining wall is slightly larger than that of the organic functional layer close to the substrate, and the climbing height difference between the organic functional layer far away from the substrate and the organic functional layer is much smaller than that of the organic functional layer close to the substrate in the prior art, or the climbing heights of the organic functional layer far away from the substrate on the side surface of the pixel retaining wall are equal and are parallel. Therefore, on the premise that the phenomenon that each film layer is not wetted (De-wetting) in the vacuum drying process can be avoided, the material utilization rate can be improved to the maximum extent, the effective aperture opening ratio of the OLED device is improved, the performance of the OLED device is improved, and the display effect of the display substrate is improved.

EXAMPLE III

Based on the same inventive concept, an embodiment of the present invention provides a method for manufacturing a display substrate, fig. 7 is a schematic flow chart of the method for manufacturing the display substrate according to the embodiment of the present invention, and as shown in fig. 7, the method for manufacturing the display substrate includes the following steps:

s701, forming a plurality of pixel retaining walls and accommodating parts on the substrate.

S702, sequentially forming a plurality of organic functional layers in the accommodating part through an ink-jet printing process; and in the direction of deviating from the substrate, the climbing height of the (N + 1) th organic functional layer on the side surface of the pixel retaining wall is at least equal to the climbing height of the nth organic functional layer on the side surface of the pixel retaining wall, and N is a positive integer.

In the method for manufacturing a display substrate according to the embodiment of the present invention, a plurality of organic functional layers may be formed in the accommodating portion through an inkjet printing process, and a climbing height of the (N + 1) th organic functional layer on the side surface of the pixel retaining wall is at least equal to a climbing height of the nth organic functional layer on the side surface of the pixel retaining wall along a direction away from the substrate, that is, in adjacent organic functional layers, a climbing height of the organic functional layer far from the substrate on the side surface of the pixel retaining wall is slightly greater than that of the organic functional layer close to the substrate, and a climbing height difference between the organic functional layer far from the substrate and the organic functional layer close to the substrate is much smaller than that in the prior art, or climbing heights of the organic functional layers far from the substrate on the side surface of the pixel retaining wall are equal and parallel to each other. Therefore, on the premise that the phenomenon that each film layer is not wetted (De-wetting) in the vacuum drying process can be avoided, the material utilization rate can be improved to the maximum extent, the effective aperture opening ratio of the OLED device is improved, the performance of the OLED device is improved, and the display effect of the display substrate is improved.

In some embodiments, the step S702, sequentially depositing a plurality of organic functional layers in the receiving portion through an inkjet printing process, includes:

s7021, a first mixed solution in which the first conductive ink and the first solvent are mixed is dropped into the accommodating portion, and a hole injection layer is formed by vacuum drying.

S7022, a second mixed solution formed by mixing the second conductive ink and the second solvent is dropped onto the hole injection layer, and vacuum-dried to form the hole transport layer.

S7023, dropping a third mixed solution formed by mixing a third conductive ink and a third solvent onto the hole transport layer, and vacuum drying to form a light emitting layer; wherein the surface tension of the first solvent is less than the surface tension of the second solvent, and the surface tension of the second solvent is less than the surface tension of the third solvent.

The first solvent, the second solvent, and the third solvent have different surface tension capacities, and the surface tension of the first solvent is smaller than the surface tension of the second solvent, and the surface tension of the second solvent is smaller than the surface tension of the third solvent. Therefore, in the vacuum drying process, the adsorption force between the formed hole injection layer and the pixel retaining wall is smaller than that between the hole transport layer and the pixel retaining wall, and the adsorption force between the hole transport layer and the pixel retaining wall is smaller than that between the light emitting layer and the pixel retaining wall, so that the climbing height of the hole injection layer on the side surface of the pixel retaining wall is smaller than that of the hole transport layer on the pixel retaining wall, and the climbing height of the hole transport layer on the pixel retaining wall is smaller than that of the light emitting layer on the pixel retaining wall, thereby ensuring that each film layer can not generate a non-wetting (De-wetting) phenomenon in the vacuum drying process, improving the material utilization rate to the maximum extent, improving the effective aperture opening rate of the OLED device, improving the performance of the OLED device and further improving the display effect of the display substrate.

In some embodiments, the first solvent comprises: at least one of cyclohexylbenzene, carbonate, an alkyl aromatic hydrocarbon and an aromatic hydrocarbon; the second solvent includes: at least one of aromatic ester, 4-methylanisole and toluene; the third solvent includes: 1, 3-dimethyl-2-imidazolidinone, diethylene glycol, 2- (2-methoxyethoxy) ethanol.

It should be noted that the surface energy of the first solvent may be less than 30mN/m, and the specific material may be at least one of cyclohexylbenzene, carbonate, an alkyl aromatic hydrocarbon, and an aromatic hydrocarbon. The surface energy of the second solvent may be more than 30mN/m and less than 37mN/m, and the specific material may be at least one of aromatic ester, 4-methylanisole, and toluene. The surface energy of the third solvent may be more than 37mN/m and less than 42mN/m, and specifically may be at least one of 1, 3-dimethyl-2-imidazolidinone, diethylene glycol, and 2- (2-methoxyethoxy) ethanol. It is understood that the solvent forming each film layer may be other materials as long as the surface of the solvent material can meet the corresponding requirements, and is not listed here.

It will be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention, and the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and scope of the invention, and such modifications and improvements are also considered to be within the scope of the invention.

Claims

1. A display substrate, comprising: the display device comprises a substrate and a pixel defining layer positioned on the substrate; the pixel defining layer includes: the pixel structure comprises a plurality of pixel retaining walls and accommodating parts defined by the pixel retaining walls; the display substrate further includes: a plurality of organic functional layers formed in the receiving portion; the organic functional layer includes: a hole injection layer, a hole transport layer and a light emitting layer;

the climbing height of the light-emitting layer on the side surface of the pixel retaining wall is at least equal to the climbing height of the hole transport layer on the side surface of the pixel retaining wall along the direction deviating from the substrate, and the climbing height of the hole transport layer on the side surface of the pixel retaining wall is at least equal to the climbing height of the hole injection layer on the side surface of the pixel retaining wall;

the hole injection layer is formed by dropping a first mixed solution formed by mixing a first conductive ink and a first solvent into the accommodating part and performing vacuum drying;

the hole transport layer is formed by dripping a second mixed solution formed by mixing second conductive ink and a second solvent onto the hole injection layer and performing vacuum drying;

the luminescent layer is formed by dripping a third mixed solution formed by mixing a third conductive ink and a third solvent onto the hole transport layer and drying in vacuum.

2. The display substrate according to claim 1, wherein a ratio of a climbing height of the light emitting layer at the side of the pixel retaining wall to a climbing height of the hole transport layer at the side of the pixel retaining wall is 1 to 1.2;

the ratio of the climbing height of the side face of the pixel retaining wall of the hole transport layer to the climbing height of the side face of the pixel retaining wall of the hole injection layer is 1-1.2.

3. The display substrate of claim 2, wherein a ratio of a height of the pixel retaining wall to a climbing height of the hole injection layer on the side of the pixel retaining wall is greater than or equal to 12.5.

4. The display substrate according to claim 3, wherein the height of the pixel retaining wall is 1.0 to 1.5 μm.

5. The display substrate of claim 2, further comprising: a reflective electrode corresponding to the housing portion;

6. The display substrate of claim 1, further comprising: a lyophobic functional layer;

7. A display device comprising the display substrate according to any one of claims 1 to 6.

8. A method for preparing a display substrate is characterized by comprising the following steps:

dripping a third mixed solution formed by mixing a third conductive ink and a third solvent onto the hole transport layer, and forming a light-emitting layer through vacuum drying;

along deviating from in the base direction, the luminescent layer is in climbing height on the pixel barricade side equals at least hole transport layer is in climbing height on the pixel barricade side, hole transport layer is in climbing height on the pixel barricade side equals at least hole injection layer is in climbing height on the pixel barricade side.

9. The method for manufacturing a display substrate according to claim 8, wherein the first solvent comprises: at least one of cyclohexylbenzene, carbonate, an alkylaromatic hydrocarbon and an aromatic hydrocarbon;