Flexible display device and manufacturing method thereof

A flexible display device includes: an organic light emitting layer for emitting light; a cathode electrode layer disposed on the organic light emitting layer; and a cavity region located between a plane where the cathode electrode layer is located and the organic light emitting layer.

TECHNICAL FIELD

The present application relates to the field of display technology, and particularly to a flexible display device and a manufacturing method thereof.

BACKGROUND

At present, a flexible display device is generally made of a multilayer structure. When the flexible display device is bent, failure of a layer is often caused by stress concentration.

SUMMARY

In view of the above, the embodiments of the present application provide a flexible display device and a manufacturing method thereof which solve the problems including easy peeling between a cathode electrode layer and an organic light emitting layer.

An embodiment of the present application provides a flexible display device, including an organic light emitting layer for emitting light; a cathode electrode layer disposed on the organic light emitting layer; and a cavity region located between a plane where the cathode electrode layer is located and the organic light emitting layer.

The cathode electrode layer includes a protrusion extending to the organic light emitting layer and electrically connected with the organic light emitting layer.

The cathode electrode layer includes a first cathode electrode portion and a second cathode electrode portion, the first cathode electrode portion and the second cathode electrode portion are superposed. The first cathode electrode portion is disposed on a surface of the organic light emitting layer, and the first cathode electrode portion includes a first protrusion as the protrusion extending to the second cathode electrode portion and electrically connected with the second cathode electrode portion. Alternatively, the first cathode electrode portion is disposed on a surface of the organic light emitting layer, and the second cathode electrode portion includes a second protrusion as the protrusion extending to the first cathode electrode portion and electrically connected with the first cathode electrode portion. Alternatively, the first cathode electrode portion is disposed on a surface of the organic light emitting layer, and the first cathode electrode portion includes a first protrusion as the protrusion extending to the second cathode electrode portion, the second cathode electrode portion includes a second protrusion extending to the first cathode electrode portion, and the first protrusion is electrically connected with the second protrusion.

A part of the first cathode electrode portion located on the surface of the organic light emitting layer has a width of 3 to 20 μm, and a thickness of the first cathode electrode portion is 20 nm.

The flexible display device includes a pixel defining layer surrounding the organic light emitting layer; an anode electrode layer located on a non-light emitting side of the organic light emitting layer; an encapsulating layer superposed on the surface of the cathode electrode layer away from the organic light emitting layer; and an adhesive material disposed between the cathode electrode layer and the pixel defining layer or between the encapsulating layer and the pixel defining layer.

The cathode electrode layer includes a region in partial contact with the pixel defining layer.

A surface of the pixel defining layer on a same side as the cathode electrode layer includes at least one groove or gap, and the adhesive material is filled in the at least one groove or gap.

An embodiment of the present application also provides a method for manufacturing a flexible display device, including: preparing a cathode electrode layer, a surface of the cathode electrode layer including a protrusion; and electrically connecting the surface of the cathode electrode layer including the protrusion with an organic light emitting layer to form a cavity region between a plane where the cathode electrode layer is located and the organic light emitting layer.

An embodiment of the present application also provides a method for manufacturing a flexible display device, including: preparing a first cathode electrode portion on a surface of the organic light emitting layer; and preparing a second cathode electrode portion, and electrically connecting the second cathode electrode portion with the first cathode electrode portion to form a cavity region between a plane where the second cathode electrode portion is located and the organic light emitting layer.

The first cathode electrode portion includes a first protrusion for electrically connecting with the second cathode electrode portion; or the second cathode electrode portion includes a second protrusion for electrically connecting with the first cathode electrode portion; or, the first cathode electrode portion includes a first protrusion for electrically connecting with the second cathode electrode portion; and the second cathode electrode portion includes a second protrusion for electrically connecting with the first cathode electrode portion.

Before preparing a first cathode electrode portion on a surface of an organic light emitting layer, the manufacturing method includes: providing or preparing a first substrate; preparing an anode electrode layer; preparing a pixel defining layer that exposes the anode electrode layer; and preparing the organic light emitting layer on the exposed anode electrode layer.

Before electrically connecting the second cathode electrode portion with the first cathode electrode portion, the manufacturing method includes: preparing an adhesive material on a surface of the pixel defining layer.

A surface of the pixel defining layer includes a groove or a gap; and before electrically connecting the second cathode electrode portion with the first cathode electrode portion, the manufacturing method includes: preparing an adhesive material in the groove or the gap.

After electrically connecting the second cathode electrode portion with the first cathode electrode portion, the manufacturing method includes: peeling off the first substrate.

The preparing a second cathode electrode portion includes: providing or preparing a second substrate; preparing an encapsulation layer on the second substrate; and preparing the second cathode electrode portion on the encapsulation layer.

After electrically connecting the second cathode electrode portion with the first cathode electrode portion, the manufacturing method includes: peeling off the second substrate.

The embodiments of the present application provide a flexible display device and a manufacturing method thereof. By providing the cavity region between the plane where the cathode electrode layer is located and the organic light emitting layer, when the flexible display device is bent, the cavity region can avoid transmission of bending stress and release the bending stress, thereby effectively preventing stress concentration of the cathode electrode layer and the organic light emitting layer, avoiding defects of the cathode electrode layer or the organic light emitting layer, such as cracking, peeling and so on, and improving reliability performance of the flexible display device.

DETAILED DESCRIPTION

FIG. 1shows a structural schematic diagram of a flexible display device according to an embodiment of the present application.

As shown inFIG. 1, the flexible display device includes an organic light emitting layer3for emitting light, a cathode electrode layer2disposed on a light emitting side of the organic light emitting layer3, and a cavity region6located between a plane where the cathode electrode layer2is located and the organic light emitting layer3. The plane where the cathode electrode layer2is located may be understood as a plane of preparing the cathode electrode layer2or a relatively flat plane of the cathode electrode layer2. The organic light emitting layer3may correspond to light emitting pixels which emit a red light, a green light or a blue light, and the light emitting color type of the organic light emitting layer3is not specifically limited in the embodiments of the present application. The cathode electrode layer2may completely cover the organic light emitting layer3, or may include a hollow structure on the surface to partially cover the organic light emitting layer3. However, it should be understood that the cathode electrode layer2only need to have an electrical connection relationship with the organic light emitting layer3, and can realize light emission of the flexible display device. The structural form of the cathode electrode layer2is not specifically limited in the embodiments of the present application.

By providing the cavity region6located between the plane where the cathode electrode layer2is located and the organic light emitting layer3, when the flexible display device is bent, the cavity region6can avoid transmission of bending stress and release the bending stress, thereby effectively preventing stress concentration of the cathode electrode layer2and the organic light emitting layer3, avoiding defects of the cathode electrode layer2or the organic light emitting layer3, such as cracking, peeling and so on, and improving reliability performance of the flexible display device.

In an embodiment, the cathode electrode layer2includes a protrusion200extending to the organic light emitting layer3and abutting the organic light emitting layer. The protrusion200is electrically connected with the organic light emitting layer3, so that a part of the cathode electrode layer2is away from the organic light emitting layer3, and the cathode electrode layer2is not completely superposed on the organic light emitting layer3, thereby forming a cavity region6located between the cathode electrode layer2and the organic light emitting layer3. By providing the protrusion200, preparation of the cavity region6can be facilitated. A volume of the cavity region6may be adjusted by adjusting a height of the protrusion200, so that types of the cavity region6are enriched and diverse demands of actual production are meted.

FIG. 2shows a structural schematic diagram of a flexible display device according to an embodiment of the present application.

Referring toFIG. 2, in an embodiment, a cathode electrode layer2may be a structure in which a plurality of layers are electrically connected. For example, in the embodiment of the present application, the cathode electrode layer2includes a first cathode electrode portion201and a second cathode electrode portion202, the first cathode electrode portion201and the second cathode electrode portion202are superposed with each other. The first cathode electrode portion201is disposed on a surface of the organic light emitting layer3, and the first cathode electrode portion201may include a first protrusion (not shown inFIG. 2) extending to the second cathode electrode portion202and electrically connected with the second cathode electrode portion202. Or, the first cathode electrode portion201is disposed on a surface of the organic light emitting layer3, and the second cathode electrode portion202includes a second protrusion2020extending to the first cathode electrode portion201and electrically connected with the first cathode electrode portion201. Or, the first cathode electrode portion201is disposed on a surface of the organic light emitting layer3, the first cathode electrode portion201includes a first protrusion extending to the second cathode electrode portion202, the second cathode electrode portion202includes a second protrusion2020extending to the first cathode electrode portion201, and the first protrusion of the first cathode electrode portion201is electrically connected with the second protrusion2020of the second cathode electrode portion202. Preferably, the first cathode electrode portion201is disposed at the edge of the organic light emitting layer3, which reduces the occlusion of the organic light emitting layer3by the first cathode electrode portion201, thereby avoiding affecting the display effect of the flexible display device. The cathode electrode layer2is divided into the first cathode electrode portion201and the second cathode electrode portion202, the first cathode electrode portion201and the second cathode electrode portion202are electrically connected with each other, and the second cathode electrode portion202and the organic light emitting layer3may not be in contact with each other, which facilitates the fitting of the cathode electrode layer2and the organic light emitting layer3, and reduces the difficulty in completely fitting the cathode electrode layer2and the organic light emitting layer3.

In an embodiment, the surfaces of the electrical connection position of the first cathode electrode portion201and the second cathode electrode portion202are flat and have a same shape. For example, at the electrical connection position, if the surface of the first cathode electrode portion201is rectangular, the surface of the second cathode electrode portion202is also rectangular. In this way, good contact between the first cathode electrode portion201and the second cathode electrode portion202can be ensured. However, it should be understood that the electrical connection surfaces of the first cathode electrode portion201and the second cathode electrode portion202may also not be flat, as long as the first cathode electrode portion201and the second cathode electrode portion202are in contact with each other. The shape of the electrical connection surface of the first cathode electrode portion201and the second cathode electrode portion202may also be circle or other shape, and the shape of the electrical connection surface of the first cathode electrode portion201and the second cathode electrode portion202is not specifically limited in the embodiments of the present application.

In an embodiment, the flexible display device may further include a pixel defining layer4surrounding the organic light emitting layer3, and an anode electrode layer5located on a non-light emitting side of the organic light emitting layer3. When a voltage is applied to the flexible display device, holes output from the anode electrode layer5are combined with electrons output from the cathode electrode layer2on the organic light emitting layer3, so that an organic light emitting device can emit light. Since the organic light emitting layer3is generally prepared by a vapor deposition method, a boundary of the organic light emitting layer3can be defined in advance by providing the pixel defining layer4, thereby facilitating preparation of the organic light emitting layer3.

In an embodiment, the cathode electrode layer2may cover a part of the pixel limiting layer4. As shown inFIG. 2, the cathode electrode layer2may include a region in partial contact with the pixel defining layer4, and the region covers a part of the surface of the pixel defining layer4. The cathode electrode layer2may also include a region in which the cathode electrode layer2covers a part of the pixel defining layer4but is not in contact with the pixel defining layer4. The cathode electrode layer2can ensure good conduction between a lower cathode electrode layer2and an upper cathode electrode layer2when the cathode electrode layer2is a multi-layer electrically connected structure by providing the region in partial contact with the pixel defining layer4.

FIG. 3shows is a structural schematic diagram of a flexible display device according to an embodiment of the present application.

Referring toFIG. 3, in an embodiment, the flexible display device may further include an encapsulation layer1superposed on a surface of the cathode electrode layer2away from the organic light emitting layer3. The encapsulation layer1is mainly used to prevent water vapor and oxygen from immersing into an organic light emitting device, prevent the failure of the organic light emitting device, thereby prolonging the life of the organic light emitting device.

In an embodiment, the flexible display device may further include: an adhesive material7disposed between the cathode electrode layer2and the pixel defining layer4, or an adhesive material7disposed between the encapsulating layer1and the pixel defining layer4. A surface of the pixel defining layer4on a same side as the cathode electrode layer2includes at least one groove41. The adhesive material7may be filled in the at least one groove41. When the cathode electrode layer2may include a region in which the cathode electrode layer2covers a part of the pixel defining layer4but is not in contact with the pixel defining layer4, at least one adhesive material7may be located between the partial region of the cathode electrode layer2and the at least one groove41; or the at least one adhesive material7may also be located between the encapsulation layer1and the at least one groove41, and the at least one adhesive material7is not covered by the cathode electrode layer2. When the cathode electrode layer2is a multi-layer electrically connected structure, a good contact connection between the multi layers of the cathode electrode layer2can be ensured by providing at least one adhesive material7. By providing at least one groove41, the good contact connection between the cathode electrode layer2and the pixel defining layer4can be further ensured, and the gap between the multi layers of the cathode electrode layer2can be avoided, the gap leads to bad contact of the multi layers of the cathode electrode layer2.

It should be understood that in the present embodiment, the groove may be replaced with a gap, i.e., filling the adhesive material in the gap is also consistent with the inventive concept of the present application.

The present application also provides a method for manufacturing a flexible display device.

FIG. 4ashows a schematic flow chart of manufacturing a flexible display device according to an embodiment of the present application.

As shown inFIG. 4a, the preparation method may include the following steps.

S101: a second cathode electrode portion202superposed on a surface of a first module is prepared. A surface of the cathode electrode layer2includes a protrusion200. The cathode electrode layer2may be prepared at one time by a vapor deposition method, and the protrusion200is formed on the surface of the cathode electrode layer2. However, the method for preparing the cathode electrode layer2is not specifically limited in the embodiments of the present application.

S102: the surface of the cathode electrode layer2including the protrusion200is electrically connected with an organic light emitting layer3, to form a cavity region6located between a plane where the cathode electrode layer2is located and the organic light emitting layer3.

Through the above preparing process, the cavity region6is formed. When the flexible display device is bent, the cavity region6can avoid transmission of bending stress and release the bending stress, thereby effectively preventing stress concentration of the cathode electrode layer2and the organic light emitting layer3, avoiding defects of the cathode electrode layer2or the organic light emitting layer3, such as cracking, peeling and so on, and improving reliability performance of the flexible display device.

The present application also provides a method for manufacturing a flexible display device.

FIG. 4bshows a schematic flow chart of manufacturing a flexible display device according to an embodiment of the present application.

As shown inFIG. 4b, the manufacturing method may include the following steps.

S11: as shown inFIG. 5, a first cathode electrode portion201is prepared on a surface of the organic light emitting layer3. Compared with the case where the cathode electrode layer2is prepared on the organic light emitting layer3, the preparation of the first cathode electrode portion201on the surface of the organic light emitting layer3can ensure the firm fitting of the first cathode electrode portion201and the organic light emitting layer3.

The first cathode electrode portion201may be prepared on the upper surface of the organic light emitting layer3by a vapor deposition method, and a Fine Metal Mask (FMM) may be used for vapor deposition to make the first cathode electrode201graphical. The graphical first cathode electrode201is located on the surface of the organic light emitting layer3. In an embodiment, a part of the first cathode electrode portion201on the surface of the organic light emitting layer3has a width of in a range from 3 to 20 μm. However, the width of the portion may be determined according to a size of sub pixel, which is not specifically limited in the embodiment of the present application. In an embodiment, a thickness of the first cathode electrode portion201may be 20 nm, which is not specifically limited in the embodiment of the present application.

S12: as shown inFIG. 6, a first module in which a surface includes the second cathode electrode portion202is prepared. Similarly to the method of preparing the first cathode electrode portion201, the second cathode electrode portion202may also be prepared by a vapor deposition method, and an FMM may be used for vapor deposition to make the second cathode electrode202graphical.

S13: as shown inFIG. 2, the second cathode electrode portion202and the first cathode electrode portion201are electrically connected to form a cavity region6located between a plane where the second cathode electrode portion202is located and the organic light emitting layer3.

The first cathode electrode portion201may include a first protrusion (not shown) extending to the second cathode electrode portion202and electrically connected with the second cathode electrode portion202. Or, the first cathode electrode portion201is disposed on a surface of the organic light emitting layer3, and the second cathode electrode portion202includes a second protrusion2020extending to the first cathode electrode portion201and electrically connected with the first cathode electrode portion201. Or, the first cathode electrode portion201is disposed on a surface of the organic light emitting layer3, the first cathode electrode portion201includes a first protrusion extending to the second cathode electrode portion202, the second cathode electrode portion202includes a second protrusion2020extending to the first cathode electrode portion201. The first protrusion of the first cathode electrode portion201is electrically connected with the second protrusion2020of the second cathode electrode portion202.

The second cathode electrode202and the first cathode electrode201may be electrically connected by a splicing process. However, the specific electrical connection manner of the second cathode electrode portion202and the first cathode electrode portion201is not limited in the embodiments of the present application.

In the embodiments of the present application, the cathode electrode layer2is prepared stepwise, i.e., the first cathode electrode portion201and the second cathode electrode portion202are separately prepared, and then the first cathode electrode portion201and the second cathode electrode portion202are electrically connected. Through the above-mentioned preparing process, the cavity region6is formed. When the flexible display device is bent, the cavity region6can avoid transmission of bending stress and release the bending stress, thereby effectively preventing stress concentration of the cathode electrode layer2and the organic light emitting layer3, avoiding defects of the cathode electrode layer2or the organic light emitting layer3, such as cracking, peeling and so on, and improving reliability performance of the flexible display device.

FIG. 7shows a schematic flow chart of a method for manufacturing a flexible display device before the step of preparing a first cathode electrode portion according to an embodiment of the present application.

As shown inFIG. 7, before preparing the first cathode electrode portion on the surface of the organic light emitting layer, the manufacturing method further includes the following steps.

S001: a second module8includes a first substrate01is provided or manufactured. The first substrate01may be a flexible substrate such as a polyimide (PI) substrate, or may be a rigid substrate such as a glass substrate or the like. In order to facilitate to peel off, an embodiment of the present application may adopt a glass substrate, but a type of the first substrate01is not specifically limited in the embodiments of the present application. In an embodiment, the second module8may further include a backplane02, and the backplane02may be a Thin Film Transistor (TFT) backplane. The TFT backplane has advantages of high responsivity, high contrast, lightness, thinness, low power consumption and the like. However, it should be understood that the specific structural form of the second module8is not limited in the embodiments of the present application.

S002: an anode electrode layer5on the second module8is prepared. Similarly, the anode electrode layer5may be prepared by a vapor deposition method. However, the method for preparing the anode electrode layer is not specifically limited in the embodiments of the present application.

S003: a pixel defining layer4that exposes the anode electrode layer5on the second module8is prepared. During the preparing process, a part of the anode electrode layer5may be exposed, or all of the anode electrode layer5may be exposed such that the anode electrode layer5is surrounded by the pixel defining layer4. However, it should be understood that this is not specifically limited in the embodiments of the present application.

S004: an organic light emitting layer3on the exposed anode electrode layer5is prepared. The organic light emitting layer3may be deposited on the anode electrode layer5by a vapor deposition method. Similarly, the method for preparing the organic light emitting layer3is not specifically limited in the embodiments of the present application.

Through the above-mentioned steps, the organic light emitting layer3may be obtained, and the pixel defining layer4surrounds the organic light emitting layer3. However, it should be understood that the above-mentioned steps are only one embodiment of preparing the organic light emitting layer3, and the specific method for preparing the organic light emitting layer is not limited in the embodiments of the present application.

In an embodiment, before electrically connecting the second cathode electrode202and the first cathode electrode201, the method may further include the following steps.

An adhesive material7on a surface of the pixel defining layer4is prepared.

However, it should be understood that the preparing step may also include preparing the adhesive material7in a region of the first module corresponding to the pixel defining layer4. Or the preparing step include preparing the adhesive material7on the surface of the pixel defining layer4, and preparing the adhesive material7in a region of the first module corresponding to the pixel defining layer4. The position of the adhesive material7prepared in the embodiment of the present application is not specifically limited in the embodiments of the present application. By preparing the adhesive material7, the second cathode electrode202and the first cathode electrode201can be easily electrically connected. The adhesion of the second cathode electrode portion202to the first cathode electrode portion201is improved. In an embodiment, the adhesive material7is a UV adhesive (photosensitive adhesive), and the step may be accomplished by a UV adhesive dispensing process. However, it should be understood that type of the adhesive material7is not limited in the embodiments of the present application.

In an embodiment, a surface of the pixel defining layer4may include a groove41. Therefore, before electrically connecting the second cathode electrode portion202and the first cathode electrode portion201, the manufacturing method may further includes the following steps. The adhesive material7in the groove41on the surface of the pixel defining layer4is prepared; and/or, the adhesive material7in a region of the first module corresponding to the groove41is prepared.

In the embodiment of the present application, at least one adhesive material7can be confined in at least one groove41by opening at least one groove41on the upper surface of the pixel defining layer4, which can facilitate a good contact connection between the first cathode electrode portion201and the second cathode electrode portion202; and avoid poor contact caused by a gap that occurs when the first cathode electrode portion201and the second cathode electrode portion202are electrically connected.

However, it should be understood that the opening at least one groove41on the upper surface of the pixel defining layer4is not a necessary step as long as it can be ensured that the good contact of the electrical connection between the first cathode electrode201and the second cathode electrode202is achieved and the gap that occurs when the two are electrically connected is avoided by using at least one adhesive material7.

In an embodiment, after electrically connecting the second cathode electrode portion202and the first cathode electrode portion201, the manufacturing method further includes the step of peeling off the first substrate01. Because the main function of the first substrate01is supporting, the manufacture of the flexible display device is facilitated. The thickness of the flexible display device can be reduced by peeling off the first substrate01.

FIG. 8is a schematic flow chart of preparing a second cathode electrode portion superposed on a surface of a first module according to an embodiment of the present application.

As shown inFIG. 8, the manufacturing procedure includes the following steps.

S121: a second substrate03is provided or prepared. The second substrate03may be a flexible substrate such as a polyimide (PI) substrate, or may be a rigid substrate such as a glass substrate or the like. In the embodiment of the present application, the second substrate03may adopt a glass substrate in order to facilitate the peeling off, but the type of the second substrate03is not specifically limited in the embodiments of the present application.

S122: an encapsulation layer1on the second substrate03is prepared. The second substrate03may be an organic thin film layer, an inorganic thin film layer, or a superposed structure of an inorganic thin film layer and an organic thin film layer. However, it should be understood that the specific structural form of the encapsulation layer1is not limited in the embodiments of the present application. The encapsulation layer1is mainly used to prevent water vapor and oxygen from immersing into an organic light emitting device and prevent aging of the organic light emitting device, thereby prolonging the life of the organic light emitting device.

S123: a second cathode electrode portion202on the encapsulation layer1is prepared. The preparation of the second cathode electrode202on the encapsulation layer1may be performed by a vapor deposition method, which makes the second cathode electrode202graphical. However, it should be understood that the method for preparing the second cathode electrode portion202is not specifically limited in the embodiments of the present application.

In an embodiment, the second cathode electrode portion202includes at least one second protrusion2020. In an embodiment, a layer thickness of the second cathode electrode portion202may be 20 nm, and a width of the second protrusion2020is in a range from 3 to 20 μm, but the width of the second protrusion2020may be determined according to a size of sub pixel, and the position is disposed corresponding to the first cathode electrode portion201. However, it should be understood that the layer thickness of the second cathode electrode, the width of the second protrusion2020, and the position of the second protrusion2020are not specifically limited in the embodiments of the present application. However, it should be understood that a first protrusion (not shown) may also be prepared on the first cathode electrode portion201, and the first cathode electrode portion201is electrically connected with the second cathode electrode portion202through the first protrusion. However, preparing the first protrusion on the first cathode electrode portion201requires adding a film coating process. Therefore, in the present embodiment, it is preferable to prepare the second protrusion2020on the second cathode electrode202, and the second cathode electrode portion202is electrically connected with the first cathode electrode portion201through the second protrusion2020to form at least one opening structure6. Good electrical connection between the first cathode electrode portion201and the second cathode electrode portion202is facilitated.

In an embodiment, after electrically connecting the second cathode electrode portion to the first cathode electrode portion, the manufacturing method further includes the step of peeling off the second substrate03. Because the main function of the second substrate03is supporting to facilitate the manufacturing of the flexible display device. The thickness of the flexible display device can be reduced by peeling off the second substrate03. After the second substrate03is peeled off, the encapsulation layer1may be exposed. Since the encapsulation layer1may include an organic thin film layer such as a PI layer, a TouchPanel (TP) functional layer may be directly prepared on the surface of the PI layer, which saves a PI layer preparation process comparing with the existing TouchPanel (TP) functional layer preparation technology, and also saves a bonding process. Since there is no bonding process, an Optically Clear Adhesive (OCA) layer can be reduced. Therefore, the overall thickness of the flexible display can be reduced, which is beneficial to improve the overall bending resistance of the flexible display device.

It should be understood that the method set forth in this embodiment is also applicable when the associated groove is replaced with a gap corresponding to the structure of the above embodiment.

Furthermore, it should be also understood that, in the method embodiments of the present application, the steps involved in preparing may be the specific implementations of the corresponding steps involved in providing. For example, the step of preparing a cathode electrode layer may be a specific implementation of the step of providing a cathode electrode layer.

The above-mentioned display devices may be applied to mobile devices, computers, tablets, VR, AR and other terminal devices.

It should be understood that the first and second qualifiers mentioned in the embodiments of the present application is merely for the purpose of more clearly describing the technical solutions of the embodiments of the present application and cannot be used to limit the scope of the present application.

The above are only the preferred embodiments of the present application, and are not intended to limit the scope of the present application. Any modifications, equivalent substitutions, improvements and the like made within the spirit and principles of the present application should be included within the scope of the present application.