Display substrate, preparation method thereof and display device

Abstract

The invention discloses a display substrate, a preparation method thereof and a display device, the display substrate comprises at least one sub-pixel, the at least one sub-pixel comprises a light-emitting device arranged on a substrate, and the light-emitting device comprises a first electrode, a light-emitting function layer and a second electrode which are sequentially stacked in the direction away from the substrate; the light-emitting functional layer comprises at least one light-emitting laminated layer, and the light-emitting laminated layer comprises a light-emitting layer; the first electrode comprises a reflection conducting layer, the reflection conducting layer is configured to reflect at least part of visible light, the reflection conducting layer comprises at least one concave area and a flat area, and the flat area is located on the periphery of the at least one concave area; the orthographic projection of the at least one recessed area on the substrate is overlapped with the orthographic projection of at least part of the light-emitting layer on the substrate.

Description

Technical Field

[0001] This article relates to but is not limited to the field of display technology, and specifically to a display substrate and a preparation method thereof, and a display device. Background Art

[0002] Micro Organic Light-Emitting Diode (Micro-OLED) is a micro display that has been developed in recent years, and silicon-based OLED is one of them. Silicon-based OLED can not only realize active addressing of pixels, but also realize the preparation of pixel driving circuits and other structures on silicon-based substrates, which is conducive to reducing the system volume and achieving lightweight. Silicon-based OLED is prepared using mature complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) integrated circuit technology. It has the advantages of small size, high resolution (Pixels Per Inch, PPI), high refresh rate, etc., and is widely used in virtual reality (VR) or augmented reality (AR) near-eye display fields.

[0003] A tandem organic light-emitting diode (tandem OLED) device is a device structure in which multiple light-emitting stacks are stacked in series. This structure connects multiple light-emitting stacks in series so that each light-emitting stack can emit light separately, thereby improving the efficiency and life of the device. In a tandem organic light-emitting diode (tandem OLED) device, each light-emitting stack contains an emission layer (EML), and current passes through each light-emitting stack in turn, and the light-emitting layer of each light-emitting stack emits light under the action of an electric field. Since the energy level of each light-emitting stack can be designed independently, the performance of each light-emitting layer can be optimized.

[0004] A 2-period tandem organic light-emitting diode (tandem OLED) device includes two light-emitting layers stacked in series, and a 3-period tandem organic light-emitting diode (tandem OLED) device includes three light-emitting layers stacked in series. Therefore, the 2-period and 3-period tandem organic light-emitting diode (tandem OLED) devices have the advantages of stronger microcavity effect, weaker surface plasmon resonance effect (SPP effect), narrower emission spectrum and higher front light extraction efficiency. Summary of the invention

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] On the one hand, the present disclosure provides a display substrate, comprising at least one sub-pixel, wherein the at least one sub-pixel comprises a light-emitting device arranged on a substrate, wherein the light-emitting device comprises a first electrode, a light-emitting functional layer and a second electrode which are sequentially stacked in a direction away from the substrate; the light-emitting functional layer comprises at least one light-emitting stack, and the light-emitting stack comprises a light-emitting layer; the first electrode comprises a reflective conductive layer, wherein the reflective conductive layer is configured to reflect at least part of visible light, and the reflective conductive layer comprises at least one recessed area and a flat area, wherein the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

[0007] In an exemplary embodiment, the thickness of the flat region is greater than the thickness of the recessed region, and a surface of the recessed region away from the substrate is recessed toward the substrate in comparison with a surface of the flat region away from the substrate.

[0008] In an exemplary embodiment, a vertical distance between the at least one recessed region away from the surface of the substrate and the flat region away from the surface of the substrate is greater than or equal to 30 nanometers and less than or equal to 100 nanometers.

[0009] In an exemplary embodiment, the at least one sub-pixel includes a first sub-pixel emitting a first color light, a second sub-pixel emitting a second color light, and a third sub-pixel emitting a third color light, and a vertical distance between at least one recessed area in the first sub-pixel away from the substrate side surface and the flat area away from the substrate side surface, a vertical distance between at least one recessed area in the second sub-pixel away from the substrate side surface and the flat area away from the substrate side surface, and a vertical distance between at least one recessed area in the third sub-pixel away from the substrate side surface and the flat area away from the substrate side surface are approximately equal; or, at least two of the vertical distance between at least one recessed area in the first sub-pixel away from the substrate side surface and the flat area away from the substrate side surface, the vertical distance between at least one recessed area in the second sub-pixel away from the substrate side surface and the flat area away from the substrate side surface, and the vertical distance between at least one recessed area in the third sub-pixel away from the substrate side surface and the flat area away from the substrate side surface are different from each other.

[0010] In an exemplary embodiment, the thickness of the planar region is greater than or equal to 80 nanometers and less than or equal to 120 nanometers.

[0011] In an exemplary embodiment, a shape of the at least one recessed area includes at least one of a circle, an ellipse, a triangle, a rectangle, a diamond, a trapezoid, a pentagon, and a hexagon.

[0012] In an exemplary embodiment, the first electrode further includes a light-transmitting structure layer, at least a portion of which is disposed in the at least one recessed region.

[0013] In an exemplary embodiment, the at least one recessed region includes a bottom wall and a side wall, and the light-transmitting structure layer is in contact with the bottom wall and the side wall.

[0014] In an exemplary embodiment, a surface of the light-transmitting structure layer away from the substrate is substantially flush with a surface of the planar region away from the substrate.

[0015] In an exemplary embodiment, the light-transmitting structural layer includes a light-transmitting layer.

[0016] In an exemplary embodiment, the light-transmitting structural layer includes at least two light-transmitting layers, which are sequentially arranged in a direction away from the substrate, and the refractive indices of the at least two light-transmitting layers sequentially decrease in a direction away from the substrate.

[0017] In an exemplary embodiment, the light-transmitting structure layer includes a first light-transmitting layer and a second light-transmitting layer arranged in sequence along a direction away from the substrate, the refractive index of the first light-transmitting layer is greater than the refractive index of the second light-transmitting layer, the refractive index of the first light-transmitting layer is greater than or equal to 1.8 and less than or equal to 2.5, and the refractive index of the second light-transmitting layer is greater than or equal to 1.5 and less than or equal to 2.2.

[0018] In an exemplary embodiment, the light transmittance of the light-transmitting structural layer to visible light is greater than or equal to 95%.

[0019] In an exemplary embodiment, the light-transmitting structure layer includes at least one of silicon nitride, silicon oxynitride, indium tin oxide, and indium zinc oxide.

[0020] In an exemplary embodiment, the first electrode further includes a first light-transmitting conductive layer and a second light-transmitting conductive layer, the first light-transmitting conductive layer being disposed on a side of the reflective conductive layer close to the substrate, a surface of the first light-transmitting conductive layer away from the substrate being in contact with a surface of the reflective conductive layer close to the substrate, and the second light-transmitting conductive layer being disposed on a side of the reflective conductive layer away from the substrate, a surface of the second light-transmitting conductive layer close to the substrate being in contact with a surface of a flat region of the reflective conductive layer away from the substrate.

[0021] In an exemplary embodiment, the thickness of the first light-transmitting conductive layer is greater than or equal to 5 nanometers and less than or equal to 15 nanometers; the thickness of the second light-transmitting conductive layer is greater than or equal to 5 nanometers and less than or equal to 15 nanometers.

[0022] In an exemplary embodiment, the reflectivity of the reflective conductive layer to visible light is greater than or equal to 90%.

[0023] In an exemplary embodiment, a pixel definition layer is further included, wherein the pixel definition layer is disposed on a side of the first electrode away from the substrate, a pixel opening is disposed in the pixel definition layer, the pixel opening exposes at least a portion of the first electrode, and an orthographic projection of the pixel opening on the substrate overlaps at least a portion of an orthographic projection of the at least one recessed area on the substrate.

[0024] On the other hand, the present disclosure also provides a method for preparing a display substrate, comprising: At least one sub-pixel is formed, the at least one sub-pixel includes a light-emitting device, the light-emitting device includes a first electrode, a light-emitting functional layer and a second electrode which are sequentially stacked in a direction away from the substrate; the light-emitting functional layer includes at least one light-emitting stack, the light-emitting stack includes a light-emitting layer; the first electrode includes a reflective conductive layer, the reflective conductive layer is configured to reflect at least part of the visible light, the reflective conductive layer includes at least one recessed area and a flat area, the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

[0025] On the other hand, the present disclosure further provides a display device, comprising any of the display substrates described above.

[0026] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure.

[0028] Figure 1a is a schematic structural diagram of a related series organic light emitting diode device; Figure 1b is a schematic structural diagram of another related series-connected organic light-emitting diode device; Figure 1c A graph showing the transmittance of light of different wavelengths of the substrate; Figure 2 is a structural schematic diagram of a display device; Figure 3 A schematic diagram of the planar structure of a display area in a display device; Figure 4 is a schematic diagram of a cross-sectional structure of a display area of ​​a display device; Figure 5 This is a schematic diagram of a planar structure of a first electrode of a display substrate according to an embodiment of the present disclosure; Figure 6 It is a schematic cross-sectional structure diagram of a first electrode of a display substrate according to an embodiment of the present disclosure; Figure 7 A schematic cross-sectional structure diagram of a light-emitting device of a display substrate according to an embodiment of the present disclosure; Figure 8 It is a schematic cross-sectional structure diagram of a first electrode of another display substrate according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail in conjunction with the accompanying drawings below. Note that the embodiments can be implemented in multiple different forms. A person of ordinary skill in the art can easily understand the fact that the methods and contents can be transformed into various forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other.

[0030] The proportions of the drawings in this disclosure can be used as a reference in actual processes, but are not limited to this. For example, the width-to-length ratio of the channel, the thickness and spacing of each film layer, and the width and spacing of each signal line can be adjusted according to actual needs. The number of pixels in the display device and the number of sub-pixels in each pixel are not limited to the numbers shown in the figures. The drawings described in this disclosure are only schematic diagrams of the structure. One method of this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0031] In the present specification, ordinal numbers such as “first”, “second” and “third” are provided to avoid confusion among constituent elements, and are not intended to limit the number.

[0032] In this specification, for the sake of convenience, the words and phrases indicating the orientation or positional relationship, such as "middle", "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., are used to illustrate the positional relationship of the constituent elements with reference to the drawings. This is only for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the direction in which each constituent element is described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the situation.

[0033] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0034] In this specification, a transistor refers to an element including at least three terminals: a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain electrode) and a source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, the channel region refers to a region through which current mainly flows.

[0035] In this specification, the first electrode may be a drain electrode and the second electrode may be a source electrode, or the first electrode may be a source electrode and the second electrode may be a drain electrode. In the case of using transistors with opposite polarities or when the current direction changes during circuit operation, the functions of the "source electrode" and the "drain electrode" are sometimes interchanged. Therefore, in this specification, the "source electrode" and the "drain electrode" may be interchanged, and the "source terminal" and the "drain terminal" may be interchanged.

[0036] In this specification, "electrical connection" includes the case where components are connected together through an element having some electrical function. There is no particular limitation on the "element having some electrical function" as long as it can transmit and receive electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions.

[0037] In this specification, "parallel" means a state where the angle formed by two straight lines is greater than -10° and less than 10°, and therefore, also includes a state where the angle is greater than -5° and less than 5°. In addition, "perpendicular" means a state where the angle formed by two straight lines is greater than 80° and less than 100°, and therefore, also includes a state where the angle is greater than 85° and less than 95°.

[0038] In this specification, "film" and "layer" may be interchanged. For example, "conductive layer" may be replaced by "conductive film". Similarly, "insulating film" may be replaced by "insulating layer".

[0039] The triangles, rectangles, trapezoids, pentagons or hexagons in this specification are not in the strict sense, and may be approximate triangles, rectangles, trapezoids, pentagons or hexagons, etc. There may be some small deformations caused by tolerances, and there may be chamfers, arc edges and deformations.

[0040] The term "about" in the present disclosure refers to a numerical value that is not strictly limited to allow for process and measurement errors.

[0041] Figure 1a is a schematic structural diagram of a related series organic light emitting diode device; Figure 1b Schematic diagram of another related series organic light emitting diode device. Figure 1a Schematic diagram of an optical microcavity for a 1-period and 2-period tandem organic light-emitting diode (tandem OLED) device. Figure 1b Schematic diagram of the optical microcavity of a 2-period and 3-period tandem organic light-emitting diode (tandem OLED) device.

[0042] The inventors of this application have found that Figure 1a As shown in FIG. b, the tandem organic light emitting diode (tandem OLED) devices of 1 period and 2 periods and the tandem organic light emitting diode (tandem OLED) devices of 2 periods and 3 periods all include a first electrode 11', a second electrode 12', and a plurality of light emitting layers 13' disposed between the first electrode 11' and the second electrode 12'. The length L1 of the optical microcavity of the tandem organic light emitting diode (tandem OLED) devices of 1 period and 2 periods is less than the length L2 of the optical microcavity of the tandem organic light emitting diode (tandem OLED) devices of 2 periods and 3 periods. The length of the optical microcavity of the tandem organic light emitting diode (tandem OLED) device is the vertical distance between the surface of the first electrode 11' close to the second electrode 12' and the surface of the second electrode 12' close to the first electrode 11'.

[0043] Compared with 1-period and 2-period tandem OLED devices, 2-period and 3-period tandem OLED devices have the advantages of high efficiency and narrow half-peak width. However, the length L2 of the optical microcavity of 2-period and 3-period tandem OLED devices is relatively long, and it is necessary to increase the length of the optical microcavity by adjusting the overall thickness of the device, which results in an increase in the overall thickness of the 2-period and 3-period tandem OLED devices, and increases the driving voltage and power consumption of the 2-period and 3-period tandem OLED devices.

[0044] A driving voltage simulation experiment was carried out on tandem OLED devices with 1 and 2 cycles and tandem OLED devices with 2 and 3 cycles. The driving voltages of the red sub-pixel, green sub-pixel and blue sub-pixel of the tandem OLED devices with 1 and 2 cycles were all 100%; the driving voltage of the red sub-pixel of the tandem OLED devices with 2 and 3 cycles was 108%, the driving voltage of the green sub-pixel was 108%, and the driving voltage of the blue sub-pixel was all 105%.

[0045] It can be seen from the above simulation experiment results that the driving voltage of the 2-cycle and 3-cycle tandem organic light emitting diode (tandem OLED) devices is larger than the driving voltage of the 1-cycle and 2-cycle tandem organic light emitting diode (tandem OLED) devices, and the power consumption is higher.

[0046] Related 2-period and 3-period tandem organic light-emitting diode (tandem OLED) devices generally form the optimal optical microcavity length by increasing the thickness of the hole transport layer (HTL). Since the hole transport layer (HTL) material needs to participate in the electroluminescence of the light-emitting device, the hole transport layer (HTL) needs to meet the material's energy level, mobility and other parameters, making the hole transport layer (HTL) have a low transmittance. Increasing the thickness of the hole transport layer (HTL) will cause the transmittance of the light-emitting device to decrease and reduce light output.

[0047] Figure 1c The graph is a graph showing the transmittance of light of different wavelengths of the display substrate. Curve a is the transmittance of light of different wavelengths of the display substrate with a hole transport layer (HTL) thickness of 60 nanometers; curve b is the transmittance of light of different wavelengths of the display substrate with a hole transport layer (HTL) thickness of 70 nanometers. Figure 1cAs shown in the figure, the transmittance of light of different wavelengths of the display substrate with a hole transport layer (HTL) thickness of 70 nanometers is less than the transmittance of light of different wavelengths of the display substrate with a hole transport layer (HTL) thickness of 60 nanometers. It can be seen that the increase in the thickness of the hole transport layer (HTL) will lead to a decrease in the transmittance of the light-emitting device.

[0048] An embodiment of the present disclosure provides a display substrate, comprising at least one sub-pixel, wherein the at least one sub-pixel comprises a light-emitting device arranged on a substrate, wherein the light-emitting device comprises a first electrode, a light-emitting functional layer and a second electrode which are sequentially stacked in a direction away from the substrate; the light-emitting functional layer comprises at least one light-emitting stack, and the light-emitting stack comprises a light-emitting layer; the first electrode comprises a reflective conductive layer, and the reflective conductive layer is configured to reflect at least part of visible light, and the reflective conductive layer comprises at least one recessed area and a flat area, wherein the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

[0049] Figure 2 FIG. 1 is a schematic diagram of the structure of a display device. Figure 2 As shown, the display device may include: a timing controller, a data driver, a scan driver, a light-emitting driver and a pixel array. The timing controller is connected to the data driver, the scan driver and the light-emitting driver respectively. The data driver is connected to a plurality of data signal lines (for example, D1 to Dn), the scan driver is connected to a plurality of scan signal lines (for example, S1 to Sm), and the light-emitting driver is connected to a plurality of light-emitting control lines (for example, E1 to Eo). Among them, n, m and o can be natural numbers. The pixel array may include at least two sub-pixels Pxij, and i and j can be natural numbers. At least one sub-pixel Pxij may include: a pixel circuit and a light-emitting device connected to the pixel circuit. The pixel circuit may be connected to the scan signal line, the light-emitting control line and the data signal line, respectively.

[0050] In some exemplary embodiments, the timing controller may provide a grayscale value and a control signal suitable for the specifications of the data driver to the data driver, a clock signal, a scan start signal, etc. suitable for the specifications of the scan driver to the scan driver, and a clock signal, an emission stop signal, etc. suitable for the specifications of the light emitting driver to the light emitting driver. The data driver may generate a data voltage to be provided to the data signal lines D1, D2, D3, ... and Dn using the grayscale value and the control signal received from the timing controller. For example, the data driver may sample the grayscale value using the clock signal, and apply the data voltage corresponding to the grayscale value to the data signal lines D1 to Dn in units of pixel rows. The scan driver may generate a scan signal to be provided to the scan signal lines S1, S2, S3, ... and Sm by receiving a clock signal, a scan start signal, etc. from the timing controller. For example, the scan driver may sequentially provide a scan signal having an on-level pulse to the scan signal lines S1 to Sm. For example, the scan driver may be constructed in the form of a shift register, and may generate a scan signal in a manner that a scan start signal provided in the form of an on-level pulse is sequentially transmitted to a next-level circuit under the control of a clock signal. The light-emitting driver may generate a light-emitting control signal to be provided to the light-emitting control lines E1, E2, E3, ... and Eo by receiving a clock signal, an emission stop signal, etc. from a timing controller. For example, the light-emitting driver may sequentially provide an emission signal with an off-level pulse to the light-emitting control lines E1 to Eo. For example, the light-emitting driver may be constructed in the form of a shift register, and may generate a light-emitting control signal in a manner that an emission stop signal provided in the form of an off-level pulse is sequentially transmitted to a next-level circuit under the control of a clock signal.

[0051] Figure 3 FIG. 1 is a schematic diagram of a planar structure of a display area in a display device. Figure 3 As shown, the display area of ​​the display device may include a plurality of pixel units P arranged in a matrix, at least one of the plurality of pixel units P includes a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light, and the first sub-pixel P1, the second sub-pixel P2, and the third sub-pixel P3 each include a pixel driving circuit and a light-emitting device. The pixel driving circuits in the sub-pixels are respectively connected to the scanning signal lines and the data signal lines, and the pixel driving circuits are configured to receive the data voltage transmitted by the data signal lines under the control of the scanning signal lines, and output corresponding currents to the display light-emitting devices. The display light-emitting devices in the sub-pixels are respectively connected to the pixel driving circuits of the sub-pixels in which they are located, and the display light-emitting devices are configured to emit light of corresponding brightness in response to the current output by the pixel driving circuit of the sub-pixels in which they are located.

[0052] In an exemplary embodiment, the first sub-pixel P1 may be a red sub-pixel emitting red (R) light, the second sub-pixel P2 may be a green sub-pixel emitting green (G) light, and the third sub-pixel P3 may be a blue sub-pixel emitting blue (B) light. In an exemplary embodiment, the shape of the sub-pixels may be any one or more of a triangle, a square, a rectangle, a rhombus, a trapezoid, a parallelogram, a pentagon, a hexagon, and other polygons, and may be arranged in a horizontal parallel arrangement, a vertical parallel arrangement, an X shape, a cross shape, a herringbone shape, a square shape, a diamond shape, or a delta shape, which is not limited in the present disclosure.

[0053] In an exemplary embodiment, a pixel unit may include four sub-pixels, which is not limited in the present disclosure.

[0054] Figure 4 is a schematic diagram of a cross-sectional structure of a display area of ​​a display device, wherein: Figure 4 Can be Figure 3 Cross-sectional view along the A-A' direction. Figure 4 The display device shown in the figure is a structure that uses white light + color film to achieve full color. Figure 4 As shown, in a direction perpendicular to the display device, the display device may include: a substrate 101, a driving circuit layer 102 disposed on the substrate 101, a light emitting structure layer 103 disposed on a side of the driving circuit layer 102 away from the substrate 101, a first encapsulation layer 104 disposed on a side of the light emitting structure layer 103 away from the substrate 101, a color film structure layer 105 disposed on a side of the first encapsulation layer 104 away from the substrate 101, a second encapsulation layer 106 disposed on a side of the color film structure layer 105 away from the substrate 101, and a cover layer 107 disposed on a side of the second encapsulation layer 106 away from the substrate 101. In some possible implementations, the display device may include other film layers, such as a touch structure layer, etc., which is not limited in the present disclosure.

[0055] In an exemplary embodiment, the driving circuit layer 102 can be prepared on the substrate 101 by a silicon semiconductor process (such as a CMOS process), and the driving circuit layer 102 may include a pixel driving circuit, and the pixel driving circuit is respectively connected to the scanning signal line and the data signal line, and the pixel driving circuit may include a plurality of transistors and a storage capacitor. The transistor may include a control electrode G, a first electrode S, and a second electrode D, and the control electrode G, the first electrode S, and the second electrode D may be respectively connected to corresponding connection electrodes through vias filled with tungsten metal (i.e., tungsten vias, W-vias), and may be connected to other electrical structures (such as routing, etc.) through the connection electrodes.

[0056] In an exemplary embodiment, the light-emitting structure layer 103 may include a plurality of light-emitting devices, and the light-emitting devices may include at least a first electrode, a light-emitting functional layer, and a second electrode stacked in sequence along a direction away from the substrate. The first electrode may be connected to the second electrode D of the transistor through a connecting electrode, the light-emitting functional layer is connected to the first electrode, the second electrode is connected to the light-emitting functional layer, and the second electrode is connected to a voltage line. The light-emitting functional layer emits light when driven by the first electrode and the second electrode.

[0057] In an exemplary embodiment, the display substrate of the embodiment of the present disclosure also includes a pixel definition layer, which is arranged on the side of the first electrode away from the substrate, and the pixel definition layer is provided with a pixel opening that defines a sub-pixel, and the pixel opening exposes at least a portion of the first electrode. The light-emitting functional layer covers the pixel opening and is in contact with the first electrode exposed by the pixel opening, and the second electrode is in contact with the light-emitting functional layer.

[0058] In an exemplary embodiment, the light-emitting functional layer may include at least one light-emitting stack, and the light-emitting stack may include a light-emitting layer (EML for short), and any one or more of the following: a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). Among them, some film layers in the light-emitting functional layers of multiple sub-pixels may be common layers connected together.

[0059] In an exemplary embodiment, the light-emitting device may be a tandem light-emitting device. The light-emitting functional layer of the tandem light-emitting device includes at least two light-emitting stacks stacked in a direction perpendicular to the substrate and connected in series, and a charge generation layer is provided between two adjacent light-emitting stacks, and the charge generation layer generates holes and electrons under the voltage of the first electrode and the second electrode.

[0060] In an exemplary embodiment, the color film structure layer 105 may include a black matrix (BM) and a color filter (CF), the position of the color filter may correspond to the position of the light-emitting device, the black matrix may be located between adjacent color filters, and the color filter is configured to filter the light emitted by the light-emitting device into red (R) light, green (G) light, and blue (B) light to form red sub-pixels, green sub-pixels, and blue sub-pixels.

[0061] In an exemplary embodiment, the first encapsulation layer 104 and the second encapsulation layer 106 may be made of thin film encapsulation (TFE) to ensure that external water vapor cannot enter the light-emitting structure layer. The cover layer 107 may be made of glass or a flexible plastic colorless polyimide.

[0062] Figure 5FIG. 1 is a schematic diagram of a planar structure of a first electrode of a display substrate according to an embodiment of the present disclosure. In an exemplary embodiment, Figure 5 As shown, the display substrate of the embodiment of the present disclosure includes a plurality of pixel units, and the pixel units include a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light; for example, the first sub-pixel P1 is a red sub-pixel emitting a red light, the second sub-pixel P2 is a green sub-pixel emitting a green light, and the third sub-pixel P3 is a blue sub-pixel emitting a blue light. The shapes of the first sub-pixel P1, the second sub-pixel P2, and the third sub-pixel P3 are all rectangular or rounded rectangular, and the first sub-pixel P1, the second sub-pixel P2, and the third sub-pixel P3 are arranged in a triangle.

[0063] In an exemplary embodiment, the first subpixel P1, the second subpixel P2, and the third subpixel P3 all include a light-emitting device, which includes a first electrode 11, a light-emitting functional layer, and a second electrode sequentially arranged in a direction away from the substrate, and the light-emitting functional layer emits light under the drive of the first electrode and the second electrode. Among them, the first electrode 11 can be called an anode, and the second electrode can be called a cathode.

[0064] In an exemplary embodiment, the first electrode 11 is in a rectangular or rounded rectangular shape. The first electrode 11 includes a reflective conductive layer 20, which can reflect incident light toward the second electrode.

[0065] In some embodiments, the shape of the first electrode may also be circular, elliptical, triangular, rhombus, trapezoidal, pentagonal, hexagonal, or other polygonal shapes, which will not be described in detail in the present disclosure.

[0066] In an exemplary embodiment, the reflective conductive layer 20 includes a recessed area 20-1 and a flat area 20-2 located at least on one side of the recessed area 20-1, for example, the flat area 20-2 is arranged around the recessed area 20-1. The recessed area 20-1 is in a rectangular shape or a rounded rectangular shape, and the recessed area 20-1 is located in the middle area of ​​the reflective conductive layer 20. The flat area 20-2 is in a rectangular ring shape or a rounded rectangular ring shape, and the flat area 20-2 is located in the peripheral area of ​​the reflective conductive layer 20, and the flat area 20-2 is arranged around the recessed area 20-1, and the flat area 20-2 is connected to the recessed area 20-1.

[0067] Figure 6 Schematic diagram of the cross-sectional structure of a first electrode of a display substrate according to an embodiment of the present disclosure; wherein: Figure 6 Can be Figure 5 The cross-sectional view along the B-B' direction, Figure 6Schematic diagram of the cross-sectional structure of the first electrode of a sub-pixel (third sub-pixel). In an exemplary embodiment, Figure 5 and Figure 6 As shown, in the direction perpendicular to the display substrate, the first electrode 11 of the display substrate of the embodiment of the present disclosure includes a first light-transmitting conductive layer 21, a reflective conductive layer 20, and a second light-transmitting conductive layer 22 which are sequentially stacked along a direction away from the substrate, a surface of the first light-transmitting conductive layer 21 away from the substrate is in contact with a surface of the reflective conductive layer 20 close to the substrate, a surface of the reflective conductive layer 20 away from the substrate is in contact with a surface of the second light-transmitting conductive layer 22 close to the substrate, and a surface of the second light-transmitting conductive layer 22 away from the substrate is in contact with the pixel definition layer 31.

[0068] In an exemplary embodiment, the reflective conductive layer 20 includes a recessed area 20-1 and a flat area 20-2, the surface of the recessed area 20-1 away from the substrate is recessed toward the substrate compared to the surface of the flat area 20-2 away from the substrate, the orthographic projection of the recessed area 20-1 on the substrate overlaps at least partially with the orthographic projection of the light-emitting functional layer of the light-emitting device on the substrate, and the orthographic projection of the flat area 20-2 on the substrate overlaps at least partially with the orthographic projection of the pixel definition layer 31 on the substrate. The thickness of the recessed area 20-1 of the reflective conductive layer 20 is h5, and the thickness of the flat area 20-2 is h3. The thickness of the recessed area 20-1 and the thickness of the flat area 20-2 satisfy the relationship: h3>h5. Among them, the thickness of the recessed area 20-1 is the average size of the recessed area 20-1 in the direction perpendicular to the substrate, and the thickness of the flat area 20-2 is the average size of the flat area 20-2 in the direction perpendicular to the substrate.

[0069] In an exemplary embodiment, the thickness h3 of the flat region 20 - 2 is in the range of 80 nm ≤ h3 ≤ 120 nm. For example, the thickness h3 of the flat region 20 - 2 is in the range of 90 nm ≤ h3 ≤ 110 nm.

[0070] The disclosed embodiment shows that the thickness of the substrate through the flat area 20 - 2 is greater than or equal to 80 nm and less than or equal to 120 nm, thereby preventing the recessed area 20 - 1 from causing light leakage in the reflective conductive layer 20 and ensuring that the reflective conductive layer 20 can reflect visible light.

[0071] In an exemplary embodiment, the cross-sectional shape of the recessed region 20 - 1 in a direction perpendicular to the substrate is an inverted trapezoid. In some embodiments, the cross-sectional shape of the recessed region in a direction perpendicular to the substrate can be a rectangle, a regular trapezoid, or other shapes.

[0072] In an exemplary embodiment, the recessed area 20-1 includes a bottom wall 201 and a side wall 202. The bottom wall 201 is the surface of the recessed area 20-1 close to the substrate. The bottom wall 201 can be a plane that is roughly parallel to the plane where the substrate is located. The side wall 202 is arranged around the bottom wall 201. The angle formed between the side wall 202 and the plane where the substrate is located is less than 90 degrees. One end of the side wall 202 is connected to the bottom wall 201, and the other end of the side wall 202 is connected to the flat area 20-2.

[0073] The embodiment of the present disclosure shows that the substrate includes a recessed area 20-1 through the reflective conductive layer 20. Compared with the light-emitting device in which the reflective conductive layer does not form a recessed area, the thickness of the light-emitting device of the display substrate can be reduced, and the length of the optical microcavity of the light-emitting device is ensured to remain unchanged, thereby reducing the driving voltage of the light-emitting device. The length of the optical microcavity of the light-emitting device is the vertical distance between the surface of the recessed area 20-1 of the reflective conductive layer 20 away from the substrate and the surface of the second electrode close to the substrate.

[0074] The display substrate of the embodiment of the present disclosure includes a recessed area 20-1 through the reflective conductive layer 20. Compared with the light-emitting device in which the reflective conductive layer does not form a recessed area, the thickness of the light-emitting device of the display substrate can be reduced. Due to the recessed area 20-1 of the reflective conductive layer 20, the vertical distance from the light-emitting layer to the reflective conductive layer 20 in the light-emitting device is not reduced, thereby avoiding the occurrence of the surface plasmon resonance effect and ensuring that the light extraction efficiency of the light-emitting device is reduced.

[0075] In an exemplary embodiment, the vertical distance between the surface of the side of the recessed region 20-1 away from the substrate and the surface of the side of the flat region 20-2 away from the substrate is h1, and the vertical distance between the surface of the side of the recessed region 20-1 away from the substrate and the surface of the side of the flat region 20-2 away from the substrate is in the range of 30nm≤h1≤100nm. For example, the vertical distance between the surface of the side of the recessed region 20-1 away from the substrate and the surface of the side of the flat region 20-2 away from the substrate is in the range of 50nm≤h1≤80nm.

[0076] In an exemplary embodiment, in sub-pixels emitting different colors, the vertical distances h1 between the surface of the recessed area 20-1 away from the substrate and the surface of the flat area 20-2 away from the substrate are different. For example, at least two of the vertical distances h1 between the surface of the recessed area 20-1 away from the substrate and the surface of the flat area 20-2 away from the substrate in the first sub-pixel P1, the vertical distance h1 between the surface of the recessed area 20-1 away from the substrate and the surface of the flat area 20-2 away from the substrate in the second sub-pixel P2, and the vertical distance h1 between the surface of the recessed area 20-1 away from the substrate and the surface of the flat area 20-2 away from the substrate in the third sub-pixel P3 are different from each other.

[0077] The disclosed embodiment shows that in the sub-pixels emitting different colors, the vertical distance h1 between the recessed area 20-1 away from the surface of one side of the substrate and the flat area 20-2 away from the surface of one side of the substrate is different, thereby reducing the difference in the operating voltages of the sub-pixels emitting different colors and ensuring that the operating voltages of the sub-pixels emitting different colors are roughly the same.

[0078] In some embodiments, in sub-pixels emitting different colors, the vertical distances between the surface of the recessed area away from the substrate and the surface of the flat area 20-2 away from the substrate may be substantially equal. For example, the vertical distance between the surface of the recessed area of ​​the first sub-pixel away from the substrate and the surface of the flat area away from the substrate, the vertical distance between the surface of the recessed area of ​​the second sub-pixel away from the substrate and the surface of the flat area away from the substrate, and the vertical distance between the surface of the recessed area of ​​the third sub-pixel away from the substrate and the surface of the flat area away from the substrate are substantially equal.

[0079] The disclosed embodiment shows that the vertical distance between the surface of the recessed area away from the substrate and the surface of the flat area 20 - 2 away from the substrate can be roughly equal when the substrate emits sub-pixels of different colors, thereby simplifying the process flow and saving costs.

[0080] In an exemplary embodiment, the reflectivity of the reflective conductive layer 20 to visible light is greater than or equal to 90%, and the material of the reflective conductive layer 20 may be a conductive metal, such as silver, aluminum, or the like.

[0081] In some embodiments, the first electrode may be a single-layer structure, and the first electrode includes only a reflective conductive layer; or the first electrode may include a reflective conductive layer and other light-transmitting conductive layers, for example, the first electrode may include a reflective conductive layer, and 1, 3, 4, 5, etc. light-transmitting conductive layers. This disclosure will not be repeated here.

[0082] In an exemplary embodiment, the first light-transmitting conductive layer 21 may be a light-transmitting material, and the light transmittance of the first light-transmitting conductive layer 21 to visible light is greater than 90%. For example, the material of the first light-transmitting conductive layer 21 may be a metal oxide, such as indium tin oxide or indium zinc oxide.

[0083] In an exemplary embodiment, the thickness of the first light-transmitting conductive layer 21 is h2, and the range of the thickness of the first light-transmitting conductive layer 21 is: 5nm≤h2≤15nm. For example, the range of the thickness of the first light-transmitting conductive layer 21 is: 8nm≤h2≤12nm. The thickness h2 of the first light-transmitting conductive layer 21 is the average size of the first light-transmitting conductive layer 21 in a direction perpendicular to the substrate.

[0084] In an exemplary embodiment, the second light-transmitting conductive layer 22 may be a light-transmitting material, and the transmittance of the second light-transmitting conductive layer 22 to visible light is greater than 90%. For example, the material of the second light-transmitting conductive layer 22 may be a metal oxide, such as indium tin oxide or indium zinc oxide.

[0085] In an exemplary embodiment, the thickness of the second light-transmitting conductive layer 22 is h4, and the range of the thickness of the second light-transmitting conductive layer 22 is: 5nm≤h4≤15nm. For example, the range of the thickness of the second light-transmitting conductive layer 22 is: 8nm≤h4≤12nm. The thickness h4 of the second light-transmitting conductive layer 22 is the average size of the second light-transmitting conductive layer 22 in a direction perpendicular to the substrate.

[0086] Will Figure 6 The display substrate, the first related display substrate and the second related display substrate shown in the figure were subjected to a simulation experiment of driving voltage, wherein no recessed area was formed on the reflective conductive layer of the first related display substrate, no recessed area was formed on the reflective conductive layer of the second related display substrate, and a light-transmitting layer was formed on the reflective conductive layer. Figure 6 The driving voltage of the light-emitting device of the display substrate shown is 94%, and the luminous efficiency is 102%; the driving voltage of the light-emitting device of the first related display substrate is 100%, and the luminous efficiency is 100%; the driving voltage of the light-emitting device of the second related display substrate is 95%, and the luminous efficiency is 99%.

[0087] According to the results of the above simulation experiments, the embodiment of the present disclosure shows that the substrate includes a recessed area 20 - 1 through the reflective conductive layer 20 , which can reduce the driving voltage of the light-emitting device and improve the light-emitting efficiency of the light-emitting device.

[0088] In an exemplary embodiment, the first electrode 11 further includes a light-transmitting structure layer 23, which is disposed in the recessed region 20-1, and is located between the reflective conductive layer 20 and the second light-transmitting conductive layer 22. The orthographic projection of the light-transmitting structure layer 23 on the substrate completely overlaps with the orthographic projection of the recessed region 20-1 on the substrate, and the orthographic projection of the light-transmitting structure layer 23 on the substrate does not overlap with the orthographic projection of the flat region 20-2 on the substrate, and the entire light-transmitting structure layer 23 is located in the recessed region 20-1 of the reflective conductive layer 20, filling up the recessed region 20-1 of the reflective conductive layer 20. The side of the light-transmitting structure layer 23 contacts the side wall 202 of the recessed area 20-1, the surface of the light-transmitting structure layer 23 close to the substrate contacts the bottom wall 201 of the recessed area 20-1, the surface of the light-transmitting structure layer 23 away from the substrate contacts the second light-transmitting conductive layer 22, and the surface of the light-transmitting structure layer 23 away from the substrate is roughly flush with the surface of the flat area 20-2 away from the substrate, forming a planar structure. The orthographic projection of the second light-transmitting conductive layer 22 on the substrate covers the orthographic projection of the light-transmitting structure layer 23 on the substrate, and the second light-transmitting conductive layer 22 contacts the surface of the light-transmitting structure layer 23 away from the substrate.

[0089] The display substrate of the embodiment of the present disclosure increases the light transmittance of the light emitting device of the display substrate and improves the light extraction efficiency of the light emitting device by disposing a light-transmitting structural layer 23 in the recessed area 20 - 1 .

[0090] In an exemplary embodiment, the light-transmitting structural layer 23 is a light-transmitting layer, the transmittance of the light-transmitting layer to visible light is greater than or equal to 95%, and the material of the light-transmitting layer is an inorganic material or a metal oxide, for example, the material of the light-transmitting layer is silicon nitride, silicon oxynitride, indium tin oxide or indium zinc oxide.

[0091] In an exemplary embodiment, the display substrate of the disclosed embodiment further includes a pixel definition layer 31, which is disposed on the side of the first electrode 11 away from the substrate, and a pixel opening 32 is disposed in the pixel definition layer 31, wherein the pixel opening 32 exposes at least a portion of the surface of the first electrode 11 away from the substrate, and the orthographic projection of the pixel opening 32 on the substrate overlaps at least a portion of the orthographic projection of the recessed area 20-1 of the first electrode 11 on the substrate. For example, the orthographic projection of the pixel opening 32 on the substrate covers the orthographic projection of the recessed area 20-1 of the first electrode 11 on the substrate.

[0092] In some embodiments, the surface of the reflective conductive layer away from the substrate may include a plurality of recessed areas arranged at intervals, and each recessed area is connected to a flat area on all sides. The embodiments of the present disclosure will not be described in detail here.

[0093] The present disclosure discloses a method for preparing a first electrode of a display substrate, comprising: Step (1), forming a driving circuit layer on a substrate; Step (2), forming a first light-transmitting conductive layer on the driving circuit layer by a plasma enhanced chemical vapor deposition (PECVD) process; then, forming a reflective conductive film on the first light-transmitting conductive layer by a sputtering process; Step (3), half-etching the reflective conductive film by a wet etching process, so that the reflective conductive film forms a reflective conductive layer; the reflective conductive layer includes a recessed area; Step (4), depositing a light-transmitting film on the reflective conductive layer, and forming the light-transmitting film into a light-transmitting structure layer filling the recessed area through a patterning process; Step (5), forming a second light-transmitting conductive layer covering the light-transmitting structural layer on the reflective conductive layer by a plasma enhanced chemical vapor deposition (PECVD) process, thereby completing the preparation of the first electrode.

[0094] Figure 7 The cross-sectional structure diagram of a light-emitting device of a display substrate according to an embodiment of the present disclosure is shown in FIG. Figure 7 FIG. 1 is a schematic cross-sectional structure diagram of a light emitting device having three sub-pixels (a first sub-pixel P1, a second sub-pixel P2, and a third sub-pixel P3). Figure 7 As shown, in a direction perpendicular to the display substrate, the light-emitting device of the display substrate of the embodiment of the present disclosure includes a first electrode 11, a light-emitting functional layer 12, and a second electrode 13 which are sequentially stacked in a direction away from the substrate 101. The light-emitting functional layer 12 is located between the first electrode 11 and the second electrode 13, and is in contact with the first electrode 11 and the second electrode 13, respectively. The light-emitting functional layer 12 may include a first light-emitting stack 12-1 and a second light-emitting stack 12-2 which are sequentially stacked in a direction away from the substrate, and a charge generation layer 30 which is arranged between the first light-emitting stack 12-1 and the second light-emitting stack 12-2.

[0095] In an exemplary embodiment, the first light-emitting stack 12 - 1 is located on a side of the second light-emitting stack 12 - 2 close to the substrate, and is connected in series with the second light-emitting stack 12 - 2 via the charge generation layer 30 .

[0096] The embodiment of the present disclosure shows that the substrate can achieve the effect of emitting white light by superimposing the light emitted by the first light-emitting stack 12 - 1 and the light emitted by the second light-emitting stack 12 - 2 .

[0097] In an exemplary embodiment, the first light-emitting stack 12-1 may include a first hole injection layer 41, a first hole transport layer 42, a first light-emitting layer 43 and a first electron transport layer 44 stacked in sequence along a direction away from the substrate 101, the first hole injection layer 41 is in contact with the first electrode 11 on a surface close to the substrate 101, and the first electron transport layer 44 is in contact with the charge generation layer 30 on a surface away from the substrate 101.

[0098] In an exemplary embodiment, the charge generation layer 30 may include a first generation layer 30-1 and a second generation layer 30-2 sequentially arranged in a direction away from the substrate 101, and the first generation layer 30-1 and the second generation layer 30-2 are in contact with each other. The first generation layer 30-1 is located on the side of the second generation layer 30-2 close to the substrate, and the first generation layer 30-1 may be an N-type charge generation layer. The second generation layer 30-2 is located on the side of the first generation layer 30-1 away from the substrate, and the second generation layer 30-2 may be a P-type charge generation layer.

[0099] In an exemplary embodiment, the second light-emitting stack 12-2 may include a second hole transport layer 45, a second light-emitting layer 46, a second electron transport layer 47 and an electron injection layer 48 stacked in sequence along a direction away from the substrate 101, the second hole transport layer 45 is in contact with the charge generation layer 30 on a surface close to the substrate 101, and the electron injection layer 48 is in contact with the second electrode 13 on a surface away from the substrate 101.

[0100] In an exemplary embodiment, the orthographic projections of the first light-emitting layer 43 and the second light-emitting layer 46 of the light-emitting device on the substrate both cover the orthographic projections of the recessed area of ​​the first electrode 11 of the light-emitting device on the substrate, and the orthographic projections of the first light-emitting layer 43 and the second light-emitting layer 46 of the light-emitting device on the substrate both cover the orthographic projections of the light-transmitting structure layer 23 of the first electrode 11 of the light-emitting device on the substrate.

[0101] Figure 8 FIG. 1 is a schematic cross-sectional structure diagram of another first electrode of a display substrate according to an embodiment of the present disclosure. Figure 8 As shown, this exemplary embodiment shows the structure of the first electrode of the substrate Figure 6 The structures of the first electrodes of the substrates shown in the embodiments are substantially the same, except that Figure 8 As shown, the structure of the light-transmitting structure layer 23 of the substrate shown in the embodiment of the present disclosure is different.

[0102] In an exemplary embodiment, in a direction perpendicular to the display substrate, the light-transmitting structure layer 23 of the display substrate of the embodiment of the present disclosure includes a first light-transmitting layer 23-1 and a second light-transmitting layer 23-2 arranged in sequence along a direction away from the substrate, the first light-transmitting layer 23-1 is arranged on the side of the second light-transmitting layer 23-2 close to the substrate, and contacts the bottom wall of the recessed area 20-1; the second light-transmitting layer 23-2 contacts the surface of the first light-transmitting layer 23-1 away from the substrate, and the surface of the second light-transmitting layer 23-2 away from the substrate contacts the second light-transmitting conductive layer 22.

[0103] In an exemplary embodiment, the refractive index of the first light-transmitting layer 23-1 is greater than the refractive index of the second light-transmitting layer 23-2. For example, the refractive index of the first light-transmitting layer 23-1 is greater than or equal to 1.8 and less than or equal to 2.5, and the refractive index of the second light-transmitting layer 23-2 is greater than or equal to 1.5 and less than or equal to 2.2.

[0104] In some embodiments, the light-transmitting structure layer may also include other numbers of light-transmitting layers. For example, the light-transmitting structure layer includes 3, 4, 5, 6, etc. light-transmitting layers arranged in sequence along the direction away from the substrate, and the refractive index of the light-transmitting layer of the light-transmitting structure layer decreases in sequence along the direction away from the substrate.

[0105] Will Figure 6 The display substrate shown is Figure 8 The display substrate is shown in the light extraction efficiency simulation experiment. Figure 6 The light extraction efficiencies of the first sub-pixel, the second sub-pixel, and the third sub-pixel of the display substrate are all 100%; Figure 8 The light extraction efficiency of the first sub-pixel and the second sub-pixel of the display substrate is 101%, and the light extraction efficiency of the third sub-pixel is 102%.

[0106] It can be seen from the above simulation experiment results that the light-transmitting structure layer 23 including multiple light-transmitting layers with different refractive indices can improve the light extraction efficiency of the light-emitting device.

[0107] The present disclosure also provides a method for preparing a display substrate, comprising: At least one sub-pixel is formed, the at least one sub-pixel includes a light-emitting device, the light-emitting device includes a first electrode, a light-emitting functional layer and a second electrode which are sequentially stacked in a direction away from the substrate; the light-emitting functional layer includes at least one light-emitting stack, the light-emitting stack includes a light-emitting layer; the first electrode includes a reflective conductive layer, the reflective conductive layer is configured to reflect at least part of the visible light, the reflective conductive layer includes at least one recessed area and a flat area, the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

[0108] The embodiment of the present disclosure further provides a display device, including any of the above-mentioned display substrates. The display device can be: a mobile phone, a wearable device, an AR or VR display device, a vehicle-mounted display device, a tablet computer, a television, a display, a laptop computer, a digital photo frame, a navigator, or any other product or component with a display function, and the embodiment of the present invention is not limited thereto.

[0109] Although the embodiments disclosed in the present disclosure are as above, the contents described are only embodiments adopted to facilitate understanding of the present disclosure and are not intended to limit the present invention. Any technician in the relevant field can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present disclosure, but the patent protection scope of the present invention shall still be subject to the scope defined by the attached claims.

Claims

1. A display substrate, characterized in that: The device comprises at least one sub-pixel, wherein the at least one sub-pixel comprises a light-emitting device disposed on a substrate, wherein the light-emitting device comprises a first electrode, a light-emitting functional layer and a second electrode which are sequentially stacked in a direction away from the substrate; The light-emitting functional layer includes at least one light-emitting stack, and the light-emitting stack includes a light-emitting layer; the first electrode includes a reflective conductive layer, and the reflective conductive layer is configured to reflect at least part of the visible light, and the reflective conductive layer includes at least one recessed area and a flat area, and the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

2. The display substrate according to claim 1, characterized in that: The thickness of the flat region is greater than the thickness of the concave region, and the concave region is concave in a direction closer to the substrate than the surface of the flat region is in a direction closer to the substrate.

3. The display substrate according to claim 1, characterized in that: A vertical distance between the at least one recessed area away from the surface of one side of the substrate and the flat area away from the surface of one side of the substrate is greater than or equal to 30 nanometers and less than or equal to 100 nanometers.

4. The display substrate according to claim 1, characterized in that: The at least one sub-pixel comprises a first sub-pixel emitting a first color light, a second sub-pixel emitting a second color light, and a third sub-pixel emitting a third color light, wherein a vertical distance between at least one recessed area in the first sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate, a vertical distance between at least one recessed area in the second sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate, and a vertical distance between at least one recessed area in the third sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate are substantially equal; or, at least two of the vertical distance between at least one recessed area in the first sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate, a vertical distance between at least one recessed area in the second sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate, and a vertical distance between at least one recessed area in the third sub-pixel away from the one side surface of the substrate and the flat area away from the one side surface of the substrate are different from each other.

5. The display substrate according to claim 1, characterized in that: The thickness of the flat area is greater than or equal to 80 nanometers and less than or equal to 120 nanometers.

6. The display substrate according to claim 1, characterized in that: The shape of the at least one recessed area includes at least one of a circle, an ellipse, a triangle, a rectangle, a rhombus, a trapezoid, a pentagon, and a hexagon.

7. The display substrate according to any one of claims 1 to 6, characterized in that: The first electrode further includes a light-transmitting structure layer, at least a portion of which is disposed in the at least one recessed region.

8. The display substrate according to claim 7, characterized in that: The at least one recessed area includes a bottom wall and a side wall, and the light-transmitting structure layer is in contact with the bottom wall and the side wall.

9. The display substrate according to claim 7, characterized in that: A surface of the light-transmitting structure layer away from the substrate is substantially flush with a surface of the flat region away from the substrate.

10. The display substrate according to claim 7, characterized in that: The light-transmitting structural layer includes a light-transmitting layer.

11. The display substrate according to claim 7, characterized in that: The light-transmitting structural layer comprises at least two light-transmitting layers, the at least two light-transmitting layers are arranged in sequence along a direction away from the substrate, and the refractive indices of the at least two light-transmitting layers decrease in sequence along the direction away from the substrate.

12. The display substrate according to claim 11, characterized in that: The light-transmitting structure layer includes a first light-transmitting layer and a second light-transmitting layer arranged in sequence along a direction away from the substrate, the refractive index of the first light-transmitting layer is greater than the refractive index of the second light-transmitting layer, the refractive index of the first light-transmitting layer is greater than or equal to 1.8 and less than or equal to 2.5, and the refractive index of the second light-transmitting layer is greater than or equal to 1.5 and less than or equal to 2.

2.

13. The display substrate according to claim 7, characterized in that: The light transmittance of the light-transmitting structural layer to visible light is greater than or equal to 95%.

14. The display substrate according to claim 7, characterized in that: The light-transmitting structural layer includes at least one of silicon nitride, silicon oxynitride, indium tin oxide and indium zinc oxide.

15. The display substrate according to any one of claims 1 to 6, characterized in that: The first electrode also includes a first light-transmitting conductive layer and a second light-transmitting conductive layer, the first light-transmitting conductive layer is arranged on the side of the reflective conductive layer close to the substrate, and the surface of the first light-transmitting conductive layer away from the substrate is in contact with the surface of the reflective conductive layer close to the substrate, and the second light-transmitting conductive layer is arranged on the side of the reflective conductive layer away from the substrate, and the surface of the second light-transmitting conductive layer close to the substrate is in contact with the surface of the flat area of ​​the reflective conductive layer away from the substrate.

16. The display substrate according to claim 15, characterized in that: The thickness of the first light-transmitting conductive layer is greater than or equal to 5 nanometers and less than or equal to 15 nanometers; the thickness of the second light-transmitting conductive layer is greater than or equal to 5 nanometers and less than or equal to 15 nanometers.

17. The display substrate according to any one of claims 1 to 6, characterized in that: The reflectivity of the reflective conductive layer to visible light is greater than or equal to 90%.

18. The display substrate according to any one of claims 1 to 6, characterized in that: It also includes a pixel definition layer, which is arranged on the side of the first electrode away from the substrate, and a pixel opening is arranged in the pixel definition layer, and the pixel opening exposes at least a portion of the first electrode, and the orthographic projection of the pixel opening on the substrate overlaps with at least a portion of the orthographic projection of the at least one recessed area on the substrate.

19. A method for preparing a display substrate, characterized in that: include: forming at least one sub-pixel, wherein the at least one sub-pixel comprises a light-emitting device, wherein the light-emitting device comprises a first electrode, a light-emitting functional layer, and a second electrode which are sequentially stacked in a direction away from the substrate; The light-emitting functional layer includes at least one light-emitting stack, and the light-emitting stack includes a light-emitting layer; the first electrode includes a reflective conductive layer, and the reflective conductive layer is configured to reflect at least part of the visible light, and the reflective conductive layer includes at least one recessed area and a flat area, and the flat area is located around the at least one recessed area, and the orthographic projection of the at least one recessed area on the substrate overlaps with the orthographic projection of at least part of the light-emitting layer on the substrate.

20. A display device, characterized in that: It comprises the display substrate as claimed in any one of claims 1 to 18.

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