Display substrate and display device

Abstract

The invention discloses a display substrate and a display device. The display substrate includes a substrate and a plurality of light-emitting devices disposed on the substrate, the plurality of light-emitting devices including a red light-emitting device including a red light-emitting layer, a green light-emitting device including a green light-emitting layer, and a blue light-emitting device including a blue light-emitting layer; the material of the red light-emitting layer comprises a red doping material; the material of the green light-emitting layer comprises a green doping material, and the material of the blue light-emitting layer comprises two blue doping materials; or, the materials of the green light-emitting layer comprise two green doping materials, and the materials of the blue light-emitting layer comprise two blue doping materials; wherein the wavelengths corresponding to the peak values of the photoluminescence spectrum curves of the two green doped materials are different, and the wavelengths corresponding to the peak values of the photoluminescence spectrum curves of the two blue doped materials are different.

Description

Technical Field

[0001] The present invention relates to but is not limited to display technology, and in particular to a display substrate and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) is an active light-emitting display device with the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, and extremely high response speed. With the continuous development of display technology, display devices using OLED as the light-emitting element and thin film transistor (TFT) for signal control have become the mainstream products in the current display field.

[0003] However, display products have color shift problems at different viewing angles. Summary of the invention

[0004] 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.

[0005] Embodiments of the present application provide a display substrate and a display device to solve the problem of color shift of display products at different viewing angles.

[0006] On the one hand, an embodiment of the present disclosure provides a display substrate, comprising: a substrate and a plurality of light-emitting devices arranged on the substrate, the plurality of light-emitting devices comprising a red light-emitting device, a green light-emitting device and a blue light-emitting device, the red light-emitting device comprising a red light-emitting layer, the green light-emitting device comprising a green light-emitting layer, and the blue light-emitting device comprising a blue light-emitting layer; the material of the red light-emitting layer comprises a red doping material; the material of the green light-emitting layer comprises a green doping material, and the material of the blue light-emitting layer comprises two blue doping materials; or, the material of the green light-emitting layer comprises two green doping materials, and the material of the blue light-emitting layer comprises two blue doping materials; wherein the peaks of the photoluminescence spectrum curves of the two green doping materials correspond to different wavelengths, and the peaks of the photoluminescence spectrum curves of the two blue doping materials correspond to different wavelengths.

[0007] In an exemplary embodiment, the difference between the wavelengths corresponding to the peaks of the photoluminescence spectrum curves of the two green doping materials is greater than or equal to 1 nm and less than or equal to 10 nm; the difference between the wavelengths corresponding to the peaks of the photoluminescence spectrum curves of the two blue doping materials is greater than or equal to 1 nm and less than or equal to 10 nm.

[0008] In an exemplary embodiment, the two blue doping materials include a first blue doping material and a second blue doping material; wherein, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the first blue doping material is greater than or equal to 452nm and less than or equal to 458nm, and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the second blue doping material is greater than or equal to 458nm and less than or equal to 464nm.

[0009] In an exemplary embodiment, the material of the blue light-emitting layer includes two blue doping materials, including: the blue light-emitting device includes a blue light-emitting layer, and the first blue doping material and the second blue doping material are both doped in the blue light-emitting layer.

[0010] In an exemplary embodiment, the thickness of the blue light-emitting layer is greater than or equal to 20 nm and less than or equal to 30 nm.

[0011] In an exemplary embodiment, the material of the blue light-emitting layer includes two blue doping materials, including: the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer arranged in sequence along a direction away from the substrate; one of the first blue doping material and the second blue doping material is doped in the first blue light-emitting layer, and the other is doped in the second blue light-emitting layer.

[0012] In an exemplary embodiment, the thickness of the first blue light-emitting layer is greater than or equal to 15 nm and less than or equal to 25 nm, and the thickness of the second blue light-emitting layer is greater than or equal to 15 nm and less than or equal to 25 nm.

[0013] In an exemplary embodiment, the two green doping materials include a first green doping material and a second green doping material; wherein the peak value of the photoluminescence spectrum curve of the first green doping material is greater than or equal to 520nm and less than or equal to 530nm, and the peak value of the photoluminescence spectrum curve of the second green doping material is greater than or equal to 530nm and less than or equal to 540nm.

[0014] In an exemplary embodiment, when the blue light-emitting device includes a blue light-emitting layer, the material of the green light-emitting layer includes two green doping materials, including: the green light-emitting device includes a green light-emitting layer, and the first green doping material and the second green doping material are both doped in the green light-emitting layer.

[0015] In an exemplary embodiment, the thickness of the green light-emitting layer is greater than or equal to 25 nm and less than or equal to 35 nm.

[0016] In an exemplary embodiment, when the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer, the material of the green light-emitting layer includes two green doping materials, including: the green light-emitting device includes a first green light-emitting layer and a second green light-emitting layer arranged in sequence along a direction away from the substrate; one of the first green doping material and the second green doping material is doped in the first green light-emitting layer, and the other is doped in the second green light-emitting layer.

[0017] In an exemplary embodiment, the thickness of the first green light-emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm; the thickness of the second green light-emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm.

[0018] In an exemplary embodiment, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the red doping material is greater than or equal to 622 nm and less than or equal to 632 nm.

[0019] In an exemplary embodiment, when the green light-emitting device includes a green light-emitting layer and the blue light-emitting device includes a blue light-emitting layer, the red light-emitting device includes a red light-emitting layer; when the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer, and the green light-emitting device includes a first green light-emitting layer and a second green light-emitting layer, the red light-emitting device includes a first red light-emitting layer and a second red light-emitting layer arranged sequentially in a direction away from the substrate.

[0020] On the other hand, an embodiment of the present disclosure provides a display device including the display substrate as described above.

[0021] The display substrate provided by the embodiment of the present disclosure, when the brightness decay rates of red light and green light are close as the viewing angle increases, and the brightness decay rates of red light and green light are slower than those of blue light, by setting the material of the blue light-emitting layer of the display substrate to include two blue doping materials, the brightness decay rate of the blue light of the display substrate as the viewing angle increases is slowed down, so that the brightness decay rates of the red light, green light and blue light of the display substrate as the viewing angle increases are close, which greatly improves the color deviation of the display substrate. When the brightness decay rates of green light and blue light are close as the viewing angle increases, and the brightness decay rate of red light is slower than those of green light and blue light, by setting the material of the blue light-emitting layer of the display substrate to include two blue doping materials, and the material of the green light-emitting layer to include two green doping materials, the brightness decay rates of the green light and blue light of the display substrate as the viewing angle increases are slowed down, so that the brightness decay rates of the red light, green light and blue light of the display substrate as the viewing angle increases are close, which greatly improves the color deviation of the display substrate. The problem of color deviation of display products at different viewing angles is solved.

[0022] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings.

[0023] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0025] Figure 1 is a structural schematic diagram of a display device;

[0026] Figure 2 It is a schematic diagram of a planar structure of a display substrate;

[0027] Figure 3 is a schematic diagram of an equivalent circuit of a pixel driving circuit;

[0028] Figure 4 A schematic diagram of a cross-sectional structure of a display substrate;

[0029] Figure 5 A graph showing the attenuation of the brightness of light of different colors in a substrate as the viewing angle changes;

[0030] Figure 6 is a curve diagram showing the attenuation of the brightness of light of different colors in another display substrate as the viewing angle changes;

[0031] Figure 7 is a schematic diagram showing a cross-sectional structure of a substrate in an exemplary embodiment;

[0032] Figure 8 is a photoluminescence spectrum of two blue doping materials in an exemplary embodiment;

[0033] Fig. 9 is a photoluminescence spectrum of two green doping materials in an exemplary embodiment;

[0034] Fig.10 is a photoluminescence spectrum of a red dopant material in an exemplary embodiment;

[0035] Fig.11 In an exemplary embodiment Figure 7 The graph showing the brightness of different colors of light on the display substrate attenuates with viewing angle;

[0036] Fig.12FIG. 4 is a schematic diagram showing a cross-sectional structure of a substrate in yet another exemplary embodiment. DETAILED DESCRIPTION

[0037] The present disclosure describes multiple embodiments, but the description is exemplary rather than restrictive, and it is apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present disclosure. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0038] The present disclosure includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in the present disclosure may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present disclosure may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0039] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be appreciated by those of ordinary skill in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art can easily understand that these orders can be changed and still remain within the spirit and scope of the disclosed embodiments.

[0040] In the drawings, the size of one or more components, the thickness of a layer, or an area is sometimes exaggerated for the sake of clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to the size, and the shape and size of one or more components in the drawings do not reflect the true proportion. In addition, the drawings schematically show ideal examples, and one embodiment of the present disclosure is not limited to the shapes or values ​​shown in the drawings.

[0041] The ordinal numbers such as "first", "second", and "third" in this specification are provided to avoid confusion of constituent elements, and are not intended to limit the quantity. The "plurality" in this disclosure means two or more.

[0042] 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" and the like 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 orientation of the constituent elements being described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the circumstances.

[0043] 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 meanings of the above terms in this disclosure can be understood according to the circumstances.

[0044] 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 electrical signals between 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.

[0045] 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°.

[0046] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0047] Figure 1 FIG. 1 is a schematic diagram of the structure of a display device. Figure 1As shown, the display device may include: a scan signal driver, a data signal driver, a light emitting signal driver, a display substrate, a first power supply unit, a second power supply unit, and an initial power supply unit. In some exemplary embodiments, the display substrate includes at least a plurality of scan signal lines (S(1) to S(N)), a plurality of data signal lines (D(1) to D(M)), and a plurality of light emitting signal lines (EM(1) to EM(N)). The scan signal driver is configured to sequentially provide scan signals to the plurality of scan signal lines (S(1) to S(N)), the data signal driver is configured to provide data signals to the plurality of data signal lines (D(1) to D(M)), and the light emitting signal driver is configured to sequentially provide light emitting control signals to the plurality of light emitting signal lines (EM(1) to EM(N)). In some exemplary embodiments, the plurality of scan signal lines and the plurality of light emitting signal lines extend in a horizontal direction, and the plurality of data signal lines extend in a vertical direction. The display substrate includes a plurality of sub-pixels, and one sub-pixel includes a pixel driving circuit and a light emitting device. The pixel driving circuit is connected to the scanning signal line, the light emitting control line and the data signal line. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line under the control of the scanning signal line and the light emitting signal line, and output the corresponding current to the light emitting device. The light emitting device is connected to the pixel driving circuit, and the light emitting device is configured to emit light of corresponding brightness in response to the current output by the pixel driving circuit. The first power supply unit, the second power supply unit and the initial power supply unit are respectively configured to provide the first power supply voltage, the second power supply voltage and the initial power supply voltage to the pixel driving circuit through the first power supply line, the second power supply line and the initial signal line.

[0048] Figure 2 FIG. 1 is a schematic diagram of a planar structure of a display substrate. Figure 2 As shown, the display area 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. 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. In some exemplary embodiments, the pixel unit P may include a red (R) sub-pixel, a green (G) sub-pixel, and a blue (B) sub-pixel, or may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white (W) sub-pixel, which is not limited in the present disclosure. In some exemplary embodiments, the shape of the sub-pixel in the pixel unit may be a rectangle, a rhombus, a pentagon, or a hexagon. When the pixel unit includes three sub-pixels, the three sub-pixels may be arranged in a horizontal parallel, vertical parallel, or a triangle pattern, and when the pixel unit includes four sub-pixels, the four sub-pixels may be arranged in a horizontal parallel, vertical parallel, or square pattern. However, the present disclosure is not limited in this regard.

[0049] In some exemplary embodiments, the pixel driving circuit may be a 3T1C, 4T1C, 5T1C, 5T2C, 6T1C, or 7T1C structure. Figure 3 is an equivalent circuit diagram of a pixel driving circuit. Figure 3 As shown, the pixel driving circuit may include 7 switch transistors (first transistor T1 to seventh transistor T7), 1 storage capacitor C and 8 signal lines (data signal line DATA, first scan signal line S1, second scan signal line S2, first initial signal line INIT1, second initial signal line INIT2, first power line VSS, second power line VDD and light emitting signal line EM). Among them, the first initial signal line INIT1 and the second initial signal line INIT2 may be the same signal line.

[0050] In some exemplary embodiments, the control electrode of the first transistor T1 is connected to the second scan signal line S2, the first electrode of the first transistor T1 is connected to the first initial signal line INIT1, and the second electrode of the first transistor T1 is connected to the second node N2. The control electrode of the second transistor T2 is connected to the first scan signal line S1, the first electrode of the second transistor T2 is connected to the second node N2, and the second electrode of the second transistor T2 is connected to the third node N3. The control electrode of the third transistor T3 is connected to the second node N2, the first electrode of the third transistor T3 is connected to the first node N1, and the second electrode of the third transistor T3 is connected to the third node N3. The control electrode of the fourth transistor T4 is connected to the first scan signal line S1, the first electrode of the fourth transistor T4 is connected to the data signal line DATA, and the second electrode of the fourth transistor T4 is connected to the first node N1. The control electrode of the fifth transistor T5 is connected to the light emitting signal line EM, the first electrode of the fifth transistor T5 is connected to the second power supply line VDD, and the second electrode of the fifth transistor T5 is connected to the first node N1. The control electrode of the sixth transistor T6 is connected to the light emitting signal line EM, the first electrode of the sixth transistor T6 is connected to the third node N3, and the second electrode of the sixth transistor T6 is connected to the first electrode of the light emitting device. The control electrode of the seventh transistor T7 is connected to the first scanning signal line S1, the first electrode of the seventh transistor T7 is connected to the second initial signal line INIT2, and the second electrode of the seventh transistor T7 is connected to the first electrode of the light emitting device. The first end of the storage capacitor C is connected to the second power supply line VDD, and the second end of the storage capacitor C is connected to the second node N2.

[0051] In some exemplary embodiments, the first transistor T1 to the seventh transistor T7 may be a P-type transistor, or may be an N-type transistor. Using the same type of transistors in the pixel driving circuit can simplify the process flow, reduce the process difficulty of the display panel, and improve the yield of the product. In some possible implementations, the first transistor T1 to the seventh transistor T7 may include a P-type transistor and an N-type transistor.

[0052] In some exemplary embodiments, the second electrode of the light-emitting device is connected to the first power line VSS. The signal of the first power line VSS is a low-level signal, and the signal of the second power line VDD is a continuously provided high-level signal. The first scan signal line S1 is a scan signal line in the pixel drive circuit of the current display row, and the second scan signal line S2 is a scan signal line in the pixel drive circuit of the previous display row, that is, for the nth display row, the first scan signal line S1 is S(n), and the second scan signal line S2 is S(n-1). The second scan signal line S2 of the current display row is the same as the first scan signal line S1 in the pixel drive circuit of the previous display row, which can reduce the signal lines of the display panel and realize a narrow frame of the display panel.

[0053] Figure 4 FIG. 1 is a schematic diagram of a cross-sectional structure of a display substrate, illustrating the structure of three sub-pixels of the display substrate. Figure 4 As shown, on a plane perpendicular to the display substrate, the display substrate may include a driving circuit layer 102 disposed on a substrate 101, a light emitting device 103 disposed on a side of the driving circuit layer 102 away from the substrate 101, and an encapsulation layer 104 disposed on a side of the light emitting device 103 away from the substrate 101. In some possible implementations, the display substrate may include other film layers, such as spacers, etc., which are not limited in the present disclosure.

[0054] In some exemplary embodiments, the substrate 101 may be a flexible substrate or a rigid substrate. The flexible substrate may include a first flexible material layer, a first inorganic material layer, a semiconductor layer, a second flexible material layer, and a second inorganic material layer stacked together. The materials of the first flexible material layer and the second flexible material layer may be polyimide (PI), polyethylene terephthalate (PET), or a surface-treated polymer soft film, etc. The materials of the first inorganic material layer and the second inorganic material layer may be silicon nitride (SiNx) or silicon oxide (SiOx), etc., to improve the water and oxygen resistance of the substrate, and the material of the semiconductor layer may be amorphous silicon (a-Si).

[0055] In some exemplary embodiments, the driving circuit layer 102 of each sub-pixel may include a plurality of transistors and storage capacitors constituting a pixel driving circuit. Figure 4In the example, each sub-pixel includes a driving transistor and a storage capacitor. In some possible implementations, the driving circuit layer 102 of each sub-pixel may include: a first insulating layer 201 disposed on a substrate; an active layer disposed on the first insulating layer; a second insulating layer 202 covering the active layer; a gate electrode and a first capacitor electrode disposed on the second insulating layer 202; a third insulating layer 203 covering the gate electrode and the first capacitor electrode; a second capacitor electrode disposed on the third insulating layer 203; a fourth insulating layer 204 covering the second capacitor electrode, and vias are provided on the second insulating layer 202, the third insulating layer 203 and the fourth insulating layer 204, and the vias expose the active layer; a source electrode and a drain electrode disposed on the fourth insulating layer 204, and the source electrode and the drain electrode are connected to the active layer through the vias respectively; and a flat layer 205 covering the above structure, and vias are provided on the flat layer 205, and the vias expose the drain electrode. The active layer, the gate electrode, the source electrode and the drain electrode constitute the driving transistor 210, and the first capacitor electrode and the second capacitor electrode constitute the storage capacitor 211.

[0056] In some exemplary embodiments, the light emitting device 103 may include an anode 301, a pixel definition layer 302, an organic light emitting layer 303, and a cathode 304. The anode 301 is disposed on the planar layer 205, and is connected to the drain electrode of the driving transistor 210 through a via hole provided on the planar layer 205; the pixel definition layer 302 is disposed on the anode 301 and the planar layer 205, and a pixel opening is provided on the pixel definition layer 302, and the pixel opening exposes the anode 301; the organic light emitting layer 303 is at least partially disposed in the pixel opening, and the organic light emitting layer 303 is connected to the anode 301; the cathode 304 is disposed on the organic light emitting layer 303, and the cathode 304 is connected to the organic light emitting layer 303; the organic light emitting layer 303 emits light of corresponding colors under the drive of the anode 301 and the cathode 304.

[0057] In some exemplary embodiments, the encapsulation layer 104 may include a stacked first encapsulation layer 401, a second encapsulation layer 402, and a third encapsulation layer 403. The first encapsulation layer 401 and the third encapsulation layer 403 may be made of inorganic materials, the second encapsulation layer 402 may be made of organic materials, and the second encapsulation layer 402 is disposed between the first encapsulation layer 401 and the third encapsulation layer 403, so as to ensure that external water vapor cannot enter the light-emitting device 103.

[0058] In some exemplary embodiments, the organic light-emitting layer of the light-emitting device may include a light-emitting layer (EML, Emitting Layer), and one or more film layers including a hole injection layer (HIL, Hole Injection Layer), a hole transport layer (HTL, Hole Transport Layer), a hole blocking layer (HBL, Hole Block Layer), an electron blocking layer (EBL, Electron Block Layer), an electron injection layer (EIL, Electron Injection Layer), and an electron transport layer (ETL, Electron Transport Layer). Under the voltage drive of the anode and the cathode, the light-emitting characteristics of the organic material are used to emit light according to the required grayscale.

[0059] In some exemplary embodiments, the light-emitting layers of OLED light-emitting devices of different colors are different. For example, a red light-emitting device includes a red light-emitting layer, a green light-emitting device includes a green light-emitting layer, and a blue light-emitting device includes a blue light-emitting layer. In order to reduce the process difficulty and improve the yield, the hole injection layer and the hole transport layer on one side of the light-emitting layer can use a common layer, and the electron injection layer and the electron transport layer on the other side of the light-emitting layer can use a common layer. In some exemplary embodiments, any one or more layers of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer can be made by a single process (a single evaporation process or a single inkjet printing process), but isolation is achieved by means of a surface step difference of the formed film layer or by surface treatment. For example, any one or more layers of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer corresponding to adjacent sub-pixels can be isolated. In some exemplary embodiments, the organic light-emitting layer can be formed by evaporation using a fine metal mask (FMM, Fine Metal Mask) or an open mask (Open Mask), or by inkjet technology.

[0060] In a display substrate, light-emitting devices of different colors have the same film structure. Since the spectral half-width (FWHM) of light of different colors is different, the brightness of light of different colors attenuates at different rates with viewing angle, and users will feel obvious color shift when viewing the displayed image.

[0061] Figure 5 FIG. 1 is a graph showing the attenuation of the brightness of light of different colors in a display substrate as the viewing angle changes, taking a display substrate including light-emitting devices of three colors, red, green and blue, as an example. Figure 5As shown, the horizontal axis represents the viewing angle in degrees, and the vertical axis represents the percentage of brightness. When the screen is viewed from the front (i.e., the viewing angle between the user and the display substrate is 0 degrees), the brightness of the screen is set to 100%. As the viewing angle increases, the brightness of different colors of light gradually decreases. Figure 5 Among them, L1 represents red light, L2 represents green light, and L3 represents blue light. Figure 5 It can be found that as the viewing angle increases, the brightness decay rates of green light and blue light are close, while the brightness decay rate of red light is slower than that of green light and blue light. This asynchrony in brightness decay leads to color deviation of the display substrate.

[0062] Figure 6 is another curve diagram showing the attenuation of the brightness of light of different colors in a display substrate as the viewing angle decreases. Figure 6 and Figure 5 The only difference is that the brightness of different colors of light changes differently as the viewing angle increases. Figure 6 As shown, in some embodiments, as the viewing angle increases, the brightness decay rates of red light and green light may be close, and the brightness decay rates of red light and green light are slower than that of blue light. This situation may also cause color deviation of the display substrate.

[0063] The embodiment of the present disclosure provides a display substrate, comprising: a substrate and a plurality of light-emitting devices arranged on the substrate, the plurality of light-emitting devices comprising a red light-emitting device, a green light-emitting device and a blue light-emitting device, the red light-emitting device comprising a red light-emitting layer, the green light-emitting device comprising a green light-emitting layer, and the blue light-emitting device comprising a blue light-emitting layer; the material of the red light-emitting layer comprises a red doping material; the material of the green light-emitting layer comprises a green doping material, and the material of the blue light-emitting layer comprises two blue doping materials; or, the material of the green light-emitting layer comprises two green doping materials, and the material of the blue light-emitting layer comprises two blue doping materials; wherein the peaks of the photoluminescence spectrum curves of the two green doping materials correspond to different wavelengths, and the peaks of the photoluminescence spectrum curves of the two blue doping materials correspond to different wavelengths.

[0064] The display substrate provided by the embodiment of the present disclosure, when the brightness decay rates of red light and green light are close with the increase of viewing angle, and the brightness decay rates of red light and green light are slower than that of blue light, by setting the material of the blue light emitting layer of the display substrate to include two blue doping materials, the brightness decay rate of the blue light of the display substrate is slowed down with the increase of viewing angle, so that the brightness decay rates of the red light, green light and blue light of the display substrate are close with the increase of viewing angle, which greatly improves the color deviation of the display substrate. When the brightness decay rates of green light and blue light are close with the increase of viewing angle, and the brightness decay rate of red light is slower than that of green light and blue light, by setting the material of the blue light emitting layer of the display substrate to include two blue doping materials, and the material of the green light emitting layer to include two green doping materials, the brightness decay rate of the green light and blue light of the display substrate is slowed down with the increase of viewing angle, so that the brightness decay rates of the red light, green light and blue light of the display substrate are close with the increase of viewing angle, which greatly improves the color deviation of the display substrate.

[0065] Figure 7 is a schematic diagram showing a cross-sectional structure of a substrate in an exemplary embodiment, and Figure 4 compared to, Figure 7 The structure of the light emitting device 103 is shown in detail in FIG. 1 , such as the structure of the driving circuit layer 102 and the packaging layer 104 and other film layers, which can be referred to in FIG. Figure 4 The description will not be repeated here.

[0066] like Figure 7 As shown, in the direction away from the substrate 101, the organic light-emitting layer 303 of the light-emitting device may include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer and an electron transport layer 14 arranged in sequence. The light-emitting device 103 may also include a light extraction layer 305 arranged on the side of the cathode 304 away from the substrate 101.

[0067] In an exemplary embodiment, the hole injection layer may be a common layer, the hole transport layer may be a common layer, and the hole injection layer and the hole transport layer sequentially cover the anode 301 and the pixel definition layer 302 on a side away from the substrate 101. Figure 7 The hole injection layer and the hole transport layer are indicated by reference numeral 11. The material of the hole transport layer may include any one or more of the following: N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4-4′-diamine (NPB), triphenyldiamine derivative (TPD), TPTE, 1,3,5-tri(N-3-methylphenyl-N-phenylamino)benzene (TDAB). Other types of hole transport materials may be selected as needed, and the present disclosure is not limited thereto.

[0068] In an exemplary embodiment, the material of the hole injection layer can be obtained by doping the hole injection material in the material of the hole transport layer, so that there is a good transition between the hole injection layer and the hole transport layer. Among them, the doping ratio of the hole injection material can be greater than or equal to 1% and less than or equal to 50%. The hole injection material may include any one or more of the following: NDP series P-type doping materials (including NDP-2, NDP-9, etc.), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethylbenzene (F4-TCNQ), tris (4-bromophenyl) ammonium hexachloroantimonate (TBAHA). Other types of hole injection materials and hole transport materials can be selected as needed, and the present disclosure is not limited to this.

[0069] In an exemplary embodiment, the thickness of the hole injection layer may be greater than or equal to 1 nm and less than or equal to 10 nm. In the disclosed embodiment, the thickness of the "film layer A" is the distance between the surface of the "film layer A" close to the substrate 101 and the surface of the "film layer A" away from the substrate 101 in a direction perpendicular to the substrate 101.

[0070] In an exemplary embodiment, the hole mobility in the electron blocking layer is greater than the electron mobility. The highest occupied molecular orbital (HOMO) energy level of the electron blocking layer HOMO EBL Lower than the HOMO level of the hole transport layer HOMO HTL For example, HOMO EBL and HOMO HTL The difference between them can be about 0.2 eV. The lowest unoccupied molecular orbital (LUMO) energy level of the electron blocking layer LUMO EBL Higher than the LUMO level of the luminescent layerLUMO EML For example, LUMO EBL and LUMO EML The difference between can be about 0.2 eV.

[0071] In an exemplary embodiment, the electron blocking layer includes a red electron blocking layer 121, a green electron blocking layer 122, and a blue electron blocking layer 123. The thickness of the red electron blocking layer 121 may be greater than the thickness of the green electron blocking layer 122, and the thickness of the green electron blocking layer 122 may be greater than the thickness of the blue electron blocking layer 123. The red electron blocking layer 121, the green electron blocking layer 122, and the blue electron blocking layer 123 may be prepared by vacuum evaporation process using red, green, and blue high-definition metal masks, respectively, and the present disclosure is not limited thereto.

[0072] In exemplary embodiments, the material of the electron blocking layer may include any one or more of 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3(biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-4H-1,2,4-triazole, which is not limited in the present disclosure.

[0073] In an exemplary embodiment, the thickness of the electron blocking layer may be greater than or equal to 5 nm and less than or equal to 100 nm. The thickness of the red electron blocking layer 121 , the green electron blocking layer 122 , and the blue electron blocking layer 123 may be set as needed, which is not limited in the present disclosure.

[0074] In an exemplary embodiment, the light-emitting layer may include a red light-emitting layer 131, a green light-emitting layer 132, and a blue light-emitting layer 133. The red light-emitting layer 131, the green light-emitting layer 132, and the blue light-emitting layer 133 may be prepared by a vacuum evaporation process using red, green, and blue high-precision metal masks, respectively. The present disclosure does not limit this.

[0075] In an exemplary embodiment, the material of the blue light-emitting layer 133 may include two blue doping materials and one or two blue main materials, and the peaks of the photoluminescence spectrum curves of the two blue doping materials correspond to different wavelengths. The hole mobility of the blue main material is higher than the electron mobility, and the blue main material may include any one or more of the following: 3-tert-butyl-9,10-di(2-naphthalene)anthracene, 2-methyl-9,10-bis(naphthalene-2-yl)anthracene, (2,2-diphenylethylene)-1,1c biphenyl, and the present disclosure is not limited to this. By setting the material of the blue light-emitting layer 133 to include two blue doping materials, and the peaks of the photoluminescence spectrum curves of the two blue doping materials correspond to different wavelengths, it is helpful to reduce the brightness decay rate of blue light as the viewing angle increases, so that the brightness decay rates of the red light, green light and blue light of the display substrate as the viewing angle increases are close, and the color shift phenomenon of the display substrate is reduced. When the brightness decay rates of red light and green light are close to each other as the viewing angle increases, and the brightness decay rates of red light and green light are slower than that of blue light, the color deviation of the display substrate can be improved only by adjusting the material of the blue light-emitting layer 133. This method does not add new preparation steps, helps save costs, and is suitable for popularization and use.

[0076] In an exemplary embodiment, the blue doping material may include any one or more of the following: 4,4'-bis(9-ethyl-3-carbazole vinyl)-1,1'-biphenyl, 1,1,4,4-tetraphenylbutadiene, 4'-(4-(diphenylamino)phenyl)-5'-phenyl-[1,1':2',1"-terphenyl]-4-nitrile, 1-4-di-[4-(N,N-diphenyl)amino]phenylbenzene, etc. Other suitable blue doping materials can be selected as needed, and the present disclosure is not limited to this.

[0077] Figure 8 FIG. 4 is a graph showing photoluminescence spectra of two blue doping materials in an exemplary embodiment. Figure 8 The horizontal axis represents wavelength in nm, and the vertical axis represents intensity. The difference D1 between the wavelength corresponding to the peak of the photoluminescence spectrum curve of the first blue doping material B1 and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the second blue doping material B2 may be greater than or equal to 1 nm and less than or equal to 10 nm. For example, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the first blue doping material B1 may be greater than or equal to 452 nm and less than or equal to 458 nm, and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the second blue doping material B2 may be greater than or equal to 458 nm and less than or equal to 464 nm.

[0078] In exemplary embodiments, the thickness of the blue light emitting layer 133 may be greater than or equal to 20 nm and less than or equal to 30 nm.

[0079] In an exemplary embodiment, the material of the green light-emitting layer 132 may include two green doping materials and one or two green main materials, and the peak ranges of the photoluminescence spectrum curves of the two green doping materials are different. A suitable green main material can be selected as needed, and the green doping material may include an iridium or platinum compound, which is not limited by the present disclosure. By setting the material of the green light-emitting layer 132 to include two green doping materials, and the peaks of the photoluminescence spectrum curves of the two green doping materials are different, it is helpful to reduce the brightness decay rate of green light as the viewing angle increases, so that the brightness decay rates of the red light, green light and blue light of the display substrate as the viewing angle increases are close, and the color shift phenomenon of the display substrate is reduced. In the case where the brightness decay rates of green light and blue light are closer as the viewing angle increases, and the brightness decay rate of red light is slower than that of green light and blue light, the color shift of the display substrate can be improved by adjusting the materials of the green light-emitting layer 132 and the blue light-emitting layer 133. This method does not add new preparation steps, helps save costs, and is suitable for promotion and use.

[0080] Fig. 9 FIG. 4 is a graph showing photoluminescence spectra of two green doping materials in an exemplary embodiment. Fig. 9The horizontal axis represents wavelength in nm, and the vertical axis represents intensity. The difference D2 between the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the first green doping material G1 and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the second green doping material G2 may be greater than or equal to 1 nm and less than or equal to 10 nm. For example, the peak value of the photoluminescence spectrum curve of the first green doping material G1 may be greater than or equal to 520 nm and less than or equal to 530 nm, and the peak value of the photoluminescence spectrum curve of the second green doping material G2 may be greater than or equal to 530 nm and less than or equal to 540 nm.

[0081] In exemplary embodiments, the thickness of the green light emitting layer 132 may be greater than or equal to 25 nm and less than or equal to 35 nm.

[0082] In an exemplary embodiment, the material of the red light-emitting layer 131 may include a red doping material and one or two red host materials. The red host material may be, for example, 4,4′4″-tri(N-carbazole)triphenylamine, and the red doping material may include an iridium compound or a platinum compound. For example, the red doping material may include one or more of the following materials: bis[2-(2′-benzo-4,5-α-thiophene)pyridine]acetylacetonate iridium, tri(1-phenyl-isoquinoline)iridium(III); tri[1-phenylisoquinoline-C2,N]iridium, which is not limited in the present disclosure.

[0083] Fig.10 FIG. 4 is a graph showing a photoluminescence spectrum of a red dopant material in an exemplary embodiment. Fig.10 The horizontal axis represents the wavelength in nm, and the vertical axis represents the intensity. The peak value of the photoluminescence spectrum curve of the red doping material R1 may be greater than or equal to 622 nm and less than or equal to 632 nm.

[0084] In exemplary embodiments, the thickness of the red light emitting layer 131 may be greater than or equal to 30 nm and less than or equal to 50 nm.

[0085] In an exemplary embodiment, the material of the electron transport layer 14 may include one or more of the following materials: 2-(4-biphenyl)-5-phenyloxadiazole (PBD), 2,5-di(1-naphthyl)-1,3,5-oxadiazole (BND), 2,4,6-triphenoxy-1,3,5-triazine (TRZ), which is not limited in the present disclosure.

[0086] In exemplary embodiments, the thickness of the electron transport layer 14 may be greater than or equal to 10 nm and less than or equal to 40 nm.

[0087] In an exemplary embodiment, the material of the cathode layer 304 may include any one of the following metal materials: Mg, Ag, Al, Li, K, Ca, or may include alloy materials of the above metal materials, for example: Mg x Ag (1-x) , Li x Al (1-x) , Li x Ca (1-x) , Li x Ag (1-x) The present disclosure does not limit this.

[0088] In an exemplary embodiment, the thickness of cathode 304 may be greater than or equal to 10 nm and less than or equal to 20 nm.

[0089] In an exemplary embodiment, the material of the light extraction layer 305 may be a high refractive index material. For example, under light with a wavelength ranging from 450 nanometers to 780 nanometers, the refractive index of the light extraction layer 305 may be greater than 2.0, that is, n>2.0@450-780nm. The material of the light extraction layer 305 may be a high transmittance material. For example, under light with a wavelength ranging from 450 nanometers to 780 nanometers, the light absorption coefficient k of the light extraction layer 305 may be less than or equal to 0.01, that is, k≤0.01@450-780nm.

[0090] In an exemplary embodiment, the material of the light extraction layer 305 may include any one or more of the following: N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4-4′-diamine (NPB), a triphenyldiamine derivative (TPD), N,N'-diphenyl-N,N'-di(4'-(N,N-di(1-naphthyl)-amino)-4-biphenyl)-benzidine (TPTE), 1,3,5-tri(N-3-methylphenyl-N-phenylamino)benzene (TDAB), copper phthalocyanine (CuPc), and the like.

[0091] In example embodiments, the thickness of the light extraction layer 305 may be greater than or equal to 50 nm and less than or equal to 100 nm.

[0092] Fig.11 In an exemplary embodiment Figure 7 The graph shown is a graph showing the attenuation of the brightness of different color lights of the display substrate as the viewing angle changes. Fig.11 The horizontal axis represents the viewing angle in degrees, and the vertical axis represents the percentage of brightness. L1 represents red light, L2 represents green light, and L3 represents blue light. Fig.11 It can be seen that Figure 5 or Figure 6 compared to, Fig.11The speed at which the brightness of different colors of light decays with viewing angle is similar, indicating that the Figure 7 The solution can effectively solve the color deviation problem of the display substrate.

[0093] Fig.12 is a schematic diagram showing a cross-sectional structure of a substrate in another exemplary embodiment, Fig.12 and Figure 7 The difference is that the structure of the organic light emitting layer 303 is different, and the rest of the structure can refer to the above Figure 7 The description will not be repeated here.

[0094] like Fig.12 As shown, in the direction away from the substrate 101, the organic light-emitting layer 303 of the light-emitting device may include a hole injection layer, a first hole transport layer, a first electron blocking layer, a first light-emitting layer, a first electron transport layer, a charge generation layer, a second hole transport layer, a second electron blocking layer, a second light-emitting layer and a second electron transport layer which are arranged in sequence.

[0095] In an exemplary embodiment, the hole injection layer may be a common layer, the first hole transport layer may be a common layer, and the hole injection layer and the first hole transport layer sequentially cover the anode 301 and the pixel definition layer 302 on a side away from the substrate 101. Fig.12 The hole injection layer and the first hole transport layer are indicated by reference numeral 21. The material and thickness of the hole injection layer and the material of the first hole transport layer in this embodiment can refer to the Figure 7 The description of the hole injection layer and the hole transport layer will not be repeated here.

[0096] In an exemplary embodiment, the first electron blocking layer may include a first red electron blocking layer 221, a first green electron blocking layer 222, and a first blue electron blocking layer 223. The thickness of the first red electron blocking layer 121 may be greater than the thickness of the first green electron blocking layer 122, and the thickness of the first green electron blocking layer 122 may be greater than the thickness of the first blue electron blocking layer 123. The thickness, material, relationship with the HOMO energy level of the first hole transport layer, and relationship with the LUMO energy level of the first light-emitting layer of the first electron blocking layer may refer to the description of Figure 7 The relevant description of the electron blocking layer will not be repeated here.

[0097] In example embodiments, the first light emitting layer may include a first red light emitting layer 231 , a first green light emitting layer 232 , and a first blue light emitting layer 233 .

[0098] In an exemplary embodiment, the material of the first blue light emitting layer 233 may include a blue doping material and one or two blue host materials. The types of the blue doping material and the blue host material may refer to the Figure 7The description of the blue light emitting layer 133 is omitted here. In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233 may be greater than or equal to 452 nm and less than or equal to 458 nm.

[0099] In exemplary embodiments, the thickness of the first blue light emitting layer 233 may be greater than or equal to 15 nm and less than or equal to 25 nm.

[0100] In an exemplary embodiment, the material of the first green light emitting layer 232 may include a green doping material and one or two green host materials. The types of the green doping material and the green host material may refer to the description of Figure 7 The description of the green light emitting layer 132 is omitted here. In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light emitting layer 232 may be greater than or equal to 520 nm and less than or equal to 530 nm.

[0101] In exemplary embodiments, the thickness of the first green light emitting layer 232 may be greater than or equal to 20 nm and less than or equal to 35 nm.

[0102] In an exemplary embodiment, the material and thickness of the first red light emitting layer 231 and the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the red doping material can be referred to as Figure 7 The description of the red light emitting layer 131 is not repeated here.

[0103] In an exemplary embodiment, the material of the first electron transport layer 24 may be Figure 7 The materials of the electron transport layer 14 listed in the above may also be 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene and the like, and the present disclosure does not limit this.

[0104] In exemplary embodiments, the thickness of the first electron transport layer 24 may be greater than or equal to 10 nm and less than or equal to 30 nm.

[0105] In an exemplary embodiment, the charge generation layer (CGL) 25 may include a first charge generation layer and a second charge generation layer sequentially disposed away from the substrate 101. The material of the first charge generation layer may refer to the aforementioned description of the first hole injection layer material, which will not be repeated here. The material of the second charge generation layer may include an electron transport layer material doped with a metal material, and the electron transport layer material may be selected as needed. The doped metal material may include Li, Yb, etc., may be doped with one or more metal materials, or may be doped with an alloy of multiple metal materials, and the present disclosure is not limited to this.

[0106] In an exemplary embodiment, the thickness of the second charge generation layer may be greater than or equal to 5 nm and less than or equal to 10 nm, and the thickness of the charge generation layer 25 may be set as needed, which is not limited in the present disclosure.

[0107] In an exemplary embodiment, the thickness of the first hole transport layer may be greater than the thickness of the second hole transport layer 26, and the thickness of the second hole transport layer 26 and the thickness of the first hole transport layer may be set as needed, and the present disclosure is not limited thereto. The material of the second hole transport layer 26 may refer to the aforementioned description of the first hole transport layer, for example, the same as the material of the first hole transport layer, and will not be repeated here.

[0108] In an exemplary embodiment, the second electron blocking layer may include a second red electron blocking layer 271, a second green electron blocking layer 272, and a second blue electron blocking layer 273. The thickness of the second red electron blocking layer 271 may be greater than the thickness of the second green electron blocking layer 272, and the thickness of the second green electron blocking layer 272 may be greater than the thickness of the second blue electron blocking layer 273. The thickness, material, relationship with the HOMO energy level of the second hole transport layer, and relationship with the LUMO energy level of the second light-emitting layer of the second electron blocking layer may refer to the above description of the first electron blocking layer, and will not be repeated here.

[0109] In example embodiments, the second light emitting layer may include a second red light emitting layer 281 , a second green light emitting layer 282 , and a second blue light emitting layer 283 .

[0110] In an exemplary embodiment, the material of the second blue light-emitting layer 283 may include a blue dopant material and one or two blue main materials. The types of the blue dopant material and the blue main material can refer to the aforementioned description of the first blue light-emitting layer 233, and the thickness of the second blue light-emitting layer 283 can refer to the aforementioned description of the first blue light-emitting layer 233, which will not be repeated here.

[0111] In an exemplary embodiment, the difference between the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283 and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233 may be greater than or equal to 1 nm and less than or equal to 10 nm. In this embodiment, by setting the blue doping material in the second blue light emitting layer 283 to be different from the blue doping material in the first blue light emitting layer 233, the difference between the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283 and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233 may be greater than or equal to 1 nm and less than or equal to 10 nm, which helps to reduce the brightness decay rate of blue light with an increase in viewing angle, so that the brightness decay rates of red light, green light and blue light of the display substrate with an increase in viewing angle are close, and the color shift phenomenon of the display substrate is reduced. When the brightness decay rates of red light and green light are close to each other as the viewing angle increases, and the brightness decay rates of red light and green light are slower than that of blue light, the color deviation of the display substrate can be improved only by adjusting the materials of the first blue light-emitting layer 233 and the second blue light-emitting layer 283. This method does not add new preparation steps, helps save costs, and is suitable for popularization and use.

[0112] In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283 may be greater than or equal to 458 nm and less than or equal to 464 nm. This embodiment is illustrated by taking the example that the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283 is greater than or equal to the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233. In other embodiments, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233 may be greater than or equal to the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283. For example, in this embodiment, the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the second blue light emitting layer 283 may be interchanged with the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the blue doping material in the first blue light emitting layer 233, and the present disclosure is not limited to this.

[0113] In an exemplary embodiment, the material of the second green light-emitting layer 282 may include a green dopant material and one or two green main materials. The types of the green dopant material and the green main material may refer to the aforementioned description of the first green light-emitting layer 232, and the thickness of the second green light-emitting layer 282 may refer to the aforementioned description of the first green light-emitting layer 232, which will not be repeated here.

[0114] In an exemplary embodiment, the difference between the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light emitting layer 282 and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light emitting layer 232 may be greater than or equal to 1 nm and less than or equal to 10 nm. In this embodiment, by setting the green doping material in the second green light emitting layer 282 to be different from the green doping material in the first green light emitting layer 232, the difference between the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light emitting layer 282 and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light emitting layer 232 may be greater than or equal to 1 nm and less than or equal to 10 nm, which helps to reduce the brightness decay rate of green light with an increase in viewing angle, so that the brightness decay rates of red light, green light and blue light of the display substrate with an increase in viewing angle are close, and the color shift phenomenon of the display substrate is reduced. When the brightness decay rates of green light and blue light are close as the viewing angle increases, and the brightness decay rate of red light is slower than that of green light and blue light, the color deviation of the display substrate can be improved by adjusting the materials of the first green light-emitting layer 232, the second green light-emitting layer 282, the first blue light-emitting layer 233 and the second blue light-emitting layer 283. This method does not add new preparation steps, helps save costs, and is suitable for popularization and use.

[0115] In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light-emitting layer 282 may be greater than or equal to 530 nm and less than or equal to 540 nm. This embodiment is illustrated by taking the example that the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light-emitting layer 282 is greater than or equal to the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light-emitting layer 232. In other embodiments, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light-emitting layer 232 may be greater than or equal to the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light-emitting layer 282. For example, in this embodiment, the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the second green light-emitting layer 282 may be interchanged with the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the green doping material in the first green light-emitting layer 232, and the present disclosure is not limited thereto.

[0116] In an exemplary embodiment, the material and thickness of the second red light emitting layer 281 and the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the red doping material can refer to the above description of the first red light emitting layer 231 and are not repeated here.

[0117] In an exemplary embodiment, the material of the second electron transport layer 29 may be Figure 7The materials of the electron transport layer 14 are listed in the following, and the present disclosure does not limit them.

[0118] In example embodiments, the second electron transport layer 29 may have a thickness greater than or equal to 10 nm and less than or equal to 40 nm.

[0119] In an exemplary embodiment, the material and thickness of cathode 304 can be referred to as Figure 7 The description of the cathode 304, the material and thickness of the light extraction layer 305 can refer to Figure 7 The description of the middle cathode 304 is not repeated here.

[0120] Fig.12 The curve of the brightness of different colors of light on the display substrate attenuating with viewing angle can be referred to Fig.11 As shown, no further description is given here.

[0121] The embodiments of the present disclosure also provide a display device, including the display substrate described in any of the above embodiments. The display device can be: an OLED display, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, or any other product or component with a display function, and the embodiments of the present disclosure are not limited thereto.

[0122] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A display substrate, comprising: A substrate and a plurality of light-emitting devices disposed on the substrate, wherein the plurality of light-emitting devices include a red light-emitting device, a green light-emitting device and a blue light-emitting device, wherein the red light-emitting device includes a red light-emitting layer, the green light-emitting device includes a green light-emitting layer, and the blue light-emitting device includes a blue light-emitting layer; and a material of the red light-emitting layer includes a red doping material; The material of the green light-emitting layer includes one green doping material, and the material of the blue light-emitting layer includes two blue doping materials; or the material of the green light-emitting layer includes two green doping materials, and the material of the blue light-emitting layer includes two blue doping materials; The peak values ​​of the photoluminescence spectrum curves of the two green doping materials correspond to different wavelengths, and the peak values ​​of the photoluminescence spectrum curves of the two blue doping materials correspond to different wavelengths.

2. The display substrate according to claim 1, characterized in that: The difference between the wavelengths corresponding to the peaks of the photoluminescence spectrum curves of the two green doping materials is greater than or equal to 1 nm and less than or equal to 10 nm; The difference between the wavelengths corresponding to the peaks of the photoluminescence spectrum curves of the two blue doping materials is greater than or equal to 1 nm and less than or equal to 10 nm.

3. The display substrate according to claim 2, characterized in that: The two blue doping materials include a first blue doping material and a second blue doping material; wherein, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the first blue doping material is greater than or equal to 452nm and less than or equal to 458nm, and the wavelength corresponding to the peak of the photoluminescence spectrum curve of the second blue doping material is greater than or equal to 458nm and less than or equal to 464nm.

4. The display substrate according to claim 3, characterized in that: The material of the blue light-emitting layer includes two blue doping materials, including: the blue light-emitting device includes a blue light-emitting layer, and the first blue doping material and the second blue doping material are both doped in the blue light-emitting layer.

5. The display substrate according to claim 4, characterized in that: The thickness of the blue light emitting layer is greater than or equal to 20 nm and less than or equal to 30 nm.

6. The display substrate according to claim 3, characterized in that: The material of the blue light-emitting layer includes two blue doping materials, including: the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer arranged in sequence along a direction away from the substrate; one of the first blue doping material and the second blue doping material is doped in the first blue light-emitting layer, and the other is doped in the second blue light-emitting layer.

7. The display substrate according to claim 6, characterized in that: The thickness of the first blue light-emitting layer is greater than or equal to 15 nm and less than or equal to 25 nm, and the thickness of the second blue light-emitting layer is greater than or equal to 15 nm and less than or equal to 25 nm.

8. The display substrate according to claim 4 or 6, characterized in that: The two green doping materials include a first green doping material and a second green doping material; wherein the peak value of the photoluminescence spectrum curve of the first green doping material is greater than or equal to 520nm and less than or equal to 530nm, and the peak value of the photoluminescence spectrum curve of the second green doping material is greater than or equal to 530nm and less than or equal to 540nm.

9. The display substrate according to claim 8, characterized in that: In the case where the blue light-emitting device includes a blue light-emitting layer, the material of the green light-emitting layer includes two green doping materials, including: the green light-emitting device includes a green light-emitting layer, and the first green doping material and the second green doping material are both doped in the green light-emitting layer.

10. The display substrate according to claim 9, characterized in that: The thickness of the green light emitting layer is greater than or equal to 25 nm and less than or equal to 35 nm.

11. The display substrate according to claim 8, characterized in that: In the case where the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer, the material of the green light-emitting layer includes two green doping materials, including: the green light-emitting device includes a first green light-emitting layer and a second green light-emitting layer arranged in sequence along a direction away from the substrate; one of the first green doping material and the second green doping material is doped in the first green light-emitting layer, and the other is doped in the second green light-emitting layer.

12. The display substrate according to claim 11, characterized in that: The thickness of the first green light-emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm; the thickness of the second green light-emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm.

13. The display substrate according to claim 8, characterized in that: The wavelength corresponding to the peak value of the photoluminescence spectrum curve of the red doping material is greater than or equal to 622 nm and less than or equal to 632 nm.

14. The display substrate according to claim 13, characterized in that: In the case where the green light emitting device includes a green light emitting layer, and the blue light emitting device includes a blue light emitting layer, the red light emitting device includes a red light emitting layer; When the blue light-emitting device includes a first blue light-emitting layer and a second blue light-emitting layer, and the green light-emitting device includes a first green light-emitting layer and a second green light-emitting layer, the red light-emitting device includes a first red light-emitting layer and a second red light-emitting layer sequentially arranged in a direction away from the substrate.

15. A display device comprising the display substrate according to any one of claims 1 to 14.

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