CN110943113A

CN110943113A - Array substrate, OLED display panel and preparation method thereof

Info

Publication number: CN110943113A
Application number: CN201911174312.3A
Authority: CN
Inventors: 夏晨
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-03-31

Abstract

The application discloses array substrate, OLED display panel and preparation method thereof, through preparing a layer of silver nanoparticle scattering layer on flexible substrate, utilize annealing to realize the coarsening of particle diameter, utilize the surface plasmon resonance effect and the light scattering performance of silver nanoparticle to increase the extraction to absorbed light and reverberation, improve the efficiency of outer quantum to improve the luminous efficacy of OLED device.

Description

Array substrate, OLED display panel and preparation method thereof

Technical Field

The application relates to the technical field of display, in particular to an array substrate, a bottom-emitting OLED display panel and a preparation method thereof.

Background

In recent years, products manufactured by using Organic Light Emitting Diodes (OLEDs) can achieve a Light Emitting function without backlight, power consumption of the products is reduced, the products are lighter and thinner in appearance, high in color and display accuracy, wide in viewing angle, fast in response, bendable and the like, and therefore the OLED devices are widely applied to display fields of mobile phones, flat panels, televisions and the like.

Fig. 1 is a schematic structural diagram of a conventional OLED display device, which includes a substrate 101, a Thin Film Transistor (TFT) circuit layer 102 disposed on the substrate 101, an OLED light emitting layer 103, and a Thin Film encapsulation layer 104, and further includes an anode, a cathode, and other parts not shown. Since the OLED device realizes a light emitting function by injecting and recombining carriers, the performance of the OLED device is affected by the level of light emitting efficiency, and thus the light emitting efficiency is also one of the main parameters for evaluating the light emitting performance of the OLED display device.

In order to improve the light emission efficiency, research into internal quantum efficiency and external quantum efficiency, which indicate the light emission efficiency, is also being conducted. At present, the research on internal quantum efficiency can make the internal quantum efficiency reach 100% theoretically through the development of phosphor light and thermally activated delayed fluorescent materials in a light emitting layer, and the external quantum efficiency is limited by structures and materials of a waveguide, a substrate, surface plasma and the like, so that the external quantum efficiency is much lower than the internal quantum efficiency, wherein the dominant factor is reflected light loss, so how to reduce the reflection loss of light in a device, improve the external quantum efficiency of the device, and improve the light emitting efficiency of an OLED device is a problem to be faced when improving the performance of the OLED device and an OLED display device.

Disclosure of Invention

The embodiment of the application provides an array substrate, an OLED display panel and a preparation method thereof, which can increase the extraction efficiency of absorbed light and reflected light, thereby enhancing the external quantum efficiency and solving the technical problem that the external quantum efficiency is greatly lost due to the limitation of factors such as waveguide and substrate of the existing OLED display panel.

The embodiment of the application provides an array substrate, which comprises a flexible substrate, a light extraction layer and a TFT device layer, wherein the light extraction layer and the TFT device layer are prepared on the bottom side of the flexible substrate;

the light extraction layer includes: buffer layer, scattering layer and planarization layer.

The scattering layer is located between the buffer layer and the flat layer, and the scattering layer extracts absorbed light and reflected light through a surface plasma resonance effect, so that external quantum efficiency is improved.

In some embodiments, the scattering layer is a silver nanoparticle layer and is made by an evaporation process; after the scattering layer is annealed, under the modification effect of the surface energy of the buffer layer, nanoparticles are aggregated, the particle size is increased, and for nanoparticles with large particle size and smaller particle size, the nanoparticles with large particle size have higher scattering efficiency.

In some embodiments, the buffer layer covers the flexible substrate, is prepared by coating and is made of PEDOT: PSS (polyethylene dioxythiophene-polystyrene sulfonic acid), and can play a role in fixing Ag nanoparticles and simultaneously facilitate nucleation and growth of the Ag nanoparticles because the sulfur-containing group of the PEDOT: PSS can form a complex bond with Ag atoms.

In some embodiments, the planarization layer is located outside the buffer layer, covers the scattering layer, and contacts with the buffer layer at the particle gap of the scattering layer, the planarization layer can ensure the flatness of other film layers on the scattering layer, the planarization layer is made of organic photoresist such as SU-8 and Polyimide (PI), and the planarization layer is manufactured by using a coating process.

In some embodiments, the light extraction layer is located between the flexible substrate and the TFT device layer.

In some embodiments, the light extraction layer is located on a side of the flexible substrate away from the TFT device layer.

The present application also provides an OLED display panel, including: the array substrate, the OLED device and the packaging layer are prepared on the array substrate.

In some embodiments, the OLED device is located on a side of the TFT device layer, away from the light extraction layer. The OLED device is a bottom-emitting OLED device and comprises a first electrode, a light-emitting layer and a second electrode; the first electrode is an anode and is made of transparent Indium Tin Oxide (ITO); the second electrode is a cathode, and the material is a high-reflection metal material, such as one or more of gold, silver and aluminum.

The OLED device can further comprise any one or more layers of a hole injection layer, an electron injection layer, a hole transport layer and an electron transport layer besides the first electrode, the light-emitting layer and the second electrode.

The application also provides a manufacturing method of the array substrate, which comprises the following steps:

s1: providing a glass substrate, and preparing a flexible substrate layer on the glass substrate, wherein the thickness of the flexible substrate layer is 10-15 microns;

s2: preparing a buffer layer on the flexible substrate layer by adopting a coating process, wherein the thickness of the buffer layer is 1-1.5 mu m;

s3: preparing a silver nanoparticle layer on the buffer layer by adopting an evaporation process to form a scattering layer, wherein the thickness of the scattering layer is 10-12 nm;

s4: placing the structure prepared in the step S3 into a furnace for low-temperature annealing treatment, wherein the temperature is 120-180 ℃, the duration is 5-15 minutes, and the particle size of the silver nanoparticles of the scattering layer is increased to about 50-150 nm under the surface energy modification effect of the buffer layer to obtain a large-particle-size scattering layer;

s5: preparing a flat layer on the scattering layer by adopting a coating process, wherein the thickness of the flat layer is 1-1.5 mu m;

s6: preparing a TFT device layer; according to the position of the TFT device layer, the step S6 can be divided into:

s61: preparing the TFT device layer on the flat layer;

s62: and preparing the TFT device layer on one side of the flexible substrate far away from the light extraction layer.

And sequentially preparing an electrode layer, a luminescent layer and other film layers on the array substrate to obtain the display panel with the array substrate. Specifically, the manufacturing method of the display panel comprises the following steps:

s1: providing a glass substrate, and preparing the array substrate on the glass substrate;

s2: sequentially preparing a first electrode, a light-emitting layer, a second electrode and an encapsulation layer on the TFT device layer so as to obtain the OLED display panel; the first electrode is a transparent anode, the second electrode is a metal cathode, and the thickness of the anode and the cathode is 50-100 nm.

In some embodiments, the scattering layer material is silver nanoparticles; the flexible substrate material is PI (polyimide) or PET (polyester material); the preparation process of the film layer is not limited to a coating mode and an evaporation mode, and other preparation processes can be selected according to actual needs, such as: gas phase method, liquid phase method, etc.

This application is to OLED display panel light energy receive absorption or reflection between the layer, or waveguide effect influences, leads to the outer quantum efficiency of display panel low, and the technical problem that light-emitting efficiency is poor through increasing the light extraction layer in array substrate, realizes the improvement to external quantum efficiency. The light extraction layer is arranged on the emergent path of the emergent light, when the emergent light acts on the silver nanoparticles and generates a surface plasma resonance effect, the light equivalent to the plasma oscillation frequency can be absorbed or scattered, the scattered light can enter the OLED device at different angles, the optical path of the light transmitted in the device is increased, the possibility of light emission is improved, the external quantum efficiency is improved, and the improvement effect is about 10%.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a conventional OLED display panel.

Fig. 2 is a schematic structural diagram of a first array substrate according to an embodiment of the present disclosure;

fig. 3A to 3F are schematic views illustrating a preparation process of an array substrate according to an embodiment of the present disclosure;

fig. 4 is a flowchart illustrating a method for manufacturing an array substrate according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a second array substrate according to an embodiment of the present disclosure.

Fig. 6 is a schematic structural diagram of a first OLED display panel according to an embodiment of the present disclosure;

fig. 7 is a flowchart illustrating a process for manufacturing an OLED display panel according to an embodiment of the present disclosure.

Fig. 8 is a schematic structural diagram of a second OLED display panel according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact of the first and second features, or may comprise contact of the first and second features not directly but through another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

In the OLED device, holes and electrons are recombined in the light emitting layer to form light energy, and the light energy is affected by the following factors to have different losses when being transmitted to form emergent light, which mainly appears in three aspects:

firstly, the transmittance of each interface affects the loss of light energy, and as the light energy is transmitted from the light emitting layer of the OLED device to the surface of the OLED display panel to form emergent light, the light energy needs to pass through each film layer, the passing path is the transmission path of the emergent light, and different transmittances of different film layers can cause different degrees of loss on the light energy;

secondly, besides the light energy forms emergent light through each interface with certain transmissivity, a part of the light energy can be absorbed after a certain distance, the absorbed light energy is also a loss for the total light energy, and the longer the transmission distance is, the higher the possibility that the light energy is absorbed is, the larger the loss for the light energy is;

thirdly, in addition to the above two cases, a part of the light energy is guided away, absorbed or transmitted to the side surface of the substrate through the waveguide effect, which also causes a certain degree of loss to the light energy, and the magnitude of the light energy loss is determined by the total reflection angle.

Aiming at the technical problems of low external quantum efficiency and poor light extraction efficiency of the OLED display panel caused by the reasons, the embodiment of the application provides an array substrate, an OLED display panel and a preparation method thereof.

Specifically, please refer to fig. 2, which is a first array substrate provided in an embodiment of the present application, the array substrate includes: the light extraction device comprises a flexible substrate 201, a light extraction layer 202 and a TFT device layer 203, wherein the light extraction layer 202 and the TFT device layer 203 are prepared on the flexible substrate 201. The light extraction layer 202 includes a buffer layer 207, a scattering layer 208, and a planarization layer 209. The buffer layer 207 covers the flexible substrate 201 and is made of PEDOT PSS materials, and when the scattering layer 208 is annealed, the buffer layer 207 can play a role in modifying surface energy, so that the scattering layer 208 is more beneficial to forming aggregation of nano particles, the nano particles with large particle size are generated, and the scattering layer 208 has higher scattering efficiency.

The flat layer 209 is located on one side of the TFT device layer 203, covers the scattering layer 208, and at the gap between each nanoparticle of the scattering layer 208, the flat layer 209 is in contact with the buffer layer 207, and the contact surface between the flat layer 209 and the TFT device layer 203 is a plane, so as to ensure the flatness of each film layer on the scattering layer 208.

The scattering layer 208 is located between the buffer layer 207 and the flat layer 209, and is made of silver nanoparticles, so that in order to make the scattering layer 208 have higher scattering efficiency, the scattering layer 208 needs to be annealed, and the annealed scattering layer has a larger nanoparticle size, a lower light absorption rate and a better scattering efficiency than the untreated scattering layer.

Fig. 3A to 3F are schematic diagrams illustrating a preparation process of an array substrate according to an embodiment of the present disclosure, and fig. 4 is a flowchart illustrating a preparation process of an array substrate according to an embodiment of the present disclosure, including the following steps:

s1: providing a glass substrate 301, preparing a flexible base layer 302 on the glass substrate 302 by adopting a coating process, wherein the thickness of the flexible base layer 302 is 10-15 μm, and obtaining a structural schematic diagram shown in fig. 3A;

s2: preparing a buffer layer 307 on the flexible substrate layer 302 by adopting a coating process, wherein the buffer layer 307 is made of PEDOT (Poly ethylene glycol ether ketone) PSS (polyethylene terephthalate) and has a thickness of 1-1.5 mu m, and a structural schematic diagram shown in FIG. 3B is obtained;

s3: preparing a silver nanoparticle layer on the buffer layer 307 by adopting an evaporation process to form a scattering layer 308, wherein the thickness of the scattering layer 308 is 10-12 nm, and obtaining a structural schematic diagram shown in fig. 3C;

s4: placing the structure prepared in the step S3 into a furnace to perform low-temperature annealing treatment, wherein the temperature is 120-180 ℃, the duration is 5-15 minutes, and the particle size of the silver nanoparticles of the scattering layer 308 is increased to about 50-150 nm under the surface energy modification effect of the buffer layer 307, so as to obtain a large-particle-size scattering layer 308, as shown in fig. 3D;

s5: preparing a flat layer 309 on the scattering layer 308 by adopting a coating process, wherein the flat layer 309 is made of an organic photoresist and has a thickness of 1-1.5 μm, so as to obtain a structural schematic diagram shown in fig. 3E;

s6: the TFT device layer 303 is fabricated on the planarization layer 309 as shown in fig. 3F.

Referring to fig. 5, which is a schematic structural diagram of a second array substrate provided in this embodiment of the present application, where the symbols in the diagram are the same as those in fig. 2, in the schematic structural diagram shown in fig. 5, the light extraction layer 202 is located on a side of the flexible substrate 201 away from the TFT device layer 203, and an OLED device may be prepared on the TFT device layer 203.

Please refer to fig. 6, which is a schematic structural diagram of a first OLED display panel according to an embodiment of the present disclosure, including a glass substrate 601, a first electrode 604, a light emitting layer 605, a second electrode 606, an encapsulation layer 610, and the array substrate structure shown in fig. 2; the array substrate structure comprises a flexible substrate 602, a TFT device layer 603 and a light extraction layer; the light extraction layer includes a buffer layer 607, a scattering layer 608, and a planarization layer 609. The encapsulation layer 610 may be a glass cover plate or a thin film encapsulation structure; the thin film packaging structure comprises a stacked structure consisting of a first inorganic packaging layer, an organic packaging layer, a second inorganic packaging layer and the like.

The first electrode 604 is an anode electrode made of transparent Indium Tin Oxide (ITO), and the second electrode 606 is a cathode electrode made of a highly reflective metal material, such as one or a combination of gold, silver, and aluminum.

The OLED display panel may further include any one or more layers of a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer, in addition to the array substrate 601, the light extraction layer, the first electrode 604, the light emitting layer 605, the second electrode 606, and the encapsulation layer 610.

The array substrate structure of the OLED display panel can be the structure shown in FIG. 5 in addition to the structure shown in FIG. 2, when the structure shown in FIG. 5 is adopted, the OLED device is prepared on the TFT device layer 603, the OLED display panel can be manufactured by utilizing the existing preparation process, the preparation process is simplified, and the external quantum efficiency is improved.

The light extraction layer is arranged on the emergent path of the emergent light, when the emergent light acts on the surface of the silver nano-particles, photons induce surface free electrons to perform offset movement, the electrons can be inhibited from moving under the influence of coulomb force to form electromagnetic waves in reciprocating motion, an enhanced electromagnetic field is generated at the junction, the free electrons in the nano-particles are excited by an oscillating electric field to oscillate in a collective mode to generate a surface plasma resonance effect, light with the same oscillation frequency as that of plasma can be absorbed or scattered, the scattered light can enter the OLED device layer at different angles, the optical path of light transmitted in the device is increased, the possibility of light emission is improved, and the external quantum efficiency is improved.

For the structural schematic diagram of the OLED display panel shown in fig. 6, the preparation process of the OLED display panel is shown in fig. 7, and includes the following steps:

s1: providing a glass substrate 601, and preparing a flexible base layer 602 on the glass substrate 601 by adopting a coating process, wherein the thickness of the flexible base layer 602 is 10-15 μm;

s2: preparing a buffer layer 607 on the flexible substrate layer 602 by adopting a coating process, wherein the buffer layer 607 is made of PEDOT (polyethylene glycol terephthalate) PSS (polystyrene) and has a thickness of 1-1.5 mu m;

s3: preparing a silver nanoparticle layer on the buffer layer 607 by adopting an evaporation process to form a scattering layer 608, wherein the thickness of the scattering layer 608 is 10-12 nm;

s4: placing the structure prepared in the step S3 into a furnace to perform low-temperature annealing treatment, wherein the temperature is 150 ℃, the duration is 10 minutes, and the particle size of the silver nanoparticles of the scattering layer 608 is increased to about 50-150 nm under the surface energy modification effect of the buffer layer 607, so as to obtain a large-particle-size scattering layer 608;

s5: preparing a flat layer 609 on the scattering layer 608 by adopting a coating process, wherein the flat layer 609 is made of an organic photoresist and has a thickness of 1-1.5 mu m;

s6: sequentially preparing a TFT device layer 603, a first electrode 604, a light-emitting layer 605, a second electrode 606 and an encapsulation layer 610 on the flat layer 609, thereby obtaining the OLED display panel; the thickness of the first electrode 604 and the second electrode 606 is 50-100 nm.

The first electrode 604 is an anode electrode made of transparent Indium Tin Oxide (ITO), and the second electrode 605 is a cathode electrode made of a highly reflective metal material, such as one or a combination of gold, silver, and aluminum.

The flexible substrate layer 602 material may be PI or PET. The encapsulation layer 610 may be a glass cover plate or a thin film encapsulation structure; the thin film packaging structure comprises a stacked structure consisting of a first inorganic packaging layer, an organic packaging layer, a second inorganic packaging layer and the like.

The OLED display panel manufacturing process can adopt different manufacturing sequences according to different substrate structures, the flow chart provided in the present invention is only an exemplary illustration, and is not intended to limit the manufacturing sequence, and a person skilled in the art can adjust the manufacturing sequence according to actual needs.

The annealing treatment and particle size variation data table of the present invention is shown in table 1.

Experiment number	Annealing temperature (. degree.C.)	Annealing time (min)	Diameter of silver nanoparticle (nm)
				1	120	5	25
2	120	10	98
				3	120	15	75
4	150	5	105
				5	150	10	150
6	150	15	120
				7	180	5	60
8	180	10	80
				9	180	15	50

As can be seen from table 1, different annealing temperatures and annealing durations have different effects on the diameters of the silver nanoparticles, and under the condition of a certain annealing temperature, the annealing duration is 10 minutes, and the diameters of the obtained silver nanoparticles are larger than the diameters of the silver nanoparticles when the annealing duration is 5 minutes and 15 minutes; under the condition of a certain annealing time, the diameter of the silver nano-particles is larger than the diameters of the silver nano-particles at the annealing temperatures of 150 ℃ and 180 ℃.

Therefore, in this example, the annealing temperature is 150 ℃ and the annealing time is 10 minutes, and the particle size of the scattering layer obtained at this time is the largest; in addition, different annealing temperature and time can be set to obtain scattering layers with different particle sizes, and the related technical personnel can properly change the annealing temperature and time according to the actual needs to meet different particle size requirements.

Referring to fig. 8, which is a schematic structural diagram of a second OLED display panel provided in an embodiment of the present disclosure, where the reference numerals are the same as those in fig. 6, in this embodiment, the light extraction layer is located on the glass substrate 601, the buffer layer 607 covers the glass substrate 601, the scattering layer 608 is annealed with the buffer layer 607 to obtain a scattering layer 608 with a large particle size, and a planarization layer 609 is prepared on the scattering layer 608 to ensure the planarity of the flexible substrate 602, the TFT device layer 603, the OLED device, and the encapsulation layer on the planarization layer 609.

The thickness and the preparation process of each film layer given in this embodiment are only for helping understanding the present invention, and are not limited to the present invention, and a person skilled in the art may change the thickness and the preparation process according to actual needs, for example, the preparation process of the film layer is not limited to the coating method and the evaporation method, and other preparation processes may be selected according to actual needs, for example: gas phase method, liquid phase method, etc.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

The array substrate, the OLED display panel and the manufacturing method thereof provided in the embodiments of the present application are described in detail above, and specific examples are applied herein to explain the principles and embodiments of the present application, and the description of the embodiments above is only used to help understand the technical solutions and core ideas of the present application; those of ordinary skill in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. An array substrate, comprising: the TFT light extraction device comprises a flexible substrate, a TFT device layer arranged on the flexible substrate and a light extraction layer arranged on one side of the flexible substrate;

the light extraction layer includes: the light-emitting diode comprises a buffer layer, a flat layer and a scattering layer positioned between the buffer layer and the flat layer;

the light extraction layer is positioned on a transmission path of light emitted by the OLED device, and the scattering layer extracts the absorbed light and the reflected light through a surface plasmon resonance effect, so that the luminous efficiency of the OLED device is improved.

2. The array substrate of claim 1, wherein the light extraction layer is between the flexible substrate and the TFT device layer.

3. The array substrate of claim 1, wherein the light extraction layer is located on a side of the flexible substrate away from the TFT device layer.

4. The array substrate of claim 1, wherein the scattering layer is a silver nanoparticle layer, and the planarization layer is PEDOT PSS.

5. The array substrate of claim 1, wherein the planarization layer covers the scattering layer and contacts the planarization layer at gaps between particles of the scattering layer.

6. An OLED display panel, comprising: the array substrate as claimed in claim 1 to 5, an OLED device on the array substrate, and an encapsulation layer.

7. The OLED display panel of claim 6, wherein the OLED device is a bottom-emitting OLED device on a side of the TFT device layer remote from the light extraction layer.

8. The manufacturing method of the array substrate is characterized by comprising the following steps:

s1: preparing a flexible substrate layer on a glass substrate;

s2: preparing a buffer layer on the flexible substrate layer;

s3: preparing a scattering layer on the buffer layer;

s4: carrying out low-temperature annealing treatment on the structure prepared in the step S3 to obtain a large-particle-size scattering layer;

s5: preparing a flat layer on the scattering layer;

s6: and preparing the TFT device layer on the flat layer or on the side of the flexible substrate far away from the light extraction layer.

9. The method for manufacturing the array substrate according to claim 8, wherein the scattering layer is subjected to a roughening treatment of the nanoparticle size by a low temperature annealing treatment process.

10. The method for manufacturing the array substrate according to claim 9, wherein the low temperature annealing treatment temperature is 120 ℃ to 180 ℃ and the duration is 5 minutes to 15 minutes.