CN117529166A

CN117529166A - Display panel, manufacturing method thereof and display device

Info

Publication number: CN117529166A
Application number: CN202311365056.2A
Authority: CN
Inventors: 高栋雨; 金奕辰; 宋裕斌; 安成国
Original assignee: BOE Technology Group Co Ltd; Chongqing BOE Display Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chongqing BOE Display Technology Co Ltd
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2024-02-06

Abstract

The embodiment of the disclosure provides a display panel, a manufacturing method thereof and a display device, and belongs to the technical field of display. The display panel comprises a driving backboard and a light-emitting functional layer positioned on the driving backboard, wherein the light-emitting functional layer comprises a pixel definition layer and a plurality of light-emitting units. The pixel defining layer is provided with a plurality of openings distributed in an array, and the pixel defining layer comprises a conductive part. The plurality of light-emitting units are respectively located in one opening, each light-emitting unit comprises a first electrode, a light-emitting layer and a second electrode which are sequentially stacked along the direction away from the driving backboard, the second electrode of each light-emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the plurality of light-emitting units are insulated from the conductive part. The embodiment of the disclosure can improve the problem of uneven display in the central area and the peripheral area of the display panel.

Description

Display panel, manufacturing method thereof and display device

Technical Field

The embodiment of the disclosure relates to the technical field of display, in particular to a display panel, a manufacturing method thereof and a display device.

Background

The display device has wide application scenes in life, such as electronic equipment of mobile phones, tablet computers and the like. The display panel is an important component of the display device.

In the related art, the display panel comprises a driving backboard and a light-emitting functional layer on the driving backboard, the light-emitting functional layer comprises a pixel definition layer and a plurality of light-emitting units, a plurality of openings distributed in an array are formed in the pixel definition layer, the light-emitting units are respectively located in one opening, the light-emitting units comprise a first electrode, a light-emitting layer and a second electrode which are sequentially stacked along a direction far away from the driving backboard, and the second electrodes are connected into a whole layer structure to form a second electrode layer.

However, in the process of transferring an electric signal from the edge of the second electrode layer to the center of the second electrode layer, as the transfer distance increases, the resistance in the transfer process increases, which causes a voltage drop of the electric signal, and thus the electric signal on the second electrode located in the center area of the display panel and the electric signal on the second electrode located in the peripheral area of the display panel differ in voltage, resulting in a problem of uneven display between the center area and the peripheral area of the display panel, which is more apparent on a larger-sized display panel.

Disclosure of Invention

The embodiment of the disclosure provides a display panel, a manufacturing method thereof and a display device, which can improve the problem of uneven display in the central area and the peripheral area of the display panel. The technical scheme is as follows:

in one aspect, a display panel is provided, the display panel including a driving back plate, and a light emitting functional layer on the driving back plate, the light emitting functional layer including a pixel defining layer and a plurality of light emitting units; the pixel definition layer is provided with a plurality of openings distributed in an array, and comprises a conductive part; the light emitting units are respectively located in one opening, each light emitting unit comprises a first electrode, a light emitting layer and a second electrode which are sequentially stacked along the direction away from the driving backboard, the second electrode of each light emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the light emitting units are insulated from the conductive part.

Optionally, the pixel defining layer includes only the conductive portion, the light emitting functional layer further includes a plurality of insulating structures, the plurality of insulating structures and the plurality of light emitting units are in one-to-one correspondence, and the insulating structures and the corresponding light emitting units are located in the same opening and surround the first electrodes of the corresponding light emitting units.

Optionally, the insulating structure further surrounds the light emitting layer of the corresponding light emitting unit, and the thickness of the insulating structure is greater than the sum of the thicknesses of the first electrode and the light emitting layer.

Optionally, the radial dimension of the insulating structure is 1 μm to 10 μm.

Optionally, the pixel defining layer further includes an insulating portion, and the insulating portion is located at a side of the conductive portion near the driving back plate.

Optionally, the thickness of the insulating part is greater than the sum of the thicknesses of the first electrode and the light emitting layer.

Optionally, the display panel further includes a protective layer, where the protective layer is located on a side of the pixel defining layer away from the driving back plate.

Optionally, the thickness of the protective layer is 0.5-1 μm.

Optionally, the protection layer includes a first strip structure located between two adjacent light emitting units, the first strip structure has a first side wall and a second side wall opposite to each other, and a plane where the first side wall and a plane where the second side wall are located intersect at a side of the protection layer away from the driving backboard.

Optionally, the display panel further includes a conductive structure, where the conductive structure is in the same layer as the second electrode and is connected to the second electrode, and the conductive structure is located on a side of the protective layer away from the driving back plate.

Optionally, the thickness of the conductive part is 0.5 μm to 1 μm.

Optionally, the conductive portion is made of a metal material.

Optionally, the first electrode includes a first sub-layer, a second sub-layer, and a third sub-layer sequentially stacked on the driving back plate; the first sub-layer and the third sub-layer are made of transparent conductive materials, and the second sub-layer is made of metal materials.

In another aspect, a method for manufacturing a display panel is provided, the method including: providing a driving backboard; manufacturing a light-emitting functional layer on the driving backboard, wherein the light-emitting functional layer comprises a pixel definition layer and a plurality of light-emitting units; the pixel definition layer comprises a conductive part, a plurality of light emitting units are respectively positioned in one opening, each light emitting unit comprises a first electrode, a light emitting layer and a second electrode which are sequentially stacked along the direction far away from the driving backboard, the second electrode of each light emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the light emitting units are insulated from the conductive part.

In yet another aspect, a display device is provided that includes a power supply circuit and any of the foregoing display panels, the power supply circuit supplying power to the display panels.

The beneficial effects that this disclosure provided technical scheme brought include at least: by arranging the conductive part which is connected with the second electrode and is conductive in the pixel definition layer, the cross section area of the current on the second electrode on the transmission path is increased, the resistance is reduced, the voltage drop is reduced, and the problem of uneven display in the central area and the peripheral area of the display panel is solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 is a schematic cross-sectional structure of a display panel according to an embodiment of the present disclosure;

FIG. 2 is a schematic view showing a projection relationship between an insulating structure and a second electrode of a light emitting unit according to an embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional view of another display panel according to an embodiment of the present disclosure;

fig. 4 is a schematic plan view of another display panel according to an embodiment of the present disclosure;

FIG. 5 is a schematic cross-sectional view of another display panel according to an embodiment of the present disclosure;

FIG. 6 is a schematic cross-sectional view of another display panel according to an embodiment of the present disclosure;

FIG. 7 is a schematic cross-sectional view of a first electrode according to an embodiment of the present disclosure;

fig. 8 is a schematic cross-sectional structure of a display panel according to an embodiment of the present disclosure;

fig. 9 is a schematic cross-sectional structure of a light-emitting layer provided in an embodiment of the present disclosure;

fig. 10 is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of the disclosure;

fig. 11 is a schematic flow chart of a first part of a manufacturing method of a display panel according to an embodiment of the disclosure;

fig. 12 is a schematic flow chart of a second part of a manufacturing method of a display panel according to an embodiment of the disclosure.

Legend description:

1. driving backboard

11. Substrate 12, gate layer 13, source/drain layer 14, active layer 15, gate insulating layer 16, planarization layer 17, passivation layer 18, and interlayer dielectric layer

2. First electrode

201. First sub-layer 202, second sub-layer 203, third sub-layer

31. Pixel definition layer

31a, a conductive portion 31b, an insulating portion 31c, and an opening

32. Second electrode

33. Conductive structure

4. Light-emitting layer

41. First light-emitting layer 42, second light-emitting layer 43, third light-emitting layer 401, hole injection layer 402, hole transport layer 403, electron blocking layer 404, light-emitting material layer 405, hole blocking layer 406, electron transport layer 407, electron injection layer

5. Protective layer 50, first stripe structure

6. Insulating structure 7, first light extraction layer 8, second light extraction layer 9, and encapsulation layer

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present disclosure more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The terminology used in the description of the embodiments of the disclosure is for the purpose of describing the embodiments of the disclosure only and is not intended to be limiting of the disclosure. Unless defined otherwise, technical or scientific terms used in the embodiments of the present disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure belongs. The terms "first," "second," "third," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are present in front of "comprising" or "comprising" are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. References to directional terms in this disclosure, such as "top", "bottom", "upper", "lower", "left" or "right", etc., are merely with reference to the orientation of the drawings, and thus are used in order to better and more clearly illustrate and understand the disclosed embodiments, rather than to indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the disclosed embodiments.

Fig. 1 is a schematic cross-sectional structure of a display panel according to an embodiment of the present disclosure. As shown in fig. 1, the display panel includes a driving back plate 1 and a light emitting functional layer on the driving back plate 1, the light emitting functional layer including a pixel defining layer 31 and a plurality of light emitting cells a. The pixel defining layer 31 has a plurality of openings 31c distributed in an array, and the pixel defining layer 31 includes a conductive portion 31a. The plurality of light emitting units a are respectively located in one opening 31c, i.e., one light emitting unit a is provided in each opening 31 c. The light emitting units a include a first electrode 2, a light emitting layer 4, and a second electrode 32 sequentially stacked in a direction away from the driving backplate 1, the second electrode 32 of each light emitting unit a is connected to a conductive portion 31a, and the thickness of the conductive portion 31a is greater than that of the second electrode 32, and the first electrodes 2 of the plurality of light emitting units a are insulated from the conductive portion 31a.

In the embodiment of the disclosure, the second electrode 32 is connected to the thicker conductive portion 31a, and the electrical signal on the second electrode 32 passes through the plurality of thinner second electrodes 32 and also passes through the thicker conductive portion 31a in the process of being transferred from the second electrode 32 located in the peripheral area of the display panel to the second electrode 32 located in the central area of the display panel, the thicker conductive portion 31a increases the cross-sectional area of the conductor on the current transmission path, so that the resistance on the current transmission path can be reduced, the voltage drop can be reduced, and the problem of uneven display in the central area and the peripheral area of the display panel can be improved. Meanwhile, the thickness of the second electrode 32 is not increased in order to reduce the voltage drop, thereby affecting the light extraction.

In a possible embodiment, as shown in fig. 1, the pixel defining layer 31 includes only the conductive portion 31a, and the light emitting functional layer further includes a plurality of insulating structures 6, where the plurality of insulating structures 6 are in one-to-one correspondence with the plurality of light emitting units a, and the insulating structures 6 are located in the same opening as the corresponding light emitting units a and surround the first electrodes 2 of the corresponding light emitting units. The insulating structure 6 can insulate the first electrode 2 from the conductive portion 31a, and prevent the electrical signals on the first electrode 2 and the second electrode 32 from interfering with each other through the conductive portion 31a.

Illustratively, as shown in fig. 1, the insulating structure 6 surrounds the light emitting layer 4, and the thickness of the insulating structure 6 is greater than or equal to the sum of the thicknesses of the first electrode 2 and the light emitting layer 4. The insulating structure 6 isolates the light emitting layer 4 and the conductive portion 31a, and light leakage caused by direct contact between the light emitting layer 4 and the conductive portion 31a is avoided.

Alternatively, the thickness of the insulating structure 6 is 100nm to 500nm greater than the sum of the thicknesses of the first electrode 2 and the light emitting layer 4. The insulating structure in this thickness range relation can exert a sufficient insulating effect between the first electrode 2 and the light-emitting layer 4 and the conductive portion 31a, and does not affect the connection of the second electrode 32 and the conductive portion 31a due to excessive thickness.

Illustratively, in the embodiment shown in fig. 1, the conductive portion 31a is further connected to a trace layer in the driving backplate 1, the trace layer is located between the source-drain layer and the plurality of first electrodes 2, and the trace layer includes a plurality of traces thereon, and the plurality of traces are connected to traces (e.g., VSS traces) located at the periphery of the display panel for transmitting the electrical signals of the second electrodes 32. The film structure of the driving back plate 1 between the wiring layer and the conductive portion 31a has a plurality of openings, and the conductive portion 31a is connected to the wiring layer through the openings. The electrical signal on the second electrode 32 may be transferred to the second electrode 32 located in the central area of the display panel through a plurality of traces in the trace layer. Because the wiring is made of metal materials (such as titanium aluminum titanium laminated metal), the resistance is small, the resistance on a current transmission path can be reduced, and the voltage drop is reduced, so that the problem of uneven display in the central area and the peripheral area of the display panel is solved.

Optionally, a plurality of open holes in the film structure between the wiring layer and the conductive portion 31a in the driving backplate 1 are distributed in an array, so as to divide the display area into a plurality of display sub-areas, so that the display effect of each display sub-area is as uniform as possible.

Alternatively, the plurality of traces in the trace layer may be arranged in parallel, and an extending direction of the plurality of traces may be the same as an extending direction of the data line or the gate line.

In the embodiment of the disclosure, the connection manner between the plurality of second electrodes 32 and the wires located at the periphery of the display panel and used for transmitting the electrical signals of the second electrodes 32 is not limited, and the two wires can be electrically connected through other film layers, for example, the wires on the source-drain electrode layer are connected, and the extending directions of the wires are the same as the extending directions of the data wires.

Fig. 2 is a schematic diagram of a projection relationship between an insulating structure and a second electrode of a light emitting unit according to an embodiment of the present disclosure. Illustratively, as shown in fig. 2, the sum of the front projection of the insulating structure 6 on the driving backplate 1 and the front projection of the first electrode 2 on the driving backplate 1 coincides with the front projection of the second electrode 32 on the driving backplate 1, i.e. the second electrode 32 covers only the first electrode 2 and the insulating structure 6. In the horizontal direction, the projected relationship of the insulating structure 6, the first electrode 2, and the second electrode 32 may be such that the insulating structure 6 is located between the first electrode 2 or the light emitting layer 4 and the conductive portion 31a, and the second electrode 32 is connected to the conductive portion 31a.

In order to clearly show the relationship between the first electrode 2 and the insulating structure 6, the second electrode 32 and the light-emitting layer 4 are not shown in fig. 2. Optionally, the position of the light emitting layer 4 coincides with the position of the first electrode 2, i.e. the front projection of the light emitting layer 4 on the driving backplate 1 coincides with the front projection of the first electrode 2 on the driving backplate. Alternatively, the first electrode 2 is an anode, the first electrode layer where the plurality of first electrodes 2 are located is an anode layer, the second electrode 32 is a cathode, and the plurality of second electrodes 32 are connected to the conductive portion 31a to form a cathode layer. Wherein the pixel defining layer 31 not only functions to separate a plurality of light emitting cells but also multiplexes as part of the cathode layer.

Optionally, the display panel includes a plurality of light emitting units distributed in an array along the first direction x and the second direction y. The plurality of light emitting units a include a first light emitting unit A1, a second light emitting unit A2, and a third light emitting unit A3. The first, second and third light emitting units A1, A2 and A3 emit light of different colors, respectively, for example, the colors of the light emitted from the first, second and third light emitting units A1, A2 and A3 are red, green and blue, respectively. The light emitting areas corresponding to the sub-pixels of the first, second and third light emitting units A1, A2 and A3 are the first, second and third light emitting areas, respectively.

Illustratively, as shown in FIG. 2, the pixel defining layer 31 has a plurality of openings thereon, and the distance a between two adjacent openings is 2 μm to 20 μm. The lower limit of the dimension depends on the process precision of the existing lithography equipment, and the upper limit depends on the specific product design, and the larger the width is, the smaller the opening ratio of the corresponding product is.

Illustratively, the conductive portion 31a is made of a metallic material. The conductive portion 31a made of the opaque metal material can play a role in preventing the colors emitted from the adjacent light emitting layers 4 from being mutually crosstalked, and since the metal material can reflect light emitted from the light emitting layers 4 to the side wall of the conductive portion 31a, the light can be reflected to the light emitting surface of the display panel, which is beneficial to improving the light emitting.

The second electrode 32 is illustratively made of a transparent conductive material or a translucent conductive material. The second electrode 32 made of a transparent conductive material or a semitransparent conductive material has little influence on light emission. Alternatively, the second electrode 32 is made of a transparent conductive material such as ITO (Indium tin oxide), IZO (Indium Zinc Oxide ), or a translucent material such as magnesium silver alloy.

The thickness of the second electrode 32 is, for example, 8nm to 30nm. The second electrode 32 located in this size range is thin and has little influence on light emission. Alternatively, the thickness of the second electrode 32 is about 15nm.

The thickness of the conductive portion 31a is, for example, 0.5 μm to 1 μm. The pixel defining layer including the conductive portion 31a of this size range is thick, can sufficiently separate the light emitting layers 4 from each other, and allows the relatively thin second electrode 32 to be stably connected to the conductive portion 31a.

The insulating structure 6 is made of polyimide, silicon nitride or silicon nitride, for example. These materials not only have insulating properties, but also play a role in protecting the light-emitting layer 4 and preventing the light-emitting layer 4 from being excessively etched abnormally during the manufacturing process of the display panel.

Illustratively, as shown in FIG. 2, the insulating structure 6 has a radial dimension b of 1 μm to 10 μm. The insulating structure 61 located within this size range is not inferior in insulating performance due to undersize in the radial direction; also, since the insulating structure 61 made of polyimide, silicon nitride or silicon oxide is transparent, the insulating structure 6 having an excessively large radial dimension may cause the area of the light emitting layer 4 to be small, and affect the light emission.

Illustratively, as shown in fig. 1, the display panel further includes a protective layer 5, and the protective layer 5 is located on a side of the pixel defining layer 31 away from the driving back plate 1. The protective layer 5 plays a role in protecting the pixel defining layer 31 from being etched away during the fabrication of the display panel. Optionally, the protective layer 5 is made of silicon nitride or silicon oxide, and the transparent silicon nitride or silicon oxide has less influence on light emission.

Fig. 3 is a schematic cross-sectional structure of another display panel according to an embodiment of the present disclosure. As shown in FIG. 3, the thickness h of the protective layer 5 is 0.5 to 1. Mu.m. If the protective layer 5 is too thin, the protective effect of the conductive portion 31a is poor.

Fig. 4 is a schematic plan view of another display panel according to an embodiment of the disclosure. As shown in fig. 3 and 4, the protective layer 5 includes a first stripe structure 50 located between two adjacent second electrodes 32, the first stripe structure 50 having opposite first and second sidewalls 50a and 50b. The plane of the first sidewall 50a and the plane of the second sidewall 50b intersect at a side of the protection layer 5 away from the driving back plate 1 to form an included angle θ.

Optionally, the included angle θ ranges from 100 ° to 140 °.

Alternatively, the surface of the first sidewall 50a or the second sidewall 50b may be an arc surface. For example, it may be a cambered surface recessed in a direction approaching the drive backplate.

Illustratively, referring again to fig. 3, the display panel further comprises a conductive structure 33, the conductive structure 33 being co-layered and connected with the plurality of second electrodes 32, the conductive structure 33 being located on a side of the protective layer 5 remote from the driving backplate 1. The conductive structure 33 can further increase the cross-sectional area of the conductor of the current in the second electrode 32 on the transmission path, thereby reducing the resistance, reducing the voltage drop, and further improving the problem of uneven display in the central area and the peripheral area of the display panel.

In the presently disclosed embodiments, the term "co-layer" refers to a relationship between layers that are formed simultaneously in the same step, e.g., when the conductive structure 33 and the second electrode 32 are formed for one or more steps that perform the same patterning process in the same layer of material, they are in the same layer. The term "co-layer" does not always mean that the layers are identical in thickness or in cross-sectional view.

For the protective layer 5 and the conductive structure 33, it is disadvantageous that the conductive structure 33 is connected to the second electrode 32 if the protective layer 5 is too thick. The first sidewall 50a and the second sidewall 50b of the first stripe structure 50 may have slopes, for example, when the included angle θ is 100 ° to 140 °, so that the conductive structure 33 is connected to the second electrode 32.

Fig. 5 is a schematic cross-sectional structure of another display panel according to an embodiment of the present disclosure. In another possible embodiment, as shown in fig. 5, the pixel defining layer further includes an insulating portion 31b, and the insulating portion 31b is located on a side of the conductive portion 31a near the driving backplate 1. Namely, the pixel defining layer is divided into an upper half portion, which is a conductive portion 31a, and a lower half portion, which is an insulating portion 31b. Since the insulating portion 31b is located on the side of the conductive portion 31a close to the driving backplate 1, the first electrode 2 can be insulated from the conductive portion 31a. In addition, compared with the embodiment shown in fig. 1, since the insulating structure 6 is not provided in the embodiment shown in fig. 5, the embodiment shown in fig. 5 is advantageous in that the light emitting area is increased and the aperture ratio of the display panel is improved.

Alternatively, as shown in fig. 5, the thickness of the insulating portion 31b is larger than the sum of the thicknesses of the first electrode 2 and the light emitting layer 4. Since the thickness of the insulating portion 31b in the pixel defining layer 31 is larger than the sum of the thicknesses of the first electrode and the light emitting layer, an insulating structure may not be required, and connection of the first electrode 2 and the light emitting layer 4 to the conductive portion through the insulating portion 31b may be avoided.

Fig. 6 is a schematic cross-sectional structure of another display panel according to an embodiment of the present disclosure. As shown in fig. 6, the display panel may have both the insulating structure 6 and the insulating portion 31b. The insulating portion 31b and the insulating structure 6 are provided at the same time, so that a more sufficient insulating effect can be achieved between the first electrode 2 and the light-emitting layer 4 and the conductive portion 31a. Alternatively, as shown in fig. 6, the insulating portion 31b may be thinner than the insulating structure 6, and the thickness of the insulating structure 6 may be 100nm to xxnm greater than the sum of the thicknesses of the first electrode 2 and the light emitting layer 4. Alternatively, the insulating portion 31b may be thicker than the insulating structure 6, and the thickness of the insulating portion 31b is 100nm to 300nm greater than the sum of the thicknesses of the first electrode 2 and the light emitting layer 4. The insulating structure 6 or the insulating portion 31b located in the thickness range relation can provide a sufficient insulating effect between the first electrode 2 and the light emitting layer 4 and the conductive portion 31a, and does not affect the connection of the second electrode 32 and the conductive portion 31a due to excessive thickness.

Illustratively, in the embodiment shown in fig. 5 or 6, the conductive portion 31a is connected to a trace layer in the driving backplate 1, the trace layer is located between the source-drain layer and the plurality of first electrodes 2, and the trace layer includes a plurality of traces thereon, and the plurality of traces are connected to traces (e.g., VSS traces) located at the periphery of the display panel for transmitting electrical signals of the second electrodes 32. The driving back plate 1 has a film structure between the wiring layer and the pixel defining layer 31, and a plurality of openings in the insulating portion 31b, and the conductive portion 31a is connected to the source/drain layer through the openings. Because the wiring is made of metal materials (such as titanium aluminum titanium laminated metal), the resistance is small, the resistance on a current transmission path can be reduced, and the voltage drop is reduced, so that the problem of uneven display in the central area and the peripheral area of the display panel is solved. The possible arrangement of the openings, the arrangement of the plurality of wires in the wire layer, and the like are the same as those described above, and will not be repeated here.

Fig. 7 is a schematic cross-sectional structure of a first electrode according to an embodiment of the present disclosure. As shown in fig. 6, the first electrode 2 includes a first sub-layer 201, a second sub-layer 202, and a third sub-layer 203, which are sequentially stacked on a driving back plate. The first sub-layer 201 and the third sub-layer 203 are made of transparent conductive materials, and the second sub-layer 202 is made of metal materials. The second sub-layer 202 made of metal material can reflect the light emitted by the light emitting layer 4 to the light emitting surface of the display panel, so as to facilitate the light emitting, and the first sub-layer 201 and the third sub-layer 203 have the function of protecting the second sub-layer 202, for example, preventing the second sub-layer 202 from being oxidized, and the third sub-layer 203 is transparent so as not to affect the light reflected by the second sub-layer 202. Alternatively, the first sub-layer 201 and the third sub-layer 203 are made of ITO and the second sub-layer 202 is made of silver.

Alternatively, the thickness of the first electrode 2 (i.e. the sum of c, d, e) is 500-1500 nm, the thickness c of the first sub-layer 201 is 10-100 nm, the thickness e of the third sub-layer 203 is 30-200 nm, and the thickness e of the third sub-layer 203 is greater than the thickness c of the first sub-layer 201. For example, the thickness e of the third sub-layer 203 is 60nm to 80nm, and the thickness c of the first sub-layer 201 is 20nm to 40nm. In the manufacturing process of the display panel, a plurality of etching processes are performed on one side of the third sub-layer 203, and the second sub-layer 202 can be better protected by thicker third sub-layer 203.

Illustratively, referring again to fig. 1, the display panel further comprises a first light extraction layer 7 and a second light extraction layer 8. The first light extraction layer 7 is located on the side of the second electrode 32 and the conductive structure 33 remote from the driving back plate 1. The second light extraction layer 8 is located at a side of the first light extraction layer 7 remote from the driving back plate 1, and the refractive index of the first light extraction layer 7 is smaller than that of the second light extraction layer 8. The first light extraction layer 7 and the second light extraction layer 8 with different refractive indexes are matched, so that the optical interference distance can be adjusted, external light reflection is restrained, extinction caused by surface plasma is restrained, light extraction efficiency is improved, and light extraction efficiency of a device is improved.

Alternatively, the first light extraction layer 7 is made of an organic material or an inorganic material (e.g., zinc oxide) having a refractive index greater than 1.5.

Alternatively, the second light extraction layer 8 is made of an organic material or an inorganic material (for example, one of lithium fluoride, silicon nitride, and silicon oxide) having a refractive index smaller than that of the first light extraction layer 7. For example, the refractive index of the material of which the second light extraction layer 8 is made may be 1.4 or more.

Alternatively, in other embodiments, the display panel may also include only the first light extraction layer 7 and not the second light extraction layer 8.

Illustratively, referring again to fig. 1, the display panel further comprises an encapsulation layer 9, the encapsulation layer 9 being located at a side of said second light extraction layer 8 remote from the driving backplate 1. Optionally, the encapsulation layer 9 includes at least one of an organic encapsulation sub-layer and an inorganic encapsulation sub-layer. The organic packaging sub-layer can be made of polyimide, polyamide, acrylic resin, phenolic resin and other organic materials. The inorganic packaging sub-layer can be made of inorganic materials such as silicon nitride, silicon oxide, silicon oxynitride and the like.

The structure of the driving back plate 1 is exemplarily described below. Fig. 8 is a schematic cross-sectional structure of a display panel according to an embodiment of the disclosure, and fig. 8 is an enlarged schematic view of a region B in fig. 1. As shown in fig. 8, the driving back plate includes a substrate 11, and a gate layer 12, a gate insulating layer 15, an active layer 14, an interlayer dielectric layer 18, a source drain layer 13, a passivation layer 17, and a planarization layer 16, which are sequentially stacked on the substrate 1.

In other possible embodiments, the driving back plate includes a light shielding layer, a buffer layer, an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, and a source drain layer sequentially stacked on a substrate.

Illustratively, the substrate 11 may be any transparent substrate, such as a glass substrate, a quartz substrate, a plastic substrate, other transparent hard substrate, or other transparent flexible substrate, which may be a single-layer or multi-layer structure. Taking a multilayer structure as an example, the first substrate comprises a first PI (polyimide) layer, a first sub-protection layer, a second PI layer and a second sub-protection layer which are sequentially laminated from bottom to top, wherein the two sub-protection layers are used for protecting the first PI layer and the second PI layer, and damage to the PI layer by a subsequent process is prevented. The second sub-protective layer is also covered with a buffer layer which can block water and oxygen and block alkaline ions.

The gate layer 12 may be a single-layer metal film of aluminum, molybdenum, copper, titanium, or the like, or a multi-layer metal film of molybdenum, aluminum, and molybdenum, or titanium, or the like, stacked in this order, for example.

The source/drain layer 13 may be a single-layer metal film of aluminum, molybdenum, copper, titanium, or the like, or may be a multi-layer metal film of molybdenum layer, aluminum layer, and molybdenum layer, or titanium layer, aluminum layer, and titanium layer, which are sequentially stacked.

The driving back plate may be an LTPO (Low-Temperature Polycrystalline oxide, low Temperature polysilicon oxide) back plate or an LTPS (Low Temperature polysilicon) back plate, for example. Correspondingly, the active layer 14 is made of a low-temperature polysilicon material, a metal oxide semiconductor material such as IGZO (Indium Gallium Zinc Oxide ) or the like, or the active layer 14 is made of a low-temperature polysilicon material.

Illustratively, the gate insulating layer 15, the interlayer dielectric layer 18 and the passivation layer 17 may be made of silicon oxide or silicon nitride, silicon oxynitride, or the like.

Illustratively, the planarization layer 16 is made of an organic insulating material, such as a resin or the like.

Fig. 9 is a schematic cross-sectional structure of a light-emitting layer according to an embodiment of the present disclosure. As shown in fig. 9, when the display panel is an OLED (Organic Light Emitting Diode ) display panel, the light emitting Layer 4 includes a Hole injection Layer (Hole Injection Layer, short HIL) 401, a Hole transport Layer (Hole Transport Layer, short HTL) 402, an electron blocking Layer (Electron Blocking Layer, short EBL) 403, a light emitting material Layer 404, a Hole Blocking Layer (HBL) 405, an electron transport Layer (Electron Transport Layer, short ETL) 406, and an electron injection Layer (Electron Injection Layer, short EIL) 407, which are sequentially stacked in a direction from near the first electrode 2 to far from the first electrode 2.

Alternatively, the hole injection layer 401 may be made of an inorganic oxide, such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide, and may be a dopant of a strong electron-withdrawing system, such as hexacyanohexaazatriphenylene.

Alternatively, the hole transport layer 402 may be made of arylamine, dimethylfluorene, carbazole, or the like.

Alternatively, the electron blocking layer 403 may be made of arylamine, carbazole, or the like having good hole transport characteristics.

Alternatively, the light-emitting material layer 404 may be made of pyrene derivative, anthracene derivative, fluorene derivative, perylene derivative, styrylamine derivative, metal complex, or the like.

Alternatively, the hole blocking layer 405 and the electron transport layer 406 may be made of aromatic heterocyclic compounds, such as imidazole derivatives, e.g., benzimidazole derivatives, imidazopyridine derivatives, benzimidazole phenanthridine derivatives, etc.; pyrimidine derivatives, triazine derivatives and other oxazine derivatives; compounds containing a nitrogen-containing six-membered ring structure such as quinoline derivatives, isoquinoline derivatives and phenanthroline derivatives (including compounds having a phosphine oxide substituent on the heterocycle).

Optionally, the electron injection layer 407 is made of alkali metal and metal, such as LiF, yb, mg, ca, or their compounds, etc.

Fig. 10 is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of the disclosure. As shown in fig. 10, the method includes:

in step S1, a driving back plate is provided.

In step S2, a light emitting functional layer is fabricated on the driving back plate, where the light emitting functional layer includes a pixel defining layer and a plurality of light emitting units.

The pixel definition layer comprises a conductive part, a plurality of light emitting units are respectively positioned in one opening, each light emitting unit comprises a first electrode, a light emitting layer and a second electrode which are sequentially laminated along the direction far away from the driving backboard, the second electrode of each light emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the light emitting units are insulated from the conductive part.

Fig. 11 is a first partial flowchart of a method for manufacturing a display panel according to an embodiment of the disclosure, and fig. 12 is a second partial flowchart of a method for manufacturing a display panel according to an embodiment of the disclosure, in which the display panel shown in fig. 1 can be manufactured. The manufacturing process comprises the following steps:

in the first step, as shown in part (a) of fig. 11, a driving back plate 1 is provided, a first conductive material layer is formed on the driving back plate 1 by, for example, deposition, and then patterning is performed on the initial first electrode layer, so as to obtain a plurality of first electrodes 2 distributed in an array.

In a second step, as shown in part (b) of fig. 11, a first insulating-structure sub-layer 60a is formed on the first electrode layer 2 by, for example, deposition or ink-jet.

Third, as shown in part (c) of fig. 11, the first insulating structure sub-layer 60a is patterned to obtain a patterned first insulating structure sub-layer 61a. Optionally, the step includes: PR (Photo Resist) is formed on the first insulating structure sub-layer 60a, PR above the first electrode is reserved through steps of exposure, development, etching and the like, dry etching is performed on the PR-covered first insulating structure sub-layer 60a, part of the first insulating structure layer 60 between the plurality of first electrodes 2 is removed, the patterned first insulating structure sub-layer 61a is obtained, and PR above the patterned first insulating structure sub-layer 61a is removed through wet etching.

Fourth, as shown in part (d) of fig. 11, an initial pixel defining layer 310a is formed on the patterned first insulating structure sub-layer 61a by, for example, sputtering or evaporation, where the initial pixel defining layer 310a is made of a conductive material.

Fifth, as shown in part (e) of fig. 11, an initial first protective layer 100 is formed on the initial pixel defining layer 310a by, for example, deposition.

Sixth, as shown in part (f) of fig. 11, PR is formed on the initial first protective layer 100, and PR located over the first electrode 2 is removed by exposure, development, etching, and the like.

Seventh, as shown in part (g) of fig. 11, the initial first protective layer 100 covered with PR is dry etched to remove a portion of the initial first protective layer 100 located above the plurality of first electrodes 2 and the patterned first insulating structure sub-layer 61a, forming the first protective layer 10. And removing the patterned part of the first insulating structure sub-layer 61a located on the plurality of first electrodes 2 to form a part 6a of the plurality of first insulating structures 6. The PR over the first protective layer 10 is then removed by wet etching.

Eighth, as shown in part (h) of fig. 11, the second insulating structure sub-layer 60b is formed by, for example, deposition or ink-jet. PR is formed on the second insulating-structure sub-layer 60b, and the second insulating-structure sub-layer 60b covered with PR is etched by, for example, dry etching, by exposing, developing, etching, or the like, leaving PR over a portion 6a of the first insulating structure 6.

A ninth step of removing a portion of the second insulating structure sub-layer 60b located between the upper sides of the plurality of first electrodes 2 and removing the second insulating structure sub-layer 60b located above the plurality of first electrodes 2, as shown in part (i) of fig. 11, to obtain another portion 6b of the first insulating structure 6. A portion 6a of the first insulating structure 6 and another portion 6b of the first insulating structure 6 constitute the first insulating structure 6. The PR over the first insulating structure 6 is then removed, for example by wet etching.

Tenth, as shown in part (j) of fig. 12, a first light emitting layer material 410 is deposited on the first electrode 2 by, for example, deposition. PR is formed over the first light emitting layer material 410 by, for example, deposition and only PR at the first light emitting region is retained by development etching.

In the eleventh step, as shown in part (k) of fig. 12, the first light emitting layer 41 is formed by, for example, dry etching while leaving only the first light emitting layer material 410 located in the first light emitting region.

A twelfth step, as shown in part (l) of fig. 12, sequentially forms the second light emitting layer 42 and the third light emitting layer 43 in a similar manner to the tenth and eleventh steps.

A thirteenth step is to deposit a layer of the second conductive material, as shown in part (m) of fig. 12, by means of, for example, sputtering or evaporation. Since the sidewall of the protective layer 33 is steep or the protective layer 33 is thick, the second conductive material layer is broken at the protective layer 33, forming a plurality of second electrodes 32 and conductive structures 33.

Alternatively, in this step, the conductive structure 33 located at the side wall of the protective layer 33 may also be removed by etching or the like.

A fourteenth step, as shown in part (n) of fig. 12, sequentially deposits the first light extraction layer 7 and the second light extraction layer 8 by, for example, deposition.

A fifteenth step of forming an encapsulation layer 9 on a side of the second light extraction layer 8 remote from the substrate base plate 1, as shown in part (o) of fig. 12. The method comprises the following steps: the first packaging structure on the pixel defining layer 10 is formed by a deposition method, the second packaging structure on one side of the second electrode far away from the driving backboard and on the light emitting area is formed by an ink-jet method, the first packaging structure and the second packaging structure are connected into an integral structure, and the surface of the first packaging structure far away from the substrate is flush with the surface of the second packaging structure far away from the substrate.

Optionally, the patterning process includes photoresist coating, exposure, development, etching, stripping, and the like.

Illustratively, in the process of manufacturing the display panel shown in fig. 3, in comparison with the process of manufacturing the display panel shown in fig. 1, in the thirteenth step, since the side wall of the protective layer 33 is gentle or the protective layer 33 is thin, the conductive structure 33 is connected to the second electrode 32 at the side wall of the protective layer 5.

Illustratively, in the process of manufacturing the display panel shown in fig. 5, the insulating structure 6 does not need to be manufactured, as compared with the process of manufacturing the display panel shown in fig. 1. In the fourth step, it is necessary to sequentially form an initial first pixel defining sub-layer made of an insulating material and an initial second pixel defining sub-layer made of a conductive material, respectively corresponding to the insulating portion 31b and the conductive portion 31a.

Illustratively, in the process of manufacturing the display panel shown in fig. 6, in comparison with the process of manufacturing the display panel shown in fig. 1, it is necessary to sequentially form the initial first pixel defining sub-layer made of an insulating material and the initial second pixel defining sub-layer made of a conductive material in the fourth step, respectively corresponding to the insulating portion 31b and the conductive portion 31a.

The embodiment of the disclosure also provides a display device, which comprises any one of the display panels and a power supply circuit, wherein the power supply circuit is used for supplying power to the display panels.

The display device provided by the embodiment of the disclosure may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like.

The display device has the same effects as the aforementioned display panel, and will not be described herein.

The foregoing is merely an alternative embodiment of the present disclosure, and is not intended to limit the present disclosure, any modification, equivalent replacement, improvement, etc. that comes within the spirit and principles of the present disclosure are included in the scope of the present disclosure.

Claims

1. A display panel, characterized in that the display panel comprises a driving backboard and a light-emitting functional layer positioned on the driving backboard, wherein the light-emitting functional layer comprises a pixel definition layer and a plurality of light-emitting units;

the pixel definition layer is provided with a plurality of openings distributed in an array, and comprises a conductive part;

the light emitting units are respectively located in one opening, each light emitting unit comprises a first electrode, a light emitting layer and a second electrode which are sequentially stacked along the direction away from the driving backboard, the second electrode of each light emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the light emitting units are insulated from the conductive part.

2. The display panel according to claim 1, wherein the pixel defining layer includes only the conductive portion, the light emitting functional layer further includes a plurality of insulating structures, the plurality of insulating structures are in one-to-one correspondence with the plurality of light emitting units, and the insulating structures are located in the same opening as the corresponding light emitting units and surround the first electrodes of the corresponding light emitting units.

3. The display panel of claim 2, wherein the insulating structure further surrounds the light emitting layer of the corresponding light emitting unit, and a thickness of the insulating structure is greater than a sum of thicknesses of the first electrode and the light emitting layer.

4. A display panel according to claim 3, characterized in that the insulating structure has a radial dimension of 1 μm to 10 μm.

5. The display panel according to claim 1, wherein the pixel defining layer further includes an insulating portion, and the insulating portion is located at a side of the conductive portion near the driving back plate.

6. The display panel according to claim 5, wherein a thickness of the insulating portion is larger than a sum of thicknesses of the first electrode and the light emitting layer.

7. The display panel according to any one of claims 1 to 6, further comprising a protective layer on a side of the pixel defining layer remote from the driving back plane.

8. The display panel according to claim 7, wherein the thickness of the protective layer is 0.5 to 1 μm.

9. The display panel of claim 8, wherein the protective layer comprises a first stripe structure between two adjacent light emitting units, the first stripe structure having opposite first and second sidewalls, a plane in which the first sidewall and the second sidewall intersect at a side of the protective layer away from the driving back plate.

10. The display panel of claim 8 or 9, further comprising a conductive structure co-layered with and connected to the second electrode, the conductive structure being located on a side of the protective layer remote from the driving backplate.

11. The display panel according to any one of claims 1 to 6 and 8 to 9, wherein the thickness of the conductive portion is 0.5 μm to 1 μm.

12. The display panel according to any one of claims 1 to 6 and 8 to 9, wherein the conductive portion is made of a metal material.

13. The display panel according to any one of claims 1 to 6 and 8 to 9, wherein the first electrode includes a first sub-layer, a second sub-layer, and a third sub-layer sequentially stacked on the driving back plate;

the first sub-layer and the third sub-layer are made of transparent conductive materials, and the second sub-layer is made of metal materials.

14. A method for manufacturing a display panel, the method comprising:

providing a driving backboard;

manufacturing a light-emitting functional layer on the driving backboard, wherein the light-emitting functional layer comprises a pixel definition layer and a plurality of light-emitting units;

the pixel definition layer comprises a conductive part, a plurality of light emitting units are respectively positioned in one opening, each light emitting unit comprises a first electrode, a light emitting layer and a second electrode which are sequentially stacked along the direction far away from the driving backboard, the second electrode of each light emitting unit is connected with the conductive part, the thickness of the conductive part is larger than that of the second electrode, and the first electrodes of the light emitting units are insulated from the conductive part.

15. A display device comprising a power supply circuit and the display panel according to any one of claims 1 to 13, the power supply circuit supplying power to the display panel.