CN118367075A - Display panel and method for manufacturing display panel - Google Patents

Abstract

The present disclosure relates to the field of display technology, and in particular to a display panel and a method for preparing the display panel. The display panel includes: a driving substrate, a protective layer and a pixel unit, wherein the pixel unit is bonded to the driving substrate through the protective layer; the pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, and the first hemispherical structure includes a curved surface area and a plane area, and the plane area faces the light-emitting side of the display panel; in the direction perpendicular to the plane area, the area in the curved surface area whose distance from the plane area is greater than or equal to a distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer is located on the side of the light-emitting layer away from the preset area. The technical solution disclosed in the present disclosure can improve the problem of decreased external quantum efficiency of the pixel unit due to uneven electron-hole density in the light-emitting layer, which is beneficial to improving the display effect of the display panel.

Description

Display panel and method for manufacturing display panel

Technical Field

The present disclosure relates to the field of display technology, and in particular to a display panel and a method for preparing the display panel.

Background technique

Micro light emitting diodes (Micro LED) display chips have the characteristics of small size, high integration and self-luminescence, and have greater advantages in brightness, resolution, contrast, energy consumption, service life, response speed and thermal stability. In recent years, with the development of new application scenarios such as automotive lighting, projection, lighting, and communications, users' demand for high-current density and high-brightness Micro LED display chips has continued to increase.

In the related art, for LED devices, there is a serious problem of external quantum efficiency decline when working at high current density, which affects the display effect of the display panel. This is mainly caused by the following reasons: the electron mobility in LED devices is much greater than the hole mobility, causing a large number of electrons to leak directly through the quantum well epitaxial layer (light-emitting layer) before they can recombine with holes; when high current density is injected, the concentration of carriers such as electrons and holes increases, and the Auger recombination between carriers is enhanced, which reduces the luminous efficiency.

Summary of the invention

In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a display panel and a method for preparing a display panel, which can improve the problem of decreased external quantum efficiency of pixel units due to uneven electron-hole density in the light-emitting layer, and is beneficial to improving the display effect of the display panel.

In a first aspect, the present disclosure provides a display panel, comprising:

A driving substrate, a protective layer and a pixel unit, wherein the pixel unit is bonded to the driving substrate through the protective layer;

The pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a flat surface area, and the flat surface area faces the light-emitting side of the display panel;

In the direction perpendicular to the planar area, an area in the curved area whose distance from the planar area is greater than or equal to a distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer is located on a side of the light-emitting layer away from the preset area.

In some embodiments, the display panel further comprises:

An electron blocking layer, located between the hole transport layer and the light emitting layer;

The electron blocking layer covers a side of the light-emitting layer away from the preset area, and the hole transport layer covers a side of the electron blocking layer away from the light-emitting layer.

In some embodiments, the anode of the pixel unit covers a side of the hole transport layer away from the light-emitting layer;

In some embodiments, a first through hole is provided on the protection layer, and a first conductive structure is filled in the first through hole;

The anode of the pixel unit is electrically connected to the bonding electrode of the driving substrate through the first conductive structure.

In some embodiments, the electron transport layer further includes a second hemispherical structure located above the first hemispherical structure;

The plane area of the second hemispherical structure is opposite to the plane area of the first hemispherical structure.

In some embodiments, the display panel further comprises: interconnected cathodes;

A planar region of the second hemispherical structure and an edge position away from the first hemispherical structure are electrically connected to the interconnected cathode.

In some embodiments, the interconnected cathodes include a common area; a second through hole is provided on the protective layer, and a second conductive structure is filled in the second through hole;

The common area is electrically connected to the bonding electrode of the driving substrate through the second conductive structure.

In a second aspect, the present disclosure provides a method for preparing a display panel, comprising:

Prepare a display panel; the display panel comprises: a driving substrate, a protective layer and a pixel unit, and the pixel unit is bonded to the driving substrate through the protective layer;

The pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a flat surface area, and the flat surface area faces the light-emitting side of the display panel;

In the direction perpendicular to the planar area, an area in the curved area whose distance from the planar area is greater than or equal to a distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer is located on a side of the light-emitting layer away from the preset area.

In some embodiments, the step of preparing a display panel includes:

stacking a buffer layer and an electron transport prefabricated layer in sequence on one side of a substrate, etching a side of the electron transport prefabricated layer away from the substrate, and forming a plurality of the first hemispherical structures on the electron transport prefabricated layer;

Covering the protective layer on the side of the electron transport prefabricated layer where the first hemispherical structure is formed, removing part of the protective layer, and retaining the protective layer on the electron transport prefabricated layer between adjacent first hemispherical structures;

Sequentially forming the light-emitting layer and the hole transport layer on the surface of the first hemispherical structure;

Etching a portion of the protective layer to form a cathode patterned area;

Depositing metal on the cathode patterned area to form an interconnected cathode, and depositing metal on the hole transport layer to form an anode of the pixel unit; wherein the interconnected cathode includes a common area;

The protective layer is entirely covered on the side where the anode is located, and a first through hole penetrating to the anode and a second through hole penetrating to the common area are formed on the protective layer, and metal is filled into the first through hole and the second through hole to form a first conductive structure and a second conductive structure respectively;

Bonding the side of the protective layer where the first conductive structure and the second conductive structure are formed to the driving substrate, and peeling off the substrate and the buffer layer;

The side of the electron transport prefabricated layer away from the driving substrate is etched to form a second hemispherical structure, wherein the second hemispherical structure covers the first hemispherical structure, and the second hemispherical structure and the first hemispherical structure form the electron transport layer.

In some embodiments, preparing the display panel includes:

stacking a buffer layer and an electron transport prefabricated layer in sequence on one side of a substrate, etching a side of the electron transport prefabricated layer away from the substrate, and forming a plurality of the first hemispherical structures on the electron transport prefabricated layer;

Covering the protective layer on the side of the electron transport prefabricated layer where the first hemispherical structure is formed, removing part of the protective layer, and retaining the protective layer on the electron transport prefabricated layer between adjacent first hemispherical structures;

Sequentially forming the light-emitting layer, the electron blocking layer and the hole transport layer on the surface of the first hemispherical structure;

Etching a portion of the protective layer to form a cathode patterned area;

Depositing metal on the cathode patterned area to form an interconnected cathode, and depositing metal on the hole transport layer to form an anode of the pixel unit; wherein the interconnected cathode includes a common area;

The protective layer is entirely covered on the side where the anode is located, and a first through hole penetrating to the anode and a second through hole penetrating to the common area are formed on the protective layer, and metal is filled into the first through hole and the second through hole to form a first conductive structure and a second conductive structure respectively;

Bonding the side of the protective layer where the first conductive structure and the second conductive structure are formed to the driving substrate, and peeling off the substrate and the buffer layer;

The side of the electron transport prefabricated layer away from the driving substrate is etched to form a second hemispherical structure, wherein the second hemispherical structure covers the first hemispherical structure, and the second hemispherical structure and the first hemispherical structure form the electron transport layer.

The display panel provided by the embodiment of the present disclosure includes: a driving substrate, a protective layer and a pixel unit, the pixel unit is bonded to the driving substrate through the protective layer; the pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a plane area, the plane area faces the light-emitting side of the display panel; in the direction perpendicular to the plane area, the area in the curved surface area whose distance from the plane area is greater than or equal to the distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer is located on the side of the light-emitting layer away from the preset area. Therefore, the light-emitting layer is provided in the preset area of the first hemispherical structure, so that the light-emitting layer can be provided as a hemispherical hollow structure. The inner surface of the hemispherical hollow structure, that is, the contact surface with the first hemispherical structure, is the electron injection surface, and the outer surface of the hemispherical hollow structure, that is, the opposite surface of the inner surface, is the hole injection surface. Since the outer surface area of the hemispherical hollow structure is larger than the inner surface area, it is equivalent to increasing the electron injection area of the light-emitting layer and reducing the hole injection area of the light-emitting layer, which is beneficial to injecting holes into the light-emitting layer, thereby improving the problem of uneven electron-hole density in the light-emitting layer due to the electron mobility being much greater than the hole mobility, thereby causing a decrease in the external quantum efficiency of the pixel unit, which is beneficial to improving the display effect of the display panel.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

FIG1 is a top view of a display panel provided by an embodiment of the present disclosure;

FIG2 is a schematic diagram of a film layer structure of a display panel provided in an embodiment of the present disclosure;

FIG3 is a schematic diagram of a film layer structure of another display panel provided in an embodiment of the present disclosure;

FIG4 is a schematic diagram of a specific process of a method for manufacturing a display panel provided in an embodiment of the present disclosure;

FIG5 is a schematic diagram of a specific process of a method for manufacturing a display panel provided by an embodiment of the present disclosure;

FIG6 is a top view of a structure corresponding to S504 provided in an embodiment of the present disclosure;

FIG7 is a top view of a structure corresponding to S505 provided in an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a specific process of another method for preparing a display panel provided in an embodiment of the present disclosure.

Detailed ways

In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

The display panel provided by the embodiment of the present disclosure can realize setting the light-emitting layer as a hemispherical hollow structure by setting a coated light-emitting layer in a preset area of the first hemispherical structure. The inner surface of the hemispherical hollow structure, that is, the contact surface with the first hemispherical structure, is the electron injection surface, and the outer surface of the hemispherical hollow structure, that is, the opposite surface of the inner surface, is the hole injection surface. Since the outer surface area of the hemispherical hollow structure is larger than the inner surface area, it is equivalent to increasing the electron injection area of the light-emitting layer and reducing the hole injection area of the light-emitting layer, which is conducive to injecting holes into the light-emitting layer, thereby improving the problem of uneven electron-hole density in the light-emitting layer due to the electron mobility being much larger than the hole mobility, thereby causing the external quantum efficiency of the pixel unit to decrease, which is conducive to improving the display effect of the display panel.

The display panel and the method for manufacturing the display panel provided in the embodiments of the present disclosure are exemplarily described below with reference to the accompanying drawings.

FIG1 is a top view of a display panel provided by an embodiment of the present disclosure, and FIG2 is a schematic diagram of a film structure of a display panel provided by an embodiment of the present disclosure. FIG2 is a cross-sectional view obtained along AA' in FIG1. As shown in FIG1 and FIG2, the display panel includes: a driving substrate 11, a protective layer 21 and a pixel unit 13, wherein the pixel unit 13 is bonded to the driving substrate 11 through the protective layer 21; the pixel unit 13 includes an electron transport layer 14, a light-emitting layer 15 and a hole transport layer 16; the electron transport layer 14 includes a first hemispherical structure 141, and the first hemispherical structure 141 includes a curved surface area and a plane area, and the plane area faces the light-emitting side of the display panel; in a direction perpendicular to the plane area, the area in the curved surface area whose distance from the plane area is greater than or equal to the distance threshold is a preset area; the light-emitting layer 15 covers the preset area, and the hole transport layer 16 is located on the side of the light-emitting layer 15 away from the preset area.

The electron transport layer 14 includes a first hemispherical structure 141, and the first hemispherical structure 141 includes a curved surface area and a flat surface area, the curved surface area faces the drive substrate 11, and the flat surface area faces the light-emitting side of the display panel. For ease of understanding, the flat surface area is shown by a gray line 01, and the surface of the first hemispherical structure 141 is a curved surface area except for the flat surface area.

In the direction YY' perpendicular to the plane area, the preset area is an area in the curved area where the distance from the plane area is greater than or equal to the distance threshold. For ease of understanding, the preset area is shown in a gray dotted frame 02.

Specifically, the light-emitting layer 15 is provided in a preset area of the first hemispherical structure 141, so that the light-emitting layer 15 can be provided as a hemispherical hollow structure. The inner surface of the light-emitting layer 15, i.e., the contact surface with the first hemispherical structure 141, is the electron injection surface, and the outer surface of the light-emitting layer 15, i.e., the surface opposite to the inner surface, is the hole injection surface. Since the outer surface area of the light-emitting layer 15 of the hemispherical hollow structure is larger than the inner surface area, it is equivalent to increasing the electron injection area of the light-emitting layer 15 and reducing the hole injection area of the light-emitting layer 15.

Exemplarily, as shown in FIG2 , the light-emitting layer 15 is set to a hemispherical hollow structure, which can increase the contact area between the light-emitting layer 15 and the hole transport layer 16, and reduce the contact area between the light-emitting layer 15 and the electron transport layer 14. Exemplarily, as shown in FIG3 , the light-emitting layer 15 is set to a hemispherical hollow structure, which can increase the contact area between the light-emitting layer 15 and the electron blocking layer 18. Since the holes in the hole transport layer 16 are transferred to the light-emitting layer 15 through the electron blocking layer 18, it is equivalent to increasing the contact area between the light-emitting layer 15 and the hole transport layer 16, and reducing the contact area between the light-emitting layer 15 and the electron transport layer 14.

This is beneficial for injecting holes into the light-emitting layer 15, thereby improving the problem of uneven electron-hole density in the light-emitting layer 15 due to the electron mobility being much greater than the hole mobility, thereby causing the external quantum efficiency of the pixel unit 13 to decrease, which is beneficial for improving the display effect of the display panel.

The display panel provided by the embodiment of the present disclosure includes: a driving substrate, a protective layer and a pixel unit, the pixel unit is bonded to the driving substrate through the protective layer; the pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a plane area, the plane area faces the light-emitting side of the display panel; in the direction perpendicular to the plane area, the area in the curved surface area whose distance from the plane area is greater than or equal to the distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer covers the side of the light-emitting layer away from the preset area. Thus, the light-emitting layer is provided in the preset area of the first hemispherical structure, so that the light-emitting layer can be provided as a hemispherical hollow structure. The inner surface of the hemispherical hollow structure, that is, the contact surface with the first hemispherical structure, is the electron injection surface, and the outer surface of the hemispherical hollow structure, that is, the opposite surface of the inner surface, is the hole injection surface. Since the outer surface area of the hemispherical hollow structure is larger than the inner surface area, it is equivalent to increasing the electron injection area of the light-emitting layer and reducing the hole injection area of the light-emitting layer, which is beneficial to injecting holes into the light-emitting layer, thereby improving the problem of uneven electron-hole density in the light-emitting layer due to the electron mobility being much greater than the hole mobility, thereby causing a decrease in the external quantum efficiency of the pixel unit, which is beneficial to improving the display effect of the display panel.

Continuing with FIG. 2 , the light-emitting layer 15 is configured as a hemispherical hollow structure. Compared with the prior art in which the light-emitting layer is configured as a long strip, the present disclosure is beneficial for making the distribution of carriers such as electrons and holes in the light-emitting layer 15 more uniform, thereby facilitating improving the situation in which Auger recombination of carriers in the light-emitting layer 15 occurs.

In some embodiments, FIG3 is a schematic diagram of a film structure of another display panel provided in an embodiment of the present disclosure. As shown in FIG3, the display panel further includes: an electron blocking layer 18, located between the hole transport layer 16 and the light-emitting layer 15; the electron blocking layer 18 covers the side of the light-emitting layer 15 away from the preset area, and the hole transport layer 16 covers the side of the electron blocking layer 18 away from the light-emitting layer 15.

Specifically, by providing the electron blocking layer 18 between the hole transport layer 16 and the light emitting layer 15 , it is possible to prevent the electrons injected into the light emitting layer 15 from directly passing through the light emitting layer 15 and leaking.

In some embodiments, referring to FIG. 2 or FIG. 3 , the anode 19 of the pixel unit 13 covers a side of the hole transport layer 16 away from the light emitting layer 15 .

Specifically, by setting the anode 19 of the pixel unit 13 to cover the side of the hole transport layer 16 away from the light-emitting layer 15, the contact area between the anode 19 and the hole transport layer 16 can be increased, which is conducive to achieving rapid heat conduction and large current injection of the display panel. In addition, increasing the contact area between the anode 19 and the hole transport layer 16 is conducive to increasing the injection density of holes into the light-emitting layer 15, which can improve the problem of uneven density of electrons and holes injected into the light-emitting layer 15.

Continuing with reference to FIG. 2 or FIG. 3 , by setting the anode 19 of the pixel unit to cover the side of the hole transport layer 16 away from the light-emitting layer, it is possible to set the anode 19 to a hemispherical hollow structure. The anode 19 with the hemispherical hollow structure can collimate and reflect light, thereby improving the external quantum efficiency of the pixel unit 13 and helping to improve the display effect of the display panel.

Exemplarily, as shown in FIG. 2 , when the light emitted by the light-emitting layer 15 is incident on the anode 19 , it may be reflected on the anode 19 to the light-emitting side, which is beneficial to improving the light emission effect.

In some embodiments, referring to FIG. 2 or FIG. 3 , a first through hole 221 is provided on the protective layer 21, and a first conductive structure 231 is filled in the first through hole 221; the anode 19 of the pixel unit 13 is electrically connected to a bonding electrode (not shown in the figure) of the driving substrate 11 through the first conductive structure 231. Thus, the driving substrate 11 can output a driving signal to the pixel unit 13.

In some embodiments, referring to FIG. 2 or FIG. 3 , the electron transport layer 14 further includes a second hemispherical structure 142 located above the first hemispherical structure 141 ; a plane area of the second hemispherical structure 142 is opposite to a plane area of the first hemispherical structure 141 .

Specifically, when the light emitted by the light emitting layer 15 is emitted through the surface of the second hemispherical structure 142 , the incident angle of the light emitting surface can be smaller than the critical angle of full emission, which is beneficial to improving the light extraction rate and the viewing angle of the display panel.

2 or 3 , setting the projection of the anode 19 on the driving substrate 11 to be within the projection of the second hemispherical structure 142 on the driving substrate 11 can further improve the viewing angle of the display panel.

1 to 3, the display panel further includes: an interconnected cathode 17; and an edge position of the planar region of the second hemispherical structure 142 is electrically connected to the interconnected cathode 17. Specifically, the edge position of the planar region of the second hemispherical structure 142 is electrically connected to the interconnected cathode 17, which can increase the migration path of electrons in the electron transport layer 14, thereby reducing the injection rate of electrons in the light-emitting layer 15.

Exemplarily, in combination with FIG. 1 to FIG. 3 , the second hemispherical structure 142 is set as a large hemisphere, the first hemispherical structure 141 is set as a small hemisphere, the left side of the large hemisphere is connected to the small hemisphere, and the right edge of the large hemisphere is connected to the interconnected cathode 17. In addition, in the horizontal direction XX', a protective layer 21 is provided between the interconnected cathode 17 and the first hemispherical structure 141, and the electrons cannot directly pass through the protective layer 21 to migrate to the first hemispherical structure 141, but migrate to the first hemispherical structure 141 through the second hemispherical structure 142, thereby increasing the transfer path of the electrons in the electron transport layer 14, thereby improving the problem of electron leakage caused by the excessively fast electron mobility.

In some embodiments, referring to FIGS. 1-3 , the interconnected cathode includes a common region 20 ; a second through hole 222 is provided on the protective layer 21 , and a second conductive structure 232 is filled in the second through hole 222 ;

The common region 20 is electrically connected to the bonding electrode (not shown in the figure) of the driving substrate 11 through the second conductive structure 232 , so that the driving substrate 11 can output a driving signal to the pixel unit 13 .

Based on the above embodiments, the present disclosure provides a method for preparing a display panel. The method for preparing a display panel includes: preparing a display panel.

Specifically, as shown in Figures 1 and 2, the display panel includes: a driving substrate 11, a protective layer 21 and a pixel unit 13, the pixel unit 13 is bonded to the driving substrate 11 through the protective layer 21; the pixel unit 13 includes an electron transport layer 14, a light-emitting layer 15 and a hole transport layer 16; the electron transport layer 14 includes a first hemispherical structure 141, the first hemispherical structure 141 includes a curved surface area and a plane area, and the plane area faces the light-emitting side of the display panel; in a direction perpendicular to the plane area, an area in the curved surface area whose distance from the plane area is greater than or equal to a distance threshold is a preset area, the light-emitting layer 15 covers the preset area, and the hole transport layer 16 is located on the side of the light-emitting layer 15 away from the preset area.

Thus, the light-emitting layer is provided in the preset area of the first hemispherical structure, so that the light-emitting layer can be provided as a hemispherical hollow structure. The inner surface of the hemispherical hollow structure, i.e., the contact surface with the first hemispherical structure, is the electron injection surface, and the outer surface of the hemispherical hollow structure, i.e., the surface opposite to the inner surface, is the hole injection surface. Since the outer surface area of the hemispherical hollow structure is larger than the inner surface area, it is equivalent to increasing the electron injection area of the light-emitting layer and reducing the hole injection area of the light-emitting layer, which is conducive to injecting holes into the light-emitting layer, thereby improving the problem of uneven electron-hole density in the light-emitting layer due to the electron mobility being much larger than the hole mobility, thereby causing the external quantum efficiency of the pixel unit to decrease, and is conducive to improving the display effect of the display panel.

In some embodiments, FIG4 is a schematic diagram of a specific process of a method for preparing a display panel provided by an embodiment of the present disclosure. As shown in FIG4, the method for preparing a display panel specifically includes the following steps:

S401 , stacking a buffer layer and an electron transport prefabricated layer in sequence on one side of a substrate, etching a side of the electron transport prefabricated layer away from the substrate, and forming a plurality of first hemispherical structures on the electron transport prefabricated layer.

Specifically, FIG5 is a schematic diagram of a specific process of a method for manufacturing a display panel provided by an embodiment of the present disclosure. In this step, as shown in S501 of FIG5 , a buffer layer 25 and an electron transport prefabricated layer 26 are sequentially stacked on one side of a substrate 24, a side of the electron transport prefabricated layer 26 away from the substrate 24 is etched, and a plurality of first hemispherical structures 141 are formed on the electron transport prefabricated layer 26.

For example, the first hemispherical structure 141 may be manufactured by combining photolithography and wet etching processes, wherein the diameter of the first hemispherical structure 141 may be, for example, 1 um to 2 um.

S402, covering the side of the electron transport prefabricated layer where the first hemispherical structure is formed with a protective layer, removing part of the protective layer, and retaining the protective layer on the electron transport prefabricated layer between adjacent first hemispherical structures.

In this step, as shown in S502 of FIG5 , a protective layer 21 is deposited on the surface of one side of the electron transport prefabricated layer 26 where a plurality of first hemispherical structures 141 are formed, and the protective layer 21 on the surface of the first hemispherical structures 141 is removed by, for example, a photolithography process, and the protective layer 21 on the electron transport prefabricated layer 26 between adjacent first hemispherical structures 141 is retained. The protective layer 21 may be, for example, silicon oxide, and the thickness of the protective layer 21 may be 100 nm-200 nm.

S403 , forming a light-emitting layer and a hole transport layer in sequence on the surface of the first hemispherical structure.

In this step, as shown in S503 of FIG. 5 , the light emitting layer 15 is epitaxially grown on the surface of the first hemispherical structure 141 , and then the hole transport layer 16 is epitaxially grown on the surface of the light emitting layer 15 .

Since the protective layer 21 is provided on the electron transport prefabricated layer 26 between adjacent first hemispherical structures 141, the light-emitting layer 15 and the hole transport layer 16 can only grow sequentially on the surface of the first hemispherical structure 141, thereby realizing selective growth and directly realizing the segmentation of pixel units. There is no need to use etching process to realize independent pixel units, thus effectively avoiding etching damage.

In addition, the light-emitting layer 15 and the hole transport layer 16 grown by the above selection have lower defects and polarization electric fields, which can reduce defect quenching and quantum confined Stark effect (QCSE) of the injected current, and are beneficial to improving the external quantum efficiency of the pixel unit.

S404, etching a portion of the protective layer to form a cathode patterning area.

For example, Fig. 6 is a top view of a structure corresponding to S504 provided in an embodiment of the present disclosure. In this step, in combination with S504 of Fig. 5 and Fig. 6 , the protective layer 21 is selectively etched to form a cathode patterned region 017 .

S405, depositing metal on the cathode patterning area to form an interconnected cathode, and depositing metal on the hole transport layer to form an anode of the pixel unit; wherein the interconnected cathode includes a common area.

Exemplarily, FIG7 is a top view of a structure corresponding to S505 of an embodiment of the present disclosure. Specifically, in this step, in combination with S505 of FIG5 , FIG6 and FIG7 , metal is deposited on the cathode patterning area 017 to form an interconnected cathode 17, and metal is deposited on the hole transport layer 16 to form an anode 19 of the pixel unit. The interconnected cathode 17 includes a common area 20.

S406, covering the entire surface of the anode side with a protective layer, forming a first through hole penetrating to the anode and a second through hole penetrating to the common area on the protective layer, and filling the first through hole and the second through hole with metal to form a first conductive structure and a second conductive structure respectively.

Specifically, in this step, as shown in S506 of Figure 5, the protective layer 21 is entirely covered on the side where the anode is located to flatten it, and a first through hole 221 penetrating to the anode 19 and a second through hole 222 penetrating to the common area 20 are formed on the protective layer 21; metals such as copper or tungsten are filled into the first through hole 221 and the second through hole 222 to form a first conductive structure 231 and a second conductive structure 232, respectively.

S407 , bonding the side of the protective layer where the first conductive structure and the second conductive structure are formed to the driving substrate, and peeling off the substrate and the buffer layer.

Specifically, in this step, as shown in S507 of FIG. 5 , the protective layer 21 is bonded to the driving substrate 11 , and the substrate 24 and the buffer layer 25 are peeled off.

S408 , etching the side of the electron transport prefabricated layer away from the driving substrate to form a second hemispherical structure, the second hemispherical structure covers the first hemispherical structure, and the second hemispherical structure and the first hemispherical structure form an electron transport layer.

Specifically, in this step, as shown in S508 of FIG. 5 , the electron transport prefabricated layer 26 shown in S507 is etched to form a second hemispherical structure 142 corresponding to the first hemispherical structure 141 , and the first hemispherical structure 141 and the second hemispherical structure 142 form the electron transport layer 14 .

For example, FIG8 is a schematic diagram of a specific process of another method for preparing a display panel provided in an embodiment of the present disclosure.

As shown in FIG. 8 , in S801 , a buffer layer 25 and an electron transport prefabricated layer 26 are sequentially stacked on one side of a substrate 24 , a side of the electron transport prefabricated layer 26 away from the substrate 24 is etched, and a plurality of first hemispherical structures 141 are formed on the electron transport prefabricated layer 26 .

In S802 , the protective layer 21 is covered on one side of the electron transport prefabricated layer 26 where the first hemispherical structure 141 is formed, and a portion of the protective layer 21 is removed, and the protective layer 21 on the electron transport prefabricated layer 26 between adjacent first hemispherical structures 141 is retained.

In S803 , a light emitting layer 15 , an electron blocking layer 18 and a hole transport layer 16 are sequentially formed on the surface of the first hemispherical structure 141 .

In S804 , a portion of the protection layer 21 is etched to form a cathode patterned region 017 .

In S805 , metal is deposited on the cathode patterning region 017 to form an interconnected cathode 17 , and metal is deposited on the hole transport layer 16 to form an anode 19 of the pixel unit; wherein the interconnected cathode 17 includes a common region 20 .

In S806, the protective layer 21 is entirely covered on the side where the anode 19 is located, and a first through hole 221 penetrating to the anode 19 and a second through hole 222 penetrating to the common area 20 are formed on the protective layer 21, and metal is filled into the first through hole 221 and the second through hole 222 to form a first conductive structure 231 and a second conductive structure 232, respectively.

In S807 , the side of the protection layer 21 where the first conductive structure 231 and the second conductive structure 232 are formed is bonded to the driving substrate 11 , and the substrate 24 and the buffer layer 25 are peeled off.

In S807 , the side of the electron transport prefabricated layer 26 away from the driving substrate 11 is etched to form a second hemispherical structure 142 . The second hemispherical structure 142 covers the first hemispherical structure 141 . The second hemispherical structure 142 and the first hemispherical structure 141 form an electron transport layer 14 .

The difference between Figure 5 and Figure 8 is that: in Figure 5 S803, a light-emitting layer and a hole transport layer are formed in sequence on the surface of the first hemispherical structure, and the display panel shown in Figure 2 can be formed corresponding to the steps shown in Figure 5; in Figure 6 S803, a light-emitting layer, an electron blocking layer and a hole transport layer are formed in sequence on the surface of the first hemispherical structure, and the display panel shown in Figure 3 can be formed corresponding to the steps shown in Figure 8.

On the basis of the above embodiments, the present disclosure further provides a display device, including the display panel as described in the above embodiments, and thus has the same or similar beneficial effects, which will not be described in detail herein.

It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A display panel, comprising: A driving substrate, a protective layer and a pixel unit, wherein the pixel unit is bonded to the driving substrate through the protective layer; The pixel unit includes an electron transport layer, a light-emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a flat surface area, and the flat surface area faces the light-emitting side of the display panel; In the direction perpendicular to the plane area, an area in the curved area whose distance from the plane area is greater than or equal to a distance threshold is a preset area; the light-emitting layer covers the preset area, and the hole transport layer is located on a side of the light-emitting layer away from the preset area. 2. The display panel according to claim 1, further comprising: An electron blocking layer, located between the hole transport layer and the light emitting layer; The electron blocking layer covers a side of the light-emitting layer away from the preset area, and the hole transport layer covers a side of the electron blocking layer away from the light-emitting layer. 3 . The display panel according to claim 1 , wherein the anode of the pixel unit covers a side of the hole transport layer away from the light-emitting layer. 4. The display panel according to claim 3, wherein a first through hole is provided on the protection layer, and a first conductive structure is filled in the first through hole; The anode of the pixel unit is electrically connected to the bonding electrode of the driving substrate through the first conductive structure. 5. The display panel according to claim 1, wherein the electron transport layer further comprises a second hemispherical structure located above the first hemispherical structure; The plane area of the second hemispherical structure is opposite to the plane area of the first hemispherical structure. 6. The display panel according to claim 5, further comprising: interconnected cathodes; A planar region of the second hemispherical structure and an edge position away from the first hemispherical structure are electrically connected to the interconnected cathode. 7. The display panel according to claim 6, characterized in that the interconnected cathodes include a common area; a second through hole is provided on the protective layer, and a second conductive structure is filled in the second through hole; The common area is electrically connected to the bonding electrode of the driving substrate through the second conductive structure. 8. A method for preparing a display panel, comprising: Prepare a display panel; the display panel comprises: a driving substrate, a protective layer and a pixel unit, and the pixel unit is bonded to the driving substrate through the protective layer; The pixel unit includes an electron transport layer, a light emitting layer and a hole transport layer; the electron transport layer includes a first hemispherical structure, the first hemispherical structure includes a curved surface area and a flat surface area, and the flat surface area faces the light emitting side of the display panel; In the direction perpendicular to the planar area, an area in the curved area whose distance from the planar area is greater than or equal to a distance threshold is a preset area, the light-emitting layer covers the preset area, and the hole transport layer is located on a side of the light-emitting layer away from the preset area. 9. The method for preparing a display panel according to claim 8, characterized in that the preparing the display panel comprises: stacking a buffer layer and an electron transport prefabricated layer in sequence on one side of the substrate, etching a side of the electron transport prefabricated layer away from the substrate, and forming a plurality of the first hemispherical structures on the electron transport prefabricated layer; Covering the protective layer on the side of the electron transport prefabricated layer where the first hemispherical structure is formed, removing part of the protective layer, and retaining the protective layer on the electron transport prefabricated layer between adjacent first hemispherical structures; Sequentially forming the light-emitting layer and the hole transport layer on the surface of the first hemispherical structure; Etching a portion of the protective layer to form a cathode patterned area; Depositing metal on the cathode patterned area to form an interconnected cathode, and depositing metal on the hole transport layer to form an anode of the pixel unit; wherein the interconnected cathode includes a common area; The protective layer is entirely covered on the side where the anode is located, and a first through hole penetrating to the anode and a second through hole penetrating to the common area are formed on the protective layer, and metal is filled into the first through hole and the second through hole to form a first conductive structure and a second conductive structure respectively; Bonding the side of the protective layer where the first conductive structure and the second conductive structure are formed to the driving substrate, and peeling off the substrate and the buffer layer; The side of the electron transport prefabricated layer away from the driving substrate is etched to form a second hemispherical structure, wherein the second hemispherical structure covers the first hemispherical structure, and the second hemispherical structure and the first hemispherical structure form the electron transport layer. 10. The method for preparing a display panel according to claim 8, characterized in that the preparing the display panel comprises: stacking a buffer layer and an electron transport prefabricated layer in sequence on one side of the substrate, etching a side of the electron transport prefabricated layer away from the substrate, and forming a plurality of the first hemispherical structures on the electron transport prefabricated layer; Covering the protective layer on the side of the electron transport prefabricated layer where the first hemispherical structure is formed, removing part of the protective layer, and retaining the protective layer on the electron transport prefabricated layer between adjacent first hemispherical structures; Sequentially forming the light-emitting layer, the electron blocking layer and the hole transport layer on the surface of the first hemispherical structure; Etching a portion of the protective layer to form a cathode patterned area; Depositing metal on the cathode patterned area to form an interconnected cathode, and depositing metal on the hole transport layer to form an anode of the pixel unit; wherein the interconnected cathode includes a common area; The protective layer is entirely covered on the side where the anode is located, and a first through hole penetrating to the anode and a second through hole penetrating to the common area are formed on the protective layer, and metal is filled into the first through hole and the second through hole to form a first conductive structure and a second conductive structure respectively; Bonding the side of the protective layer where the first conductive structure and the second conductive structure are formed to the driving substrate, and peeling off the substrate and the buffer layer; The side of the electron transport prefabricated layer away from the driving substrate is etched to form a second hemispherical structure, wherein the second hemispherical structure covers the first hemispherical structure, and the second hemispherical structure and the first hemispherical structure form the electron transport layer.