CN117320516A - Preparation method of light-emitting substrate, display panel and display device - Google Patents

Abstract

The embodiment of the disclosure provides a preparation method of a light-emitting substrate, a display panel and a display device. The preparation method of the light-emitting substrate comprises the following steps: providing a substrate, wherein one side of the substrate is provided with a plurality of first electrodes arranged in an array manner, the substrate comprises a plurality of pixel areas arranged in an array manner, each pixel area comprises a plurality of sub-areas, and each first electrode is positioned on one sub-area; forming a light emitting device of a target color in each target sub-region in turn for each pixel region on one side of the substrate; wherein the step of forming a light emitting device of a target color in the target sub-region comprises: sequentially forming a light-emitting functional layer, a second electrode and a protective sacrificial layer which cover the first electrode of each sub-region and are connected into a whole and of a target color on one side of the pixel region, which is far away from the substrate, of the first electrode; and removing the light-emitting functional layer, the second electrode and the protective sacrificial layer of the target color on the non-target sub-region by a photoetching process, wherein the non-target sub-region is a region except the target sub-region in the pixel region.

Description

Preparation method of light-emitting substrate, display panel and display device

Technical Field

The disclosure relates to the technical field of display, in particular to a preparation method of a light-emitting substrate, a display panel and a display device.

Background

With the development of display technology, large-size and high PPI (Pixels Per Inch) are important parameter indicators of display devices. In the related art, the pixel pattern that can be formed under the photolithography technique can achieve an accuracy of about 2 μm, that is, a display device of 5000PPI can be formed.

The photoetching process comprises the following steps: gluing, exposing, developing, etching and cleaning. In the cleaning step, since the photoresist itself is an organic substance, it dissolves the organic solvent based on similar compatibility characteristics, so that the remaining portion of the photoresist can be removed by the organic solvent. From the above analysis, it is known that in the process of manufacturing the light emitting device, each film material in the light emitting functional layer is an organic material, and the photoresist removing solvent may damage the light emitting functional layer. In summary, in the process of cleaning PR, the vapor generated by the organic solvent for photoresist stripping may cause vapor erosion to the light-emitting functional layer, thereby affecting the light-emitting effect of the light-emitting device.

Disclosure of Invention

The embodiment of the disclosure provides a preparation method of a light-emitting substrate, a display panel and a display device.

In a first aspect, an embodiment of the present disclosure provides a method for manufacturing a light emitting substrate, including: providing a substrate, wherein one side of the substrate is provided with a plurality of first electrodes arranged in an array manner, the substrate comprises a plurality of pixel areas arranged in an array manner, each pixel area comprises a plurality of sub-areas, and each first electrode is positioned on one sub-area;

forming a light emitting device of a target color in each target subarea in sequence on one side of the substrate for each pixel area, wherein the light emitting device comprises a light emitting functional layer of the target color and a second electrode, and the colors of the light emitting devices corresponding to a plurality of subareas in the same pixel area are different;

wherein the step of forming a light emitting device of a target color in each target sub-region in turn comprises:

sequentially forming a light-emitting functional layer, a second electrode and a protective sacrificial layer of the target color, wherein the light-emitting functional layer covers the first electrode of each sub-region and is connected with the first electrode into a whole, on one side of the pixel region, which is far away from the substrate, of the first electrode; and removing the light-emitting functional layer, the second electrode and the protective sacrificial layer of the target color on a non-target sub-region by a photoetching process, wherein the non-target sub-region is a region except the target sub-region in the pixel region.

In some embodiments, the material of the protective sacrificial layer is acrylic or silicon nitride.

In some embodiments, the step of removing the light emitting functional layer, the second electrode, and the protective sacrificial layer of the target color on the non-target sub-region by a patterning process includes:

forming a shading pattern on one side of the target subarea, which is far away from the substrate, of the protective sacrificial layer;

etching the non-target subarea based on the shading pattern to remove the luminous functional layer, the second electrode and the protective sacrificial layer of the target color on the non-target subarea;

and removing the shading pattern on the target subarea.

In some embodiments, the step of forming a light emitting device of a target color in a target sub-region includes: forming a light emitting device of a target color and the sacrificial protective layer in a target sub-region;

after the light emitting device of the corresponding target color and the sacrificial protective layer are formed on each of the sub-regions in the pixel region, the method further includes:

and carrying out plasma process treatment on the protective sacrificial layer on each subarea in the pixel area, and removing the protective sacrificial layer.

In some embodiments, before the step of sequentially forming the light emitting functional layer of the target color, the second electrode, and the protective sacrificial layer, which cover the first electrode of each of the sub-regions and are integrally connected, the method further includes:

depositing a thin film of pixel defining material on a side of the first electrode remote from the substrate;

patterning the pixel defining material film to form a pixel defining layer, wherein the pixel defining layer comprises a plurality of accommodating holes arranged in an array, and each accommodating hole exposes at least part of the first electrode.

In some embodiments, the step of sequentially forming the first electrode covering each of the sub-regions and integrally forming the light emitting function layer of the target color, the second electrode and the protective sacrificial layer on the side of the pixel region, which is away from the substrate, includes:

sequentially forming a hole injection layer, a hole transport layer, a light emitting layer corresponding to a target color, an electron transport layer and an electron injection layer in a region of the first electrode, which is far away from the substrate and corresponds to the whole pixel region, so as to form the light emitting functional layer;

forming the second electrode on one side of the light-emitting functional layer away from the substrate;

and forming a protective sacrificial layer on one side of the second electrode away from the substrate based on a thin film packaging process.

In some embodiments, the step of performing a plasma process treatment on the protective sacrificial layer on each of the sub-regions in the pixel region, and removing the protective sacrificial layer further comprises:

and depositing a first conductive material film on one side of the pixel area, which is far away from the substrate, to form a first conductive layer, wherein the first conductive layer is configured to electrically connect the second electrode in each sub-area.

In some embodiments, after the step of forming the first conductive layer, the method further comprises:

and an optical adjusting layer and an optical protective layer are formed on one side of the pixel area, which is far away from the substrate, by vapor deposition in sequence.

In some embodiments, after the step of sequentially vapor depositing the optical adjustment layer and the optical protection layer, the method further comprises:

and forming an encapsulation layer on one side of the pixel region, which is far away from the substrate, by a thin film encapsulation process, wherein the surface of one side of the encapsulation layer, which is far away from the substrate, is a flat surface.

In a second aspect, embodiments of the present disclosure provide a display panel including a light-emitting substrate formed using the manufacturing method provided in the first aspect.

In a third aspect, embodiments of the present disclosure provide a display device including the display panel provided in the second aspect.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

fig. 1 is a schematic flow chart of a method for manufacturing a light-emitting substrate according to an embodiment of the disclosure;

fig. 2 is a schematic flowchart of step S2' provided in an embodiment of the disclosure;

fig. 3 is a schematic flowchart of another method for manufacturing a light-emitting substrate according to an embodiment of the disclosure;

fig. 4 is a schematic flowchart of a method for manufacturing a light-emitting substrate according to an embodiment of the disclosure;

FIGS. 5a to 5e are schematic views showing the structure of intermediate products obtained by the preparation method shown in FIG. 4.

Reference numerals illustrate:

wafer substrate 10: a first electrode ITO, a red subarea R, a green subarea G and a blue subarea B;

light-emitting functional layer E: a hole injection layer HIL, a hole transport layer HTL, an electron injection layer ETL, an electron transport layer EIL, a luminescent layer rEML with a red light emission color, a luminescent layer gEML with a green light emission color, and a luminescent layer bEML with a blue light emission color;

a second electrode M, a first conductive layer M', a first conductive material film M1, a second conductive material film M2, a third conductive material film M3, and a fourth conductive material film M4;

an optical adjusting layer CPL and an optical protective layer LiF;

a protective sacrificial layer A, a packaging layer B and a shading pattern pr.

Detailed Description

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. It will be apparent that the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments, which can be made by one of ordinary skill in the art without the need for inventive faculty, are within the scope of the present disclosure, based on the described embodiments of the present disclosure.

Unless defined otherwise, technical or scientific terms used in 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," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

The light-emitting substrate comprises a plurality of pixel units which are arranged in an array manner, each pixel unit comprises sub-pixel units with three colors of red, green and blue, and each sub-pixel unit comprises a light-emitting device with a corresponding color. Taking an OLED display device as an example, the light emitting device in each sub-pixel unit includes an anode layer, a light emitting functional layer and a cathode layer, where the light emitting functional layer includes a hole injection layer, a hole transport layer, a light emitting layer with a light emitting color of red/green/blue, an electron transport layer, and an electron injection layer. It should be understood that the materials of the film layers in the light-emitting functional layer are all organic materials.

In general, a pixel juxtaposition method (Side-by-Side) is used in an OLED display device to manufacture light emitting devices having different emission colors. In the fabrication of each light emitting device, a masking technique may be used. Specifically, the shielding effect of a mask area on a mask plate is utilized to shield the areas corresponding to the sub-pixel units with two colors in the pixel units, then film forming materials are deposited in the sub-pixel units with non-shielded colors in a vapor deposition or ink-jet printing mode, and the formed corresponding patterns are used as main materials of the luminous layers of the luminous devices of the sub-pixel units; and then sequentially forming the light-emitting layers of the light-emitting devices with other two colors by the same preparation steps, thereby preparing the light-emitting layer of the whole pixel unit. Further, an electron transport layer, an electron injection layer, and a cathode layer are formed in the pixel unit integrally to complete the fabrication of all light emitting devices in the pixel unit.

With the development of display technology, large-size and high PPI (Pixels Per Inch) are important parameter indicators of display devices. Meanwhile, further refinement of the pattern region on the Mask for forming the light emitting device is also required, which requires the use of a Fine Metal Mask (FMM).

However, due to the phenomena of mask alignment, mask blockage and the like, the maximum display device formed by adopting the FMM preparation can reach 3000PPI, and at the moment, the light-emitting device in the display device formed by adopting the photoetching technology has greater advantages. It was verified that the pixel pattern that can be formed under the photolithography technique can reach an accuracy of about 2 μm, that is, a display device of 5000PPI can be formed.

Specifically, the photolithography process includes the steps of: gluing, exposing, developing, etching and cleaning. The photoresist coating is to coat Photoresist (PR) on the wafer substrate by using a spin coating method; exposure means that the chemical property of the photoresist at the irradiated part is changed through irradiation of UV light; developing means that the irradiated photoresist reacts under the action of the developing solution to fall off, the material below the photoresist is exposed, the non-irradiated part does not react, and the material below the photoresist is continuously covered; the etching comprises dry etching and wet etching, wherein the dry etching is to remove the part of the material by reacting plasma gas with the material below; the cleaning refers to cleaning and removing the PR which is not irradiated under the action of an organic solvent, thereby forming a pattern.

In the above-described cleaning step, since the photoresist itself is an organic substance, it is dissolved in an organic solvent based on similar compatibility characteristics, and thus the remaining portion of the photoresist can be removed under the action of the organic solvent. From the above analysis, it is known that the materials of each film layer in the light-emitting functional layer are organic materials in the process of manufacturing the light-emitting device, and thus the photoresist remover may damage the light-emitting functional layer. In summary, in the process of cleaning PR, the vapor generated by the organic solvent for photoresist stripping may cause vapor erosion to the light-emitting functional layer, thereby affecting the light-emitting effect of the light-emitting device.

In order to solve at least one or more of the above technical problems, an embodiment of the present disclosure provides a light emitting substrate, which protects a light emitting device by a protection sacrificial layer, avoids adverse effects such as vapor erosion on the light emitting device, and ensures a light emitting effect of the light emitting substrate.

Fig. 1 is a schematic flowchart of a method for manufacturing a light-emitting substrate according to an embodiment of the disclosure, where, as shown in fig. 1, the method for manufacturing a light-emitting substrate includes:

step S1, a substrate is provided, one side of the substrate is provided with a plurality of first electrodes arranged in an array mode, the substrate comprises a plurality of pixel areas arranged in an array mode, each pixel area comprises a plurality of sub-areas, and each first electrode is located on one sub-area.

It should be understood that the light emitting device in the light emitting substrate in the present disclosure is formed based on a photolithography process, and the basic principle of the photolithography process is to etch the pattern on the mask plate onto the processed surface by utilizing the feature that the photoresist (or photoresist) is photo-induced and then forms corrosion resistance due to photochemical reaction. In order to increase the adhesion between the photoresist and the substrate, the substrate is preferably a wafer substrate.

In addition, when using a wafer substrate, it is first necessary to pretreat the substrate, for example, to coat the surface of the cleaned substrate with an adhesion enhancer or to heat treat the substrate in an inert gas before coating a photoresist. The treatment is to increase the adhesion between the photoresist and the substrate, prevent the photoresist pattern from falling off during development and prevent the side corrosion during wet etching.

Step S2, on one side of the substrate, performing step S2' for each pixel region: and forming a light emitting device with a target color in each target subarea in sequence, wherein the light emitting device comprises a light emitting functional layer with the target color and a second electrode, and the colors of the light emitting devices corresponding to a plurality of subareas in the same pixel area are different.

Wherein the step S2' of forming a light emitting device of a target color in each target sub-region of the pixel region includes:

step S21, forming a luminous functional layer, a second electrode and a protective sacrificial layer which cover the first electrode of each sub-region and are connected into a whole and are of a target color in the pixel region and are positioned on one side of the first electrode far away from the substrate; step S22, removing the light-emitting functional layer, the second electrode and the protective sacrificial layer of the target color on the non-target sub-region by a photoetching process, wherein the non-target sub-region is a region except the target sub-region in the pixel region.

According to the preparation method of the light-emitting substrate, after the first electrode, the light-emitting functional layer and the second electrode of the light-emitting device are sequentially formed on the substrate, the protective sacrificial layer is formed above the second electrode, and when the film layer structure on the non-target subarea is removed through the photoetching process, the influence of development and etching on the light-emitting functional layer in the patterning process can be isolated under the action of the protective sacrificial layer. And the protective sacrificial layer covers the first electrode, the light-emitting functional layer and the second electrode of the light-emitting device, that is, in the process of sequentially preparing each light-emitting device in the pixel region, the whole structure of each light-emitting device is independently formed under the coverage of the protective sacrificial layer, so that crosstalk can not be generated between the light-emitting devices, and the light-emitting effect of the light-emitting substrate can be improved.

It should also be noted that, in one example, the pixel region includes three sub-regions, which are a red sub-region including a red light emitting device, a green sub-region including a green light emitting device, and a blue sub-region including a blue light emitting device, respectively. The pixel region further includes a plurality of spacers, the spacers are regions between any two sub-regions, and when the red light emitting device is manufactured, the red sub-region is a target sub-region, and at this time, the non-target sub-region includes not only the green sub-region and the blue sub-region, but also a plurality of spacers, for example, a spacer between the red sub-region and the green sub-region, and a spacer between the green sub-region and the blue sub-region.

In some embodiments, the material of the protective sacrificial layer is acrylic or silicon nitride. Specifically, an acrylic acid or silicon nitride material is formed on a side of the second electrode away from the substrate by a thin film encapsulation (Thin Film Encapsulation, TFE) process, and a protective sacrificial layer is formed by the TFE process, thereby blocking moisture or air causing insufficient brightness and occurrence of fatal defects such as black spots of the light emitting device, so as to ensure the light emitting effect of the light emitting device.

Fig. 2 is a schematic flowchart of step S2 'provided in the embodiment of the disclosure, and in some embodiments, as shown in fig. 2, before step S21, step S2' further includes step S20: depositing a thin film of pixel defining material on a side of the first electrode remote from the substrate; patterning the pixel defining material film to form a pixel defining layer, wherein the pixel defining layer comprises a plurality of accommodating holes arranged in an array, and each accommodating hole exposes at least part of the first electrode.

The pixel defining layer may be made of a polymer material that can block water vapor, for example, an acrylic material, so as to block water molecules and/or oxygen molecules that invade the interior.

In addition, the receiving hole formed in the pixel defining layer has a trapezoid shape in the thickness direction of the light emitting substrate, and the trapezoid shape having isotropic characteristics generated when the pixel defining layer is prepared can prevent intrusion of impurities in the environment, thereby protecting the light emitting device.

In some embodiments, the step S22 may specifically include:

step S220, forming a shading pattern on one side of the target subarea, which is far away from the substrate, of the protective sacrificial layer; etching the non-target subarea based on the shading pattern to remove the luminous functional layer, the second electrode and the protective sacrificial layer of the target color on the non-target subarea; and removing the shading pattern on the target subarea.

Specifically, the material of the light shielding pattern may be photoresist PR, in one example, firstly, a PR covering the whole pixel area is coated above the sacrificial protection layer, a mask is coated above the photoresist, a UV lamp is irradiated on the PR on the non-target sub-area based on the mask pattern, and the PR on the non-target sub-area is removed by developing to expose the protective sacrificial layer on the non-target sub-area; further, the protective sacrificial layer, the second electrode and the luminous functional layer with the target color on the non-target subarea are sequentially etched and removed, and at the moment, each film layer on the target subarea is not affected by etching under the action of PR, so that each structure of the target subarea is reserved; further, PR on the target subregion is removed under the action of the organic solvent, and at this time, the protective sacrificial layer on the target subregion covers the light emitting device, so that water vapor generated by the organic solvent for removing PR does not affect the light emitting functional layer in the light emitting device.

Fig. 3 is a schematic flowchart of another method for manufacturing a light emitting substrate according to an embodiment of the disclosure, in some embodiments, after a light emitting device and a sacrificial protection layer corresponding to a target color are formed on each sub-region of a pixel region as shown in fig. 3, the method further includes step S3: and carrying out plasma process treatment on the protective sacrificial layer on each sub-area in the pixel area, and removing the protective sacrificial layer.

In one example, when the light emitting device corresponding to the light emitting color is formed in each sub-area of the pixel area in turn according to the method provided in the above step S2', although the protection sacrificial layer on each target sub-area can protect the light emitting device covered by the protection sacrificial layer, the second electrode and the light emitting functional layer, when the photolithography process is performed on the protection sacrificial layer, the second electrode and the light emitting functional layer in the non-target sub-area, a large amount of particles (particles) are generated in the protection sacrificial layer remained on the target sub-area, thereby causing dark point defects on the pixel area. Based on this, the protective sacrificial layer deposited in each sub-region is removed by a plasma dry etching (plamsa) process, whereby dark spot defects on the pixel region due to particle can be eliminated.

In some embodiments, as shown in fig. 2, the step S21 may specifically include:

step S210, sequentially forming a hole injection layer, a hole transport layer, a light emitting layer corresponding to a target color, an electron transport layer and an electron injection layer in a region of the first electrode, which is far away from the substrate and corresponds to the whole pixel region, so as to form a light emitting functional layer; forming a second electrode on one side of the light-emitting functional layer away from the substrate; and forming a protective sacrificial layer on one side of the second electrode away from the substrate based on a thin film packaging process.

It should be understood that when a current is passed inside the light emitting device, holes are generated from the first electrode and electrons are generated from the second electrode, wherein the holes are injected into the light emitting layer through the hole injection layer and the hole transport layer, the electrons are injected into the light emitting layer through the electron injection layer and the electron transport layer, and excitons are formed in the light emitting layer to emit light.

In the embodiment of the disclosure, the light emitting devices in each sub-region in the pixel region are sequentially prepared and formed in the accommodating portion corresponding to the pixel defining region, that is, each film structure in the light emitting functional layer corresponding to each light emitting device is independently formed, and each film structure included in the light emitting functional layer in different light emitting devices is not shared, so that the risk of pixel crosstalk in different sub-regions is reduced, and the light emitting effect of the light emitting substrate is improved.

The first electrode may be a transparent electrode made of an indium tin oxide material, and the second electrode may be a reflective electrode made of a metal material.

In some embodiments, as shown in fig. 3, after step S3, the method further includes step S4: and depositing a first conductive material film on one side of the pixel area, which is far away from the substrate, of the second electrode to form a first conductive layer, wherein the first conductive layer is configured to electrically connect the second electrode in each sub-area.

As can be seen from the above analysis, the second electrodes formed in step S22 are arranged at intervals corresponding to each sub-region, and there is no electrical connection between two second electrodes in adjacent sub-regions. Therefore, after the protective sacrificial layer is removed by the plamsa process, the first conductive layer connected as a whole is formed, and the second electrode independently formed in each sub-region and the first conductive layer stacked above the second electrode form a conductive structure connected as a whole, so that each sub-region uniformly receives a voltage signal in a display stage and provides a pixel voltage for each light emitting device.

In addition, in the step S4, the first conductive layer connected integrally is directly formed on the side of the second electrode away from the substrate, instead of only forming the region between adjacent sub-regions to connect adjacent second electrodes, so that patterning is not required, and the preparation process is saved.

In some embodiments, as shown in fig. 3, the method for preparing a light-emitting substrate further includes step S5: and in the pixel area, the first conducting layer is positioned on one side far away from the substrate, and an optical adjusting layer and an optical protective layer are formed by vapor deposition in sequence.

The optical adjusting layer has a higher refractive index to adjust light emission and form a resonant microcavity, so that the color of the emitted light is improved, for example, the refractive index of the optical adjusting layer to light with 460nm wavelength is greater than 1.8, thereby increasing the emergent angle of light and improving the light emission quantity of the light emitting device. The optical protection layer above the optical adjustment layer can be made of lithium fluoride (LiF) material, so that on one hand, the optical protection layer can be used as a high-refraction material to improve the light extraction efficiency, and on the other hand, the LiF material has a certain UV protection effect, and the influence of UV irradiation on the light-emitting device in the subsequent process can be reduced.

In the above structure, the optical adjustment layer is located between the optical protection layer and the second electrode, so that the optical adjustment layer is equivalent to inserting a medium with a relative refractive index close to a middle value between two mediums with a relatively large difference in refractive index, so as to increase the critical angle, thereby increasing the incident angle of each layer of medium and enabling the light which cannot be taken out originally to be refracted out.

In some embodiments, as shown in fig. 3, the method for preparing a light-emitting substrate further includes step S6: and forming a packaging layer in the pixel area and at one side of the optical protection layer far away from the substrate through a thin film packaging process, wherein the surface of one side of the packaging layer far away from the substrate is a flat surface.

It should be noted that, in the embodiment of the present disclosure, the encapsulation layer and the protection sacrificial layer are formed by using the same material and process, i.e., the encapsulation layer material includes acrylic or silicon nitride. However, after the encapsulation layer is formed by the TFE process, processes such as exposure and dry etching are not required to remove the encapsulation material on a part of the area, so that the phenomenon of particle does not occur. On one hand, the packaging layer formed by the acrylic acid or the silicon nitride can prevent water vapor from entering the light-emitting device, and on the other hand, the surface of the packaging layer, which is far away from the substrate, is a flat surface, so that the preparation of a subsequent structure is facilitated.

The following describes a method for manufacturing a light-emitting substrate in the present disclosure in detail with reference to the accompanying drawings. Fig. 4 is a schematic flow chart of a preparation method of a light-emitting substrate according to an embodiment of the disclosure, and fig. 5a to 5e are schematic structural diagrams of intermediate products prepared by adopting the preparation method shown in fig. 4, so as to prepare and form the light-emitting substrate. It should be noted that, fig. 5a to 5e each show a structure on only one pixel region of the light emitting substrate, and the pixel region includes three sub-regions, namely, a red sub-region R including a red light emitting device, a green sub-region G including a green light emitting device, and a blue sub-region B including a blue light emitting device.

As shown in fig. 4, the preparation method of the light emitting substrate includes steps S01 to S05, which are specifically as follows.

Referring to fig. 5a, step S01 includes steps S101-S103, wherein:

in step S101, a wafer substrate 10 is provided, and a first electrode ITO is formed on a region corresponding to each sub-region on one side of the wafer substrate 10.

The light emitting device in the light emitting substrate in the present disclosure is formed based on a photolithography process, and the basic principle of the photolithography process is to etch a pattern on a mask plate onto a processed surface by utilizing the characteristic that a photoresist (or photoresist) is exposed to light and then forms corrosion resistance due to photochemical reaction, so that the wafer substrate 10 is preferably used as a substrate of the light emitting device.

In step S102, a thin film of acrylic material pdl0 is deposited on the side of the first electrode ITO remote from the wafer substrate 10.

In step S103, patterning the acrylic material film pdl0 by photolithography to form a pixel defining layer, where the pixel defining layer includes a plurality of accommodating holes k arranged in an array, and each accommodating hole k exposes at least a portion of the first electrode ITO.

Referring to fig. 5b, step S02 is for preparing a red light emitting device, and specifically includes steps S201 to S205, wherein:

in step S201, a hole injection layer HIL, a hole transport layer HTL, a light emitting layer reeml with red color, an electron transport layer EIL, and an electron injection layer ETL are sequentially deposited on the pixel region.

In the above steps, each film layer is an organic material layer to form an organic light-emitting functional layer E.

In step S202, a second conductive material film m2 is deposited on the electron injection layer ETL.

In step S203, an acrylic material or a silicon oxide material is deposited on the second conductive material film m2 by a TFE process to form a protective sacrificial layer a.

In step S204, after the PR material is coated on the protective sacrificial layer a, the portion on the region other than the red sub-region R is removed after exposure and development, and only the PR on the red sub-region R remains to form the light shielding pattern PR.

In step S205, the hole injection layer HIL, the hole transport layer HTL, the light emitting layer reeml with red color, the electron transport layer EIL, the electron injection layer ETL, and the second conductive material film m2 are removed from the region outside the red sub-region R by a dry etching process, and the light shielding pattern pr on the red sub-region R is cleaned.

At this time, a red light emitting device is formed on the red sub-region R, and only the second conductive material film M2 remaining on the red sub-region R serves as the second electrode M of the red light emitting device.

When the red light-emitting device is formed, each film layer on the red subarea R is not affected by etching under the action of PR, so that each structure of the red subarea R is reserved; further, PR on the red sub-region R is removed by the organic solvent, and at this time, the protective sacrificial layer a on the red sub-region R covers the light emitting device, so that moisture generated by the organic solvent for removing PR does not affect the light emitting functional layer E in the light emitting device.

Further, based on the same inventive concept as that of the red light emitting device in the red sub-region R, a green light emitting device in the green sub-region G and a blue light emitting device in the blue sub-region B are prepared.

Referring to fig. 5c, step S03 is for preparing a green light emitting device, and specifically includes steps S301 to S305, wherein:

in step S301, a hole injection layer HIL, a hole transport layer HTL, a light emitting layer g with green color, an electron transport layer EIL, and an electron injection layer ETL are sequentially deposited on the pixel region.

In step S302, a third conductive material film m3 is deposited on the electron injection layer ETL.

In step S303, an acrylic material or a silicon oxide material is deposited on the third conductive material thin film m3 by a TFE process to form a protective sacrificial layer a.

In step S304, PR material is coated on the protective sacrificial layer a, and after exposure and development, a portion on the region other than the green sub-region G is removed, and only PR on the green sub-region G remains to form a light shielding pattern PR.

In step S305, the hole injection layer HIL, the hole transport layer HTL, the light emitting layer gEML with green color, the electron transport layer EIL, the electron injection layer ETL, and the third conductive material film m3 on the area outside the green sub-area G are removed by a dry etching process, and the light shielding pattern pr on the green sub-area G is cleaned. At this time, a green light emitting device is formed on the green sub-region G, and only the third conductive material film M3 remaining on the green sub-region G serves as the second electrode M of the green light emitting device.

Referring to fig. 5d, step S04 is for preparing a blue light emitting device, and specifically includes steps S401 to S405, wherein:

in step S401, a hole injection layer HIL, a hole transport layer HTL, a blue light emitting layer bmml, an electron transport layer EIL, and an electron injection layer ETL are sequentially deposited on the pixel region.

In step S402, a fourth conductive material film m4 is deposited on the electron injection layer ETL.

In step S403, an acrylic material or a silicon oxide material is deposited on the fourth conductive material film m4 by a TFE process to form a protective sacrificial layer a.

In step S404, after the PR material is coated on the protective sacrificial layer a, the portion on the area other than the blue sub-area B is removed after exposure and development, and only the PR on the blue sub-area B remains to form the light shielding pattern PR.

In step S405, the hole injection layer HIL, the hole transport layer HTL, the light emitting layer B with blue emission color, the electron transport layer EIL, the electron injection layer ETL, and the fourth conductive material film m4 on the area outside the blue sub-area B are removed by a dry etching process, and the light shielding pattern pr on the blue sub-area B is cleaned. At this time, a blue light emitting device is formed on the blue sub-region B, and only the fourth conductive material film M4 remaining on the blue sub-region B serves as the second electrode M of the blue light emitting device.

Referring to fig. 5e, step S05 comprises step S501-step S504, wherein:

in step S501, the protective sacrificial layer a in each sub-region is removed by a plasma process.

Although the protective sacrificial layer a on each target subregion can protect the light emitting device covered therewith, when the photolithography process is performed on the protective sacrificial layer a, the second electrode M, and the light emitting functional layer E on the non-target subregion, a large amount of particles (particles) are generated in the protective sacrificial layer a remaining on the target subregion, thereby causing dark point defects on the pixel region. Based on this, the protective sacrificial layer a deposited in each sub-region is removed by a plasma dry etching (plamsa) process, whereby dark spot defects on the pixel region due to particle can be eliminated.

In step S502, a first conductive material film M1 is deposited to form a first electrode layer M'.

In step S503, the optical adjustment layer CPL and the optical protection layer LiF are sequentially formed on the first electrode layer M'.

The optical adjusting layer CPL is used for increasing the outgoing angle of the light and improving the outgoing light quantity of the light emitting device. The optical protection layer LiF above the optical adjustment layer CPL can be made of lithium fluoride (LiF) material, on one hand, the optical protection layer LiF can be used as a high-refraction material to improve the light extraction efficiency, on the other hand, the LiF has a certain degree of UV protection effect, and the influence of UV irradiation on the light emitting device in the subsequent process can be reduced.

In step S504, acrylic or silicon oxide is deposited on the optical protection layer LiF by TFE process to form an encapsulation layer B.

In the method for manufacturing the light-emitting substrate provided by the embodiment of the disclosure, after the first electrode ITO, the light-emitting functional layer E and the second electrode M of the light-emitting device are sequentially formed on the substrate, the protective sacrificial layer a is formed above the second electrode M, so that when the film layer structure on the non-target sub-region is removed through the photolithography process, the effect of development and etching on the light-emitting functional layer E in the patterning process can be isolated under the action of the protective sacrificial layer a. And the protective sacrificial layer A covers the first electrode ITO, the luminous functional layer E and the second electrode M of the luminous device, namely, in the process of sequentially preparing each luminous device in the pixel region, the whole structure of each luminous device is independently formed under the coverage of the protective sacrificial layer A, so that the luminous devices are protected from generating crosstalk, and the luminous effect of the luminous substrate is improved.

In addition, it should be noted that the material thickness of all the film layers can be flexibly adjusted by those skilled in the art, which is not limited in the embodiments of the present disclosure.

Based on the same inventive concept, the embodiments of the present disclosure further provide a display panel, including the light-emitting substrate prepared by the preparation method provided in any one of the embodiments.

The embodiment of the disclosure also provides a display device comprising the display panel.

The display device may be: any product or component with a display function, such as electronic paper, mobile phone, tablet computer, television, display, notebook computer, digital photo frame, navigator, etc., which is not limited in this disclosure.

It is to be understood that the above embodiments are merely exemplary embodiments employed to illustrate the principles of the present disclosure, however, the present disclosure is not limited thereto. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the disclosure, and are also considered to be within the scope of the disclosure.

Claims (11)

1. A method of manufacturing a light emitting substrate, the method comprising:

providing a substrate, wherein one side of the substrate is provided with a plurality of first electrodes arranged in an array manner, the substrate comprises a plurality of pixel areas arranged in an array manner, each pixel area comprises a plurality of sub-areas, and each first electrode is positioned on one sub-area;

forming a light emitting device of a target color in each target subarea in sequence on one side of the substrate for each pixel area, wherein the light emitting device comprises a light emitting functional layer of the target color and a second electrode, and the colors of the light emitting devices corresponding to a plurality of subareas in the same pixel area are different;

wherein the step of forming the light emitting device of the target color in each target subregion in turn comprises:

sequentially forming a light-emitting functional layer, a second electrode and a protective sacrificial layer of the target color, wherein the light-emitting functional layer covers the first electrode of each sub-region and is connected with the first electrode into a whole, on one side of the pixel region, which is far away from the substrate, of the first electrode; and removing the light-emitting functional layer, the second electrode and the protective sacrificial layer of the target color on a non-target sub-region by a photoetching process, wherein the non-target sub-region is a region except the target sub-region in the pixel region.

2. The method of manufacturing a light-emitting substrate according to claim 1, wherein the material of the protective sacrificial layer is acrylic or silicon nitride.

3. The method of manufacturing a light-emitting substrate according to claim 1, wherein the step of removing the light-emitting functional layer, the second electrode, and the protective sacrificial layer of the target color on the non-target sub-region by patterning, comprises:

forming a shading pattern on one side of the target subarea, which is far away from the substrate, of the protective sacrificial layer;

etching the non-target subarea based on the shading pattern to remove the luminous functional layer, the second electrode and the protective sacrificial layer of the target color on the non-target subarea;

and removing the shading pattern on the target subarea.

4. The method of manufacturing a light-emitting substrate according to claim 1, wherein the step of forming a light-emitting device of a target color in the target sub-region comprises: forming a light emitting device of a target color and the sacrificial protective layer in a target sub-region;

after the light emitting device of the corresponding target color and the sacrificial protective layer are formed on each of the sub-regions in the pixel region, the method further includes:

and carrying out plasma process treatment on the protective sacrificial layer on each subarea in the pixel area, and removing the protective sacrificial layer.

5. The method of manufacturing a light-emitting substrate according to claim 1, wherein before the step of sequentially forming the light-emitting functional layer of the target color, the second electrode, and the protective sacrificial layer, which cover the first electrode of each of the sub-regions and are integrally connected, the method further comprises:

depositing a thin film of pixel defining material on a side of the first electrode remote from the substrate;

patterning the pixel defining material film to form a pixel defining layer, wherein the pixel defining layer comprises a plurality of accommodating holes arranged in an array, and each accommodating hole exposes at least part of the first electrode.

6. The method of manufacturing a light-emitting substrate according to claim 1, wherein the step of sequentially forming the light-emitting functional layer of the target color, the second electrode, and the protective sacrificial layer, which cover the first electrode of each of the sub-regions and are integrally connected, in the pixel region, at a side of the first electrode away from the substrate, comprises:

sequentially forming a hole injection layer, a hole transport layer, a light emitting layer corresponding to a target color, an electron transport layer and an electron injection layer in a region of the first electrode, which is far away from the substrate and corresponds to the whole pixel region, so as to form the light emitting functional layer;

forming the second electrode on one side of the light-emitting functional layer away from the substrate;

and forming a protective sacrificial layer on one side of the second electrode away from the substrate based on a thin film packaging process.

7. The method of manufacturing a light-emitting substrate according to claim 4, wherein after the step of performing a plasma process treatment on the protective sacrificial layer on each of the sub-regions in the pixel region and removing the protective sacrificial layer, the method further comprises:

and depositing a first conductive material film on one side of the pixel area, which is far away from the substrate, to form a first conductive layer, wherein the first conductive layer is configured to electrically connect the second electrode in each sub-area.

8. The method of manufacturing a light-emitting substrate according to claim 7, wherein after the step of forming the first conductive layer, the method further comprises:

and an optical adjusting layer and an optical protective layer are formed on one side of the pixel area, which is far away from the substrate, by vapor deposition in sequence.

9. The method of manufacturing a light-emitting substrate according to claim 8, wherein after the step of sequentially vapor-depositing the optical adjustment layer and the optical protection layer, the method further comprises:

and forming an encapsulation layer on one side of the pixel region, which is far away from the substrate, by a thin film encapsulation process, wherein the surface of one side of the encapsulation layer, which is far away from the substrate, is a flat surface.

10. A display panel comprising a light-emitting substrate formed by the method of any one of claims 1-9.

11. A display device comprising the display panel of claim 10.