Display substrate and display device

Abstract

A display substrate and a display device. The display substrate comprises a substrate and a plurality of light emitting devices disposed 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 peak values of the photoluminescence spectrum curves of the two green doping materials are different in wavelength, and the peak values of the photoluminescence spectrum curves of the two blue doping materials are different in wavelength.

Description

TECHNICAL FIELD

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

[0002] An organic light emitting diode (OLED) is an active light emitting display device, which has the advantages of self-emission, wide viewing angle, high contrast, low power consumption, and extremely high response speed. With the continuous development of display technology, a display device using an OLED as a light emitting element and controlled by a thin film transistor (TFT) has become a mainstream product in the current display field.

[0003] However, there is a color shift problem of display products at different viewing angles. SUMMARY

[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] In one aspect, the present disclosure provides a display substrate, comprising: a substrate and a plurality of light emitting devices disposed 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; a material of the red light emitting layer comprising a red dopant material; a material of the green light emitting layer comprising a green dopant material, and a material of the blue light emitting layer comprising two blue dopant materials; or, a material of the green light emitting layer comprising two green dopant materials, and a material of the blue light emitting layer comprising two blue dopant materials; wherein a peak value of a photoluminescence spectrum curve of the two green dopant materials corresponds to different wavelengths, and a peak value of a photoluminescence spectrum curve of the two blue dopant materials corresponds to different wavelengths.

[0007] In an example embodiment, a difference between the wavelengths corresponding to the peak values of the photoluminescence spectrum curves of the two green dopant materials is greater than or equal to 1 nm and less than or equal to 10 nm, and a difference between the wavelengths corresponding to the peak values of the photoluminescence spectrum curves of the two blue dopant materials is greater than or equal to 1 nm and less than or equal to 10 nm.

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

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

[0010] In an example 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 example embodiment, the material of the blue light emitting layer includes two blue dopant materials, including: the blue light emitting device includes a first blue light emitting layer and a second blue light emitting layer arranged in sequence away from the substrate; one of the first blue dopant material and the second blue dopant 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 example 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 example embodiment, the two green dopant materials include a first green dopant material and a second green dopant material; wherein a peak of a photoluminescence spectrum curve of the first green dopant material is greater than or equal to 520 nm and less than or equal to 530 nm, and a peak of a photoluminescence spectrum curve of the second green dopant material is greater than or equal to 530 nm and less than or equal to 540 nm.

[0014] In an example embodiment, 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 dopant materials, including: the green light emitting device includes a green light emitting layer, and the first green dopant material and the second green dopant material are both doped in the green light emitting layer.

[0015] In an example 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 one 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 disposed sequentially 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 one 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 one exemplary embodiment, the peak wavelength of the photoluminescence spectrum curve of the red doped material corresponds to a wavelength greater than or equal to 622 nm and less than or equal to 632 nm.

[0019] In one 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 sequentially disposed along a direction away from the substrate.

[0020] On the other hand, embodiments of this disclosure provide a display device including a display substrate as described above.

[0021] The display substrate provided in this disclosure addresses the issue where, with increasing viewing angle, the brightness decay rates of red and green light are relatively similar, and the decay rate of red and green light is slower than that of blue light. By incorporating two blue dopants into the blue emitting layer of the display substrate, the brightness decay rate of blue light with increasing viewing angle is slowed down. This results in the brightness decay rates of red, green, and blue light with increasing viewing angle being similar, significantly improving the color shift of the display substrate. Similarly, when the brightness decay rates of green and blue light are relatively similar with increasing viewing angle, while the brightness decay rate of red light is slower than that of green and blue light, the blue emitting layer and green emitting layer of the display substrate are also incorporating two blue dopants. This slows down the brightness decay rates of green and blue light with increasing viewing angle, resulting in the brightness decay rates of red, green, and blue light with increasing viewing angle being similar, significantly improving the color shift of the display substrate. This solves the problem of color shift in display products at different viewing angles.

[0022] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings.

[0023] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood. Attached Figure Description

[0024] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0025] Figure 1 This is a schematic diagram of the structure of a display device;

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

[0027] Figure 3 This is a schematic diagram of an equivalent circuit for a pixel driving circuit.

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

[0029] Figure 5 This is a graph showing the decrease in brightness of different colors of light as a function of viewing angle in a display substrate.

[0030] Figure 6 This is a graph showing the decrease in brightness of different colors of light as a function of viewing angle in another type of display substrate;

[0031] Figure 7 This is a schematic cross-sectional view of a display substrate in an exemplary embodiment.

[0032] Figure 8 Here are the photoluminescence spectra of two blue doped materials in an exemplary embodiment;

[0033] Figure 9 Here are the photoluminescence spectra of two green doped materials in an exemplary embodiment;

[0034] Figure 10 This is a photoluminescence spectrum of the red-doped material in an exemplary embodiment;

[0035] Figure 11 As an exemplary implementation Figure 7 The graph shown is a curve of the brightness of different colors of light on the display substrate decreasing with viewing angle.

[0036] Figure 12This is a cross-sectional view of the display substrate in yet another exemplary embodiment. Detailed Implementation

[0037] This disclosure describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0038] This disclosure includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this disclosure may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this disclosure may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0039] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that the method or process does not depend on the specific order of steps described herein. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims relating to the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments disclosed herein.

[0040] In the accompanying drawings, the size of one or more constituent elements, the thickness of layers, or areas are sometimes exaggerated for clarity. Therefore, this disclosure is not necessarily limited to these dimensions, and the shape and size of one or more parts in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate ideal examples, and this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0041] The ordinal numbers such as "first," "second," and "third" used in this specification are used to avoid confusion among the constituent elements, not to limit the quantity. The term "multiple" in this disclosure refers to two or more quantities.

[0042] In this specification, for convenience, terms such as "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships in conjunction with the accompanying drawings. This is solely for the purpose of facilitating the description and simplification, and does not imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this disclosure. The positional relationships of the constituent elements may be appropriately varied depending on the orientation of the constituent elements being described. Therefore, the use of terms not limited to those described in the specification may be appropriately replaced as needed.

[0043] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art will understand the meaning of these terms in this disclosure as appropriate.

[0044] In this specification, "electrical connection" includes the situation where components are connected together by elements that have a certain electrical function. There are no particular limitations on what constitutes an "electrical function," as long as it allows for the transmission of electrical signals between the connected components. Examples of "electrical functions" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0045] In this specification, "parallel" refers to the state where the angle formed by two straight lines is greater than or equal to -10° and less than 10°, and therefore also includes the state where the angle is greater than or equal to -5° and less than 5°. Similarly, "perpendicular" refers to the state where the angle formed by two straight lines is greater than or equal to 80° and less than 100°, and therefore also includes the state where the angle is greater than or equal to 85° and less than 95°.

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

[0047] Figure 1 This 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 emission 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 emission 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 emission signal driver is configured to sequentially provide light emission control signals to the plurality of light emission signal lines (EM(1) to EM(N)). In some exemplary embodiments, the plurality of scan signal lines and the plurality of light emission 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 each sub-pixel includes a pixel driving circuit and a light emission device. The pixel driving circuit is connected to the scan signal line, the light emission control line, and the data signal line. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line and output a corresponding current to the light-emitting device under the control of the scan signal line and the light emission signal line. The light-emitting device is connected to the pixel driving circuit and is configured to emit light of a 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 a first power supply voltage, a second power supply voltage, and an 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 This is a schematic diagram of a planar structure of a display substrate. Figure 2 As shown, the display area may include multiple pixel units P arranged in a matrix. At least one of the multiple 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, second sub-pixel P2, and 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 red (R) sub-pixels, green (G) sub-pixels, and blue (B) sub-pixels, or it may include red sub-pixels, green sub-pixels, blue sub-pixels, and white (W) sub-pixels; this disclosure does not limit the scope of the invention. In some exemplary embodiments, the shape of the sub-pixels in the pixel unit may be rectangular, rhomboid, pentagonal, or hexagonal. When the pixel unit includes three sub-pixels, the three sub-pixels may be arranged horizontally side-by-side, vertically side-by-side, or in a triangular arrangement; when the pixel unit includes four sub-pixels, the four sub-pixels may be arranged horizontally side-by-side, vertically side-by-side, or in a square arrangement. However, this disclosure does not limit the scope of the invention.

[0049] In some exemplary embodiments, the pixel driving circuit may be a 3T1C, 4T1C, 5T1C, 5T2C, 6T1C or 7T1C structure. Figure 3 This is an equivalent circuit diagram of a pixel driving circuit. (Example) Figure 3 As shown, the pixel driving circuit may include seven switching transistors (first transistor T1 to seventh transistor T7), one storage capacitor C, and eight 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 supply line VSS, second power supply line VDD, and light emission signal line EM). 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 emission 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 scan 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 terminal of the storage capacitor C is connected to the second power supply line VDD, and the second terminal 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 can be P-type transistors or N-type transistors. Using the same type of transistor in the pixel driving circuit can simplify the process flow, reduce the manufacturing difficulty of the display panel, and improve the product yield. In some possible implementations, the first transistor T1 to the seventh transistor T7 may include both P-type and N-type transistors.

[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 high-level signal. The first scan signal line S1 is the scan signal line in the pixel driving circuit of this display row, and the second scan signal line S2 is the scan signal line in the pixel driving 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 this display row is the same signal line as the first scan signal line S1 in the pixel driving circuit of the previous display row, which can reduce the signal lines of the display panel and realize a narrow bezel of the display panel.

[0053] Figure 4 This is a cross-sectional structural diagram of a display substrate, illustrating the structure of three sub-pixels. For example... Figure 4 As shown, on a plane perpendicular to the display substrate, the display substrate may include a driving circuit layer 102 disposed on the substrate 101, a light-emitting device 103 disposed on the side of the driving circuit layer 102 away from the substrate 101, and an encapsulation layer 104 disposed on the 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 herein.

[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 and second flexible material layers may be polyimide (PI), polyethylene terephthalate (PET), or surface-treated polymer films, etc. The materials of the first and second inorganic material layers may be silicon nitride (SiNx) or silicon oxide (SiOx), etc., to improve the substrate's resistance to water and oxygen. 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 4The illustration uses an example where 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, with vias formed in the second insulating layer 202, the third insulating layer 203, and the fourth insulating layer 204, exposing the active layer; a source electrode and a drain electrode disposed on the fourth insulating layer 204, the source electrode and the drain electrode being connected to the active layer through vias; and a planarization layer 205 covering the aforementioned structure, with vias formed in the planarization layer 205, exposing 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 planarization layer 205 and connected to the drain electrode of the driving transistor 210 through a via formed in the planarization layer 205; the pixel definition layer 302 is disposed on the anode 301 and the planarization layer 205, and the pixel definition layer 302 is provided with a pixel opening that exposes the anode 301; the organic light-emitting layer 303 is at least partially disposed within the pixel opening and is connected to the anode 301; the cathode 304 is disposed on the organic light-emitting layer 303 and is connected to the organic light-emitting layer 303; the organic light-emitting layer 303 emits light of a corresponding color under the drive of the anode 301 and the cathode 304.

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

[0058] In some exemplary embodiments, the organic light-emitting layer of the light-emitting device may include an emitting layer (EML) and one or more films selected from the following: a hole injection layer (HIL), a hole transport layer (HTL), a hole block layer (HBL), an electron block layer (EBL), an electron injection layer (EIL), and an electron transport layer (ETL). Driven by the voltages of the anode and cathode, the light-emitting properties of the organic material are utilized to emit light at the required grayscale.

[0059] In some exemplary embodiments, the emitting layers of OLED light-emitting devices of different colors are different. For example, a red light-emitting device includes a red emitting layer, a green light-emitting device includes a green emitting layer, and a blue light-emitting device includes a blue emitting layer. To reduce process complexity and improve yield, the hole injection layer and hole transport layer on one side of the emitting layer can be common layers, and the electron injection layer and electron transport layer on the other side of the emitting layer can also be common layers. In some exemplary embodiments, any one or more of the hole injection layer, hole transport layer, electron injection layer, and electron transport layer can be fabricated in a single process (single vapor deposition process or single inkjet printing process), but isolation is achieved through surface steps of the formed film layers or through surface treatment. For example, any one or more of the hole injection layer, hole transport layer, electron injection layer, and electron transport layer corresponding to adjacent sub-pixels can be isolated. In some exemplary embodiments, the organic light-emitting layer can be formed by vapor deposition using a fine metal mask (FMM) or an open mask, or by inkjet printing.

[0060] In a display substrate, light-emitting devices of different colors have the same film structure. Because the full width at half maximum (FWHM) of different colors of light are different, the brightness of different colors of light decreases at different rates with viewing angle, and users will feel obvious color shift when viewing the display.

[0061] Figure 5 This is a graph illustrating the attenuation of brightness of different colors of light with viewing angle in a display substrate, using an example of a display substrate containing red, green, and blue light-emitting devices. Figure 5As shown, the horizontal axis represents the viewing angle in degrees, and the vertical axis represents the percentage of brightness. The screen brightness is set to 100% when viewing the screen from the front (i.e., the viewing angle between the user and the display substrate is 0 degrees). As the viewing angle increases, the brightness of different colors of light gradually decreases. Figure 5 In the diagram, L1 represents red light, L2 represents green light, and L3 represents blue light. Figure 5 It can be observed that as the viewing angle increases, the brightness decay rates of green and blue light are relatively similar, while the brightness decay rate of red light is slower than that of green and blue light. This asynchronous brightness decay leads to color shift in the display substrate.

[0062] Figure 6 This is a graph showing the decrease in brightness of different colors of light as a function of viewing angle in another type of display substrate. Figure 6 and Figure 5 The only difference lies in how the brightness of different colors of light changes with increasing viewing angle. For example... Figure 6 As shown, in some implementations, the brightness decay rates of red and green light may be similar as the viewing angle increases, and the brightness decay rates of red and green light are slower than those of blue light. This situation can also lead to color shift in the display substrate.

[0063] This disclosure provides a display substrate, including: a substrate and a plurality of light-emitting devices disposed on the substrate. The plurality of light-emitting devices include a red light-emitting device, a green light-emitting device, and a blue light-emitting device. 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. The material of the red light-emitting layer includes a red dopant material; the material of the green light-emitting layer includes a green dopant material, and the material of the blue light-emitting layer includes two blue dopant materials; or, the material of the green light-emitting layer includes two green dopant materials, and the material of the blue light-emitting layer includes two blue dopant materials; wherein the peak values ​​of the photoluminescence spectral curves of the two green dopant materials correspond to different wavelengths, and the peak values ​​of the photoluminescence spectral curves of the two blue dopant materials correspond to different wavelengths.

[0064] The display substrate provided in this disclosure, when the brightness decay rates of red and green light are relatively similar with increasing viewing angle, and the brightness decay rates of red and green light are slower than those of blue light, improves the color shift of the display substrate by including two blue dopants in the material of the blue emitting layer. This slows down the brightness decay rate of blue light with increasing viewing angle, thereby making the brightness decay rates of red, green, and blue light with increasing viewing angle similar, significantly improving the color shift of the display substrate. Similarly, when the brightness decay rates of green and blue light are relatively similar with increasing viewing angle, while the brightness decay rate of red light is slower than that of green and blue light, the display substrate's blue emitting layer and green emitting layer, both comprised of two blue dopants, slows down the brightness decay rates of green and blue light with increasing viewing angle, thus making the brightness decay rates of red, green, and blue light with increasing viewing angle similar, significantly improving the color shift of the display substrate.

[0065] Figure 7 This is a schematic cross-sectional view of a display substrate in an exemplary embodiment. Figure 4 compared to, Figure 7 The diagram illustrates in detail the structure of the light-emitting device 103, including the structure of the driving circuit layer 102 and the encapsulation layer 104, as well as other film layers. This can be referred to in the diagram. Figure 4 The description will not be repeated here.

[0066] like Figure 7 As shown, along 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 disposed sequentially. The light-emitting device 103 may also include a light extraction layer 305 disposed on the side of the cathode 304 away from the substrate 101.

[0067] In an exemplary embodiment, the hole injection layer can be a common layer, the hole transport layer can be a common layer, and the hole injection layer and the hole transport layer sequentially cover the side of the anode 301 and the pixel definition layer 302 away from the substrate 101. Figure 7 Reference numeral 11 denotes the hole injection layer and the hole transport layer. 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, and 1,3,5-tris(N-3-methylphenyl-N-phenylamino)benzene (TDAB). Other types of hole transport materials may be selected as needed, and this disclosure does not limit this selection.

[0068] In an exemplary embodiment, the material of the hole injection layer can be obtained by doping the material of the hole transport layer with a hole injection material, thereby achieving a good transition between the hole injection layer and the hole transport layer. 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 can include any one or more of the following: NDP series p-type doped materials (including NDP-2, NDP-9, etc.), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-phenyl (F4-TCNQ), and tris(4-bromophenyl)hexachloroantimonylate (TBAHA). Other types of hole injection materials and hole transport materials can be selected as needed, and this disclosure does not limit this selection.

[0069] In an exemplary embodiment, the thickness of the hole injection layer can be greater than or equal to 1 nm and less than or equal to 10 nm. In this embodiment of the disclosure, the thickness of "film layer A" is the distance between the surface of "film layer A" on the side close to the substrate 101 and the surface on the side 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) level of the electron blocking layer... EBL HOMO level below hole transport layer HTL For example, HOMO EBL and HOMO HTL The difference between them can be approximately 0.2 eV. The lowest unoccupied molecular orbital (LUMO) level of the electron blocking layer... EBL LUMO energy level above the luminescent layer EML For example, LUMO EBL and LUMO EML The difference between them can be approximately 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, green electron blocking layer 122, and blue electron blocking layer 123 can be fabricated using vacuum evaporation processes, respectively, using high-precision red, green, and blue metal masks. This disclosure does not limit the scope of the invention.

[0072] In an exemplary embodiment, the material of the electron blocking layer may include any one or more of the following: 2-(4-tert-butylphenyl)-5-(4-biphenyl)1,3,4-diazole, 3(biphenyl)-4-benzene-5–(4-tert-butylphenyl)-4H-1,2,4-triazole, which are not limited herein.

[0073] In an exemplary embodiment, the thickness of the electron blocking layer can be greater than or equal to 5 nm and less than or equal to 100 nm. The thicknesses of the red electron blocking layer 121, the green electron blocking layer 122, and the blue electron blocking layer 123 can be set as needed, and this disclosure does not limit this.

[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 using a vacuum evaporation process, respectively using red, green, and blue high-precision metal masks. This disclosure does not limit this.

[0075] In an exemplary embodiment, the material of the blue emitting layer 133 may include two blue dopants and one or two blue host materials, wherein the peak values ​​of the photoluminescence spectral curves of the two blue dopants correspond to different wavelengths. The hole mobility of the blue host material is higher than that of the electron mobility. The blue host material may include any one or more of the following: 3-tert-butyl-9,10-bis(2-naphthyl)anthracene, 2-methyl-9,10-bis(naphthyl-2-yl)anthracene, (2,2-stilbene)-1,1c biphenyl, and this disclosure is not limited thereto. By setting the material of the blue emitting layer 133 to include two blue dopants, and the peak values ​​of the photoluminescence spectral curves of the two blue dopants correspond to different wavelengths, it helps to reduce the brightness decay rate of blue light with increasing viewing angle, thereby making the brightness decay rates of red, green, and blue light of the display substrate similar with increasing viewing angle, and reducing the color shift phenomenon of the display substrate. When the brightness decay rates of red and green light are similar as the viewing angle increases, and the brightness decay rates of red and green light are slower than those of blue light, the color shift of the display substrate can be improved simply by adjusting the material of the blue light-emitting layer 133. This method does not add any new preparation steps, helps to save costs, and is suitable for widespread use.

[0076] In exemplary embodiments, the blue doping material may include any one or more of the following: 4,4'-bis(9-ethyl-3-carbazolevinyl)-1,1'-biphenyl, 1,1,4,4-tetraphenylbutadiene, 4'-(4-(diphenylamino)phenyl)-5'-phenyl-[1,1':2',1”-triphenyl]-4-nitrile, 1,4-di-[4-(N,N-diphenyl)amino]styrylbenzene, etc. Other suitable blue doping materials may be selected as needed, and this disclosure does not limit them.

[0077] Figure 8 This is a photoluminescence spectrum of two blue doped 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 peak wavelength of the photoluminescence spectrum of the first blue doped material B1 and the peak wavelength of the photoluminescence spectrum of the second blue doped material B2 can be greater than or equal to 1 nm and less than or equal to 10 nm. For example, the peak wavelength of the photoluminescence spectrum of the first blue doped material B1 can be greater than or equal to 452 nm and less than or equal to 458 nm, and the peak wavelength of the photoluminescence spectrum of the second blue doped material B2 can be greater than or equal to 458 nm and less than or equal to 464 nm.

[0078] In an exemplary embodiment, the thickness of the blue emitting layer 133 can 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 emitting layer 132 may include two green dopants and one or two green host materials, wherein the peak ranges of the photoluminescence spectral curves of the two green dopants are different. A suitable green host material can be selected as needed; the green dopants may include iridium-based or platinum-based compounds, and this disclosure is not limited thereto. By setting the material of the green emitting layer 132 to include two green dopants, and the peak values ​​of the photoluminescence spectral curves of the two green dopants being different, it helps to reduce the brightness decay rate of green light as the viewing angle increases, thereby making the brightness decay rates of red, green, and blue light on the display substrate similar as the viewing angle increases, reducing the color shift phenomenon of the display substrate. When the brightness decay rates of green and blue light are relatively similar as the viewing angle increases, while the brightness decay rate of red light is slower than that of green and blue light, the color shift of the display substrate can be improved by adjusting the materials of the green emitting layer 132 and the blue emitting layer 133. This method does not add new preparation steps, helps to save costs, and is suitable for widespread use.

[0080] Figure 9 The image shows the photoluminescence spectra of two green doped materials in one exemplary embodiment. Figure 9The horizontal axis represents wavelength in nm, and the vertical axis represents intensity. The difference D2 between the peak wavelength of the photoluminescence spectrum of the first green doped material G1 and the peak wavelength of the photoluminescence spectrum of the second green doped material G2 can be greater than or equal to 1 nm and less than or equal to 10 nm. For example, the peak wavelength of the photoluminescence spectrum of the first green doped material G1 can be greater than or equal to 520 nm and less than or equal to 530 nm, and the peak wavelength of the photoluminescence spectrum of the second green doped material G2 can be greater than or equal to 530 nm and less than or equal to 540 nm.

[0081] In an exemplary embodiment, the thickness of the green light-emitting layer 132 can 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 emitting layer 131 may include a red dopant material and one or two red host materials. The red host material may be, for example, 4,4′4″-tris(N-carbazole)triphenylamine, and the red dopant material may include iridium compounds or platinum compounds. For example, the red dopant material may include one or more of the following materials: bis[2-(2′-benzo-4,5-α-thiophene)pyridine]acetylacetone iridium, tris(1-phenyl-isoquinoline)iridium(III); tris[1-phenylisoquinoline-C2,N]iridium, which are not limited in this disclosure.

[0083] Figure 10 The photoluminescence spectrum of the red-doped material is shown in an exemplary embodiment. Figure 10 The horizontal axis represents wavelength in nm, and the vertical axis represents intensity. The peak value of the photoluminescence spectrum of the red-doped material R1 can be greater than or equal to 622 nm and less than or equal to 632 nm.

[0084] In an exemplary embodiment, the thickness of the red emitting layer 131 can 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-bis(1-naphthyl)-1,3,5-oxadiazole (BND), 2,4,6-triphenoxy-1,3,5-triazine (TRZ), which are not limited herein.

[0086] In an exemplary embodiment, 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 metallic materials: Mg, Ag, Al, Li, K, Ca, or may include an alloy of the above metallic materials, such as Mg. x Ag (1-x) Li x Al (1-x) Li x Ca (1-x) Li x Ag (1-x) This disclosure does not impose any restrictions on this matter.

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

[0089] In an exemplary embodiment, the light extraction layer 305 can be made of a high refractive index material. For example, under light with a wavelength range from 450 nm to 780 nm, the refractive index of the light extraction layer 305 can be greater than 2.0, i.e., n > 2.0 @ 450 ~ 780 nm. The light extraction layer 305 can also be made of a high transmittance material. For example, under light with a wavelength range from 450 nm to 780 nm, the light absorption coefficient k of the light extraction layer 305 can be less than or equal to 0.01, i.e., k ≤ 0.01 @ 450 ~ 780 nm.

[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), triphenyldiamine derivative (TPD), N,N'-diphenyl-N,N'-di(4'-(N,N-di(1-naphthyl)-amino)-4-biphenyl)-benzidine (TPTE), 1,3,5-tris(N-3-methylphenyl-N-phenylamino)benzene (TDAB), copper phthalocyanine (CuPc), etc.

[0091] In an exemplary embodiment, 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] Figure 11 As an exemplary implementation Figure 7 The graph shown illustrates the decrease in brightness of different colors of light on the display substrate as a function of viewing angle. Figure 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. From Figure 11 It can be seen from this that, with Figure 5 or Figure 6 compared to, Figure 11The brightness of different colors of light decreases at roughly the same rate with increasing viewing angle, indicating that the use of... Figure 7 The proposed solution can effectively address the color shift problem of display substrates.

[0093] Figure 12 This is a cross-sectional view of the display substrate in yet another exemplary embodiment. Figure 12 and Figure 7 The difference lies in the structure of the organic light-emitting layer 303; the remaining structures can be referred to the aforementioned description. Figure 7 The description will not be repeated here.

[0094] like Figure 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 sequentially disposed.

[0095] In an exemplary embodiment, the hole injection layer can be a common layer, the first hole transport layer can be a common layer, and the hole injection layer and the first hole transport layer sequentially cover the side of the anode 301 and the pixel definition layer 302 away from the substrate 101. Figure 12 In this embodiment, the hole injection layer and the first hole transport layer are designated by reference numeral 21. The materials and thicknesses of the hole injection layer and the first hole transport layer in this embodiment can be referenced from [reference needed]. Figure 7 The descriptions of the hole injection layer and 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 221 may be greater than the thickness of the first green electron blocking layer 222, and the thickness of the first green electron blocking layer 222 may be greater than the thickness of the first blue electron blocking layer 223. 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 can be referred to [reference needed]. Figure 7 The relevant description of the electron blocking layer will not be repeated here.

[0097] In an exemplary embodiment, 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 emitting layer 233 may include a blue dopant material and one or two blue host materials. The types of blue dopant material and blue host material can be referenced to... Figure 7The description of the blue emitting layer 133 will not be repeated here. In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the blue doped material in the first blue emitting layer 233 can be greater than or equal to 452 nm and less than or equal to 458 nm.

[0099] In an exemplary embodiment, the thickness of the first blue emitting layer 233 can 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 dopant material and one or two green host materials. The types of green dopant material and green host material can be referenced to... Figure 7 The description of the green light-emitting layer 132 will not be repeated here. In an exemplary embodiment, the wavelength corresponding to the peak of the photoluminescence spectrum curve of the green doped material in the first green light-emitting layer 232 can be greater than or equal to 520 nm and less than or equal to 530 nm.

[0101] In an exemplary embodiment, 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 emitting layer 231, as well as the wavelength range corresponding to the peak value of the photoluminescence spectrum curve of the red doped material, can be referenced to... Figure 7 The description of the red luminescent layer 131 will not be repeated here.

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

[0104] In an exemplary embodiment, 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 can be referred to the foregoing description of the material of the first hole injection layer, and 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. The electron transport layer material can be selected as needed. The doped metal material may include Li, Yb, etc., and may be doped with one or more metal materials, or may be an alloy of multiple metal materials. This disclosure does not limit this.

[0106] In an exemplary embodiment, the thickness of the second charge generation layer can be greater than or equal to 5 nm and less than or equal to 10 nm. The thickness of the charge generation layer 25 can be set as needed, and this disclosure does not limit it.

[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. The thicknesses of the second hole transport layer 26 and the first hole transport layer can be set as needed, and this disclosure does not impose any limitations on this. The material of the second hole transport layer 26 can refer to the foregoing description of the first hole transport layer, for example, it can be 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 can be referred to the foregoing description of the first electron blocking layer, and will not be repeated here.

[0109] In an exemplary embodiment, 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 host materials. The types of blue dopant material and blue host material can be referred to the foregoing description of the first blue light-emitting layer 233. The thickness of the second blue light-emitting layer 283 can be referred to the foregoing description of the first blue light-emitting layer 233, and will not be repeated here.

[0111] In an exemplary embodiment, the difference between the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue dopant material in the second blue emitting layer 283 and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue dopant material in the first blue emitting layer 233 can be greater than or equal to 1 nm and less than or equal to 10 nm. In this embodiment, by setting the blue dopant material in the second blue emitting layer 283 to be different from the blue dopant material in the first blue emitting layer 233, the difference between the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue dopant material in the second blue emitting layer 283 and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue dopant material in the first blue emitting layer 233 can be greater than or equal to 1 nm and less than or equal to 10 nm. This helps to reduce the brightness decay rate of blue light as the viewing angle increases, thereby making the brightness decay rates of red, green, and blue light on the display substrate similar as the viewing angle increases, and reducing the color shift phenomenon of the display substrate. When the brightness decay rates of red and green light are similar as the viewing angle increases, and the brightness decay rates of red and green light are slower than those of blue light, the color shift of the display substrate can be improved simply 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 to save costs, and is suitable for widespread use.

[0112] In an exemplary embodiment, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the second blue emitting layer 283 can be greater than or equal to 458 nm and less than or equal to 464 nm. This embodiment illustrates this by taking as an example that the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the second blue emitting layer 283 is greater than or equal to the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the first blue emitting layer 233. In other embodiments, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the first blue emitting layer 233 can be greater than or equal to the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the second blue emitting layer 283. For example, in this embodiment, the wavelength range corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the second blue emitting layer 283 can be interchanged with the wavelength range corresponding to the peak value of the photoluminescence spectrum curve of the blue doped material in the first blue emitting layer 233. This disclosure does not impose any limitations on 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 host materials. The types of green dopant material and green host material can be referred to the foregoing description of the first green light-emitting layer 232, and the thickness of the second green light-emitting layer 282 can be referred to the foregoing description of the first green light-emitting layer 232, and will not be repeated here.

[0114] In an exemplary embodiment, the difference between the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green dopant material in the second green emitting layer 282 and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green dopant material in the first green emitting layer 232 can be greater than or equal to 1 nm and less than or equal to 10 nm. In this embodiment, by setting the green dopant material in the second green emitting layer 282 to be different from the green dopant material in the first green emitting layer 232, the difference between the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green dopant material in the second green emitting layer 282 and the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green dopant material in the first green emitting layer 232 can be greater than or equal to 1 nm and less than or equal to 10 nm. This helps to reduce the brightness decay rate of green light as the viewing angle increases, thereby making the brightness decay rates of red, green, and blue light of the display substrate similar as the viewing angle increases, and reducing the color shift phenomenon of the display substrate. When the brightness decay rate of green and blue light is similar as the viewing angle increases, while the brightness decay rate of red light is slower than that of green 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 to save costs, and is suitable for widespread use.

[0115] In an exemplary embodiment, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the second green emitting layer 282 can be greater than or equal to 530 nm and less than or equal to 540 nm. This embodiment illustrates this by taking as an example that the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the second green emitting layer 282 is greater than or equal to the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the first green emitting layer 232. In other embodiments, the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the first green emitting layer 232 can be greater than or equal to the wavelength corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the second green emitting layer 282. For example, in this embodiment, the wavelength range corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the second green emitting layer 282 can be interchanged with the wavelength range corresponding to the peak value of the photoluminescence spectrum curve of the green doped material in the first green emitting layer 232. This disclosure does not impose any limitations on this.

[0116] In an exemplary embodiment, the material and thickness of the second red emitting layer 281, as well as the wavelength range corresponding to the peak of the photoluminescence spectrum curve of the red doped material, can be referred to the aforementioned description of the first red emitting layer 231, and will not be 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 listed herein are not limited thereto.

[0118] In an exemplary embodiment, the thickness of the second electron transport layer 29 may be 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 the cathode 304 can be referenced to... Figure 7 The description of the cathode 304, and the material and thickness of the light extraction layer 305 can be found in the description of the cathode 304. Figure 7 The description of the intermediate cathode 304 will not be repeated here.

[0120] Figure 12 The curves showing the decrease in brightness of different colors of light on the display substrate as a function of viewing angle can be referenced. Figure 11 As shown, it will not be elaborated further here.

[0121] This disclosure also provides a display device, including the display substrate described in any of the above embodiments. The display device can be any product or component with display function, such as an OLED display, mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator, and this disclosure is not limited thereto.

[0122] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to 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, the plurality of light-emitting devices including a red light-emitting device, a green light-emitting device and a blue light-emitting device, the red light-emitting device including a red light-emitting layer, the green light-emitting device including a green light-emitting layer, the blue light-emitting device including a blue light-emitting layer; the material of the red light-emitting layer includes a red doped material; The green light-emitting layer is made of two green doped materials, and the blue light-emitting layer is made of two blue doped materials; The peak values ​​of the photoluminescence spectral curves of the two green doped materials correspond to different wavelengths, and the peak values ​​of the photoluminescence spectral curves of the two blue doped materials correspond to different wavelengths. The difference between the wavelengths corresponding to the peak values ​​of the photoluminescence spectral curves of the two green doped 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 peak values ​​of the photoluminescence spectral curves of the two blue doped materials is greater than or equal to 1 nm and less than or equal to 10 nm.

2. The display substrate according to claim 1, characterized in that, The two blue doped materials include a first blue doped material and a second blue doped material; wherein, the peak wavelength of the photoluminescence spectrum curve of the first blue doped material is greater than or equal to 452 nm and less than or equal to 458 nm, and the peak wavelength of the photoluminescence spectrum curve of the second blue doped material is greater than or equal to 458 nm and less than or equal to 464 nm.

3. The display substrate according to claim 2, characterized in that, The material of the blue light-emitting layer includes two blue doping materials, namely: the blue light-emitting device includes a blue light-emitting layer, wherein the first blue doping material and the second blue doping material are both doped in the blue light-emitting layer.

4. The display substrate according to claim 3, characterized in that, The thickness of the blue emitting layer is greater than or equal to 20 nm and less than or equal to 30 nm.

5. The display substrate according to claim 2, 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 disposed sequentially along the 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.

6. The display substrate according to claim 5, characterized in that, The thickness of the first blue 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 emitting layer is greater than or equal to 15 nm and less than or equal to 25 nm.

7. The display substrate according to claim 3 or 5, characterized in that, The two green doped materials include a first green doped material and a second green doped material; wherein, the peak value of the photoluminescence spectrum curve of the first green doped material is 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 doped material is greater than or equal to 530 nm and less than or equal to 540 nm.

8. The display substrate according to claim 7, 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, namely: the green light-emitting device includes a green light-emitting layer, and both the first green doping material and the second green doping material are doped in the green light-emitting layer.

9. The display substrate according to claim 8, 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.

10. The display substrate according to claim 7, 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, namely: the green light-emitting device includes a first green light-emitting layer and a second green light-emitting layer disposed sequentially 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.

11. The display substrate according to claim 10, characterized in that, The thickness of the first green emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm; the thickness of the second green emitting layer is greater than or equal to 20 nm and less than or equal to 35 nm.

12. The display substrate according to claim 7, characterized in that, The peak wavelength of the photoluminescence spectrum curve of the red doped material is greater than or equal to 622 nm and less than or equal to 632 nm.

13. The display substrate according to claim 12, 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; In the case where 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 along a direction away from the substrate.

14. A display device comprising a display substrate as claimed in any one of claims 1-13.

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