Display substrates and their fabrication methods, display panels, and display devices.

Abstract

This disclosure provides a display substrate, comprising: a plurality of repeating units; each repeating unit includes a first light-emitting element, a second light-emitting element, a third light-emitting element, and a photoelectric conversion element; the number of the first light-emitting elements and the third light-emitting elements is the same; the number of the second light-emitting elements and the photoelectric conversion element is the same; the number of the second light-emitting elements is twice the number of the first light-emitting elements; the first light-emitting elements, the second light-emitting elements, and the third light-emitting elements are arranged sequentially along a first direction; the second light-emitting elements and the photoelectric conversion elements are arranged sequentially along a second direction; the first direction and the second direction form an angle greater than 0° and less than or equal to 90°; the photoelectric conversion elements and the second light-emitting elements are adjacent and distributed in a one-to-one correspondence; any corresponding group of second light-emitting elements and photoelectric conversion elements are arranged along the first direction; the first light-emitting element or the third light-emitting element is located between two adjacent photoelectric conversion elements.

Description

Technical Field

[0001] This disclosure pertains to the field of display technology, specifically relating to a display substrate and its preparation method, a display panel, and a display device. Background Technology

[0002] In the disclosed technology, a color filter layer (including color resist and black matrix) is set on the light-emitting side of the OLED (Organic Light-Emitting Diode) display substrate, which can improve the color gamut and color purity of the OLED display substrate, thereby improving the display effect of the OLED display substrate. Summary of the Invention

[0003] This disclosure provides a display substrate and its preparation method, a display panel, and a display device.

[0004] In a first aspect, embodiments of the present disclosure provide a display substrate, comprising: a plurality of repeating units;

[0005] The repeating unit includes a first light-emitting element, a second light-emitting element, a third light-emitting element, and a photoelectric conversion element;

[0006] The number of the first light-emitting element and the third light-emitting element is the same; the number of the second light-emitting element and the photoelectric conversion element is the same; the number of the second light-emitting element is twice the number of the first light-emitting element.

[0007] The first light-emitting element, the second light-emitting element, and the third light-emitting element are arranged sequentially along a first direction; the second light-emitting element is arranged sequentially along a second direction; the photoelectric conversion element is arranged sequentially along the second direction.

[0008] The first direction and the second direction form an angle greater than 0° and less than or equal to 90°;

[0009] The photoelectric conversion element is adjacent to and corresponds one-to-one with the second light-emitting element; any corresponding group of the second light-emitting element and the photoelectric conversion element are arranged along the first direction; the first light-emitting element or the third light-emitting element is located between two adjacent photoelectric conversion elements.

[0010] In some embodiments, in the repeating unit, there is one first light-emitting element and two second light-emitting elements;

[0011] The two second light-emitting elements are respectively disposed on the upper and lower sides of the line connecting the center of the light-emitting area of ​​the first light-emitting element and the center of the light-emitting area of ​​the third light-emitting element;

[0012] The two photoelectric conversion elements are respectively located on the upper and lower sides of the line connecting the center of the light-emitting area of ​​the first light-emitting element and the center of the light-emitting area of ​​the third light-emitting element.

[0013] In some embodiments, in the repeating unit, the distance between the center of the light-emitting region of the two second light-emitting elements and the line connecting the center of the light-emitting region of the first light-emitting element and the center of the light-emitting region of the third light-emitting element is equal;

[0014] The distance between the center of the light-receiving region of the two photoelectric conversion elements and the line connecting the center of the light-emitting region of the first light-emitting element and the center of the light-emitting region of the third light-emitting element is equal.

[0015] In some embodiments, the first direction is perpendicular to the second direction;

[0016] In the repeating unit, the distance between the center of the emitting region of a corresponding set of second emitting elements and the center of the light-receiving region of the photoelectric conversion element is equal to the distance between the center of the emitting region of another corresponding set of second emitting elements and the center of the light-receiving region of the photoelectric conversion element.

[0017] In some embodiments, in the repeating unit, the center of the light-emitting region of the first light-emitting element and the center of the light-emitting region of the third light-emitting element are located on the same straight line along the first direction.

[0018] In some embodiments, the light-emitting region of the first light-emitting element has a first maximum width along the first direction and a second maximum width along the second direction;

[0019] 0.67 ≤ First maximum width / Second maximum width ≤ 1.5;

[0020] The first maximum width is ≥20μm; the second maximum width is ≥20μm.

[0021] In some embodiments, the light-emitting region of the third light-emitting element has a third maximum width along the first direction and a fourth maximum width along the second direction;

[0022] 0.67 ≤ the third maximum width / the fourth maximum width ≤ 1.5;

[0023] The third maximum width is ≥20μm; the fourth maximum width is ≥20μm.

[0024] In some embodiments, in the repeating unit, the minimum distance between the light-emitting regions of the two second light-emitting elements is ≥20μm.

[0025] In some embodiments, the light-receiving region area of ​​the photoelectric conversion element is greater than 100 μm.2 .

[0026] In some embodiments, the plurality of repeating units are arranged in an array, the row direction of the array is along the first direction, and the column direction of the array is along the second direction;

[0027] Each of the repeating units in any two adjacent rows is located in a different column;

[0028] In any two adjacent rows of repeating units, the photoelectric conversion elements that are close to each other along the second direction are located on the same straight line along the first direction.

[0029] The m-th repeating unit in the nth row and the (n+2th)-th repeating unit is located on the same straight line along the second direction; where n = 1, 2, 3, ..., and n is an integer; m = 1, 2, 3, ..., and m is an integer;

[0030] In the array, the spacing between any two adjacent photoelectric conversion elements located on the same straight line along the second direction is equal to the spacing between any two adjacent photoelectric conversion elements located on the same straight line along the first direction.

[0031] In some embodiments, in two adjacent rows of repeating units, and in two adjacent repeating units located in different rows, the distance between the light-receiving region center of the photoelectric conversion element located between two adjacent second light-emitting elements along the first direction and the light-emitting region center of the two second light-emitting elements is equal.

[0032] In some embodiments, the photoelectric conversion element includes a functional layer;

[0033] The first light-emitting element and the third light-emitting element each include a light-emitting layer;

[0034] At least one edge of the functional layer is parallel to at least one edge of the light-emitting layer of the adjacent first light-emitting element or the third light-emitting element.

[0035] In some embodiments, the shape of the light-emitting area of ​​the first light-emitting element is any one of a circle, an ellipse, a triangle, a rhombus, a rectangle, or a regular polygon;

[0036] The shape of the light-emitting area of ​​the third light-emitting element is any one of the following: circle, ellipse, triangle, rhombus, rectangle, and regular polygon;

[0037] The light-receiving area of ​​the photoelectric conversion element can be any shape among square, circle, and regular polygon.

[0038] In some embodiments, the light-emitting area of ​​the second light-emitting element is elongated, and the length direction of the elongated shape is along the second direction.

[0039] In some embodiments, a color filter layer is further included, located on the light-emitting side of the repeating unit;

[0040] The color filter layer includes a color filter and a black matrix;

[0041] The display substrate further includes a substrate and a pixel defining layer disposed on the substrate;

[0042] The pixel defining layer has multiple openings, and the first light-emitting element, the second light-emitting element, the third light-emitting element and the photoelectric conversion element are respectively located in the openings one by one;

[0043] The first light-emitting element is a red light-emitting element; the second light-emitting element is a green light-emitting element; and the third light-emitting element is a blue light-emitting element.

[0044] The color resist includes red, green, and blue color resists;

[0045] The orthographic projection of the red color resist on the substrate overlaps with the light-emitting area of ​​the first light-emitting element; the orthographic projection of the green color resist on the substrate overlaps with the light-emitting area of ​​the second light-emitting element; the orthographic projection of the blue color resist on the substrate overlaps with the light-emitting area of ​​the third light-emitting element.

[0046] The orthographic projection of the black matrix onto the substrate overlaps with the pixel defining layer.

[0047] In some embodiments, within the region where the repeating unit is located, the width of the black matrix is ​​consistent, and the width of the black matrix is ​​smaller than the width of the pixel delimiting layer.

[0048] In some embodiments, in the overlapping region of the orthographic projection of the black matrix and the pixel delimiting layer, the black matrix has a first orthographic projection boundary and a second orthographic projection boundary in its width direction; the pixel delimiting layer has a third orthographic projection boundary and a fourth orthographic projection boundary in its width direction.

[0049] The first orthographic projection boundary and the third orthographic projection boundary are located at one end of the black matrix along its width direction; the second orthographic projection boundary and the fourth orthographic projection boundary are located at the other end of the black matrix along its width direction.

[0050] The distance between the first orthographic projection boundary and the third orthographic projection boundary is equal to the distance between the second orthographic projection boundary and the fourth orthographic projection boundary.

[0051] Secondly, embodiments of this disclosure also provide a method for preparing a display substrate, comprising: vapor deposition to form a first light-emitting element, a second light-emitting element, a third light-emitting element, and a photoelectric conversion element in a repeating unit.

[0052] In some embodiments, the two second light-emitting elements in the repeating unit are simultaneously vapor-deposited through a mask opening on a metal mask plate.

[0053] In some embodiments, the two photoelectric conversion elements in the repeating unit are simultaneously vapor-deposited through two mask openings on a metal mask plate.

[0054] Thirdly, embodiments of this disclosure also provide a display panel, which includes the aforementioned display substrate.

[0055] Fourthly, embodiments of this disclosure also provide a display device, which includes the aforementioned display panel. Attached Figure Description

[0056] The accompanying drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. The above and other features and advantages will become more apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0057] Figure 1 This is a top view of a repeating unit in a display substrate provided in an embodiment of the present disclosure.

[0058] Figure 2 Another top view of a repeating unit in a display substrate provided in an embodiment of this disclosure.

[0059] Figure 3 This is a top view of the repeating unit arrangement in a display substrate provided in an embodiment of this disclosure.

[0060] Figure 4 Another top view of the repeating unit arrangement in the display substrate provided in the embodiments of this disclosure.

[0061] Figure 5 This is another top view of the repeating unit arrangement in the display substrate provided in the embodiments of this disclosure.

[0062] Figure 6 A schematic diagram illustrating the principle of fingerprint recognition using photoelectric conversion elements.

[0063] Figure 7 for Figure 3 A cross-sectional view of the display substrate along the AA' section line.

[0064] Figure 8This is a schematic diagram of the identification area of ​​the photoelectric conversion element in an embodiment of this disclosure.

[0065] Figure 9 This is a schematic diagram of the arrangement of photoelectric conversion elements in the disclosed technology. Detailed Implementation

[0066] To enable those skilled in the art to better understand the technical solutions of the embodiments of this disclosure, the following describes in further detail a display substrate and its preparation method, a display panel, and a display device provided by the embodiments of this disclosure, in conjunction with the accompanying drawings and specific implementation methods.

[0067] Embodiments of this disclosure will be described more fully below with reference to the accompanying drawings; however, the embodiments shown may be embodied in different forms and should not be construed as limited to the embodiments set forth in this disclosure. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will enable those skilled in the art to fully understand the scope of this disclosure.

[0068] This disclosure is not limited to the embodiments shown in the accompanying drawings, but includes modifications to the configuration based on the manufacturing process. Therefore, the areas illustrated in the drawings are schematic, and the shapes of the areas shown illustrate specific shapes of the areas, but are not intended to be limiting.

[0069] Fingerprints are innate and unique to each individual. With market development, fingerprint recognition technology has become an important function of electronic products. This function has attracted the attention of many electronics manufacturers and has been applied to their products, such as mobile phones, tablets, and smart wearable devices. Thus, before operating an electronic device with fingerprint recognition, users only need to touch the fingerprint recognition module of the device with their finger to complete the authorization verification process, simplifying the authorization verification process.

[0070] Currently, fingerprint recognition solutions include capacitive, optical diode, and organic photoelectric (OPD) sensors. OPD sensors offer high photoresponse, enabling high-resolution full-screen fingerprint recognition, and their narrow response wavelength makes them less susceptible to ambient light. Integrating OPD sensors into OLED display panels to achieve the detection and recognition of biometric information such as fingerprints has become a popular technological trend.

[0071] In publicly available technologies, optical fingerprint recognition technology using organic photoelectric sensors is combined with display technology, allowing the fingerprint recognition area to be located within the display area. This solves the problem of low screen-to-body ratio caused by placing the fingerprint recognition area in a non-display area. However, since organic photoelectric sensors are fabricated in the display area using a vapor deposition process, some pixel aperture ratio of the display panel needs to be sacrificed. This reduces the lifespan of the OLED display panel. Therefore, the pixel design of OLED display panels integrating organic photoelectric sensors to meet product requirements has become a current focus of attention.

[0072] Currently, to ensure the display performance of OLED display panels integrating organic photoelectric sensors, a color filter layer is typically placed on the light-emitting side of the OLED display panel. This color filter layer includes a color resist (CF) and a black matrix (BM), where different colored CFs correspond to different colored OLED light-emitting elements, and the black matrix corresponds to the pixel boundary layer. The pixel boundary layer defines the deposition position of the OLED light-emitting elements. In an OLED display panel, assuming the BM OUT value (i.e., at the corresponding overlapping positions of the black matrix and pixel boundary layer, the horizontal distance between the two width boundaries of the black matrix and the corresponding two width boundaries of the pixel boundary layer is equal), the width of the emitting area of ​​different colored OLED light-emitting elements is affected differently by the black matrix, and this influence is negatively correlated with the width of the emitting area of ​​the OLED light-emitting element. Therefore, the arrangement of different colored OLED light-emitting elements in an OLED display panel integrating organic photoelectric sensors has varying degrees of compatibility with OLED display panels equipped with a color filter layer. Therefore, the design needs to consider how the arrangement of OLED light-emitting elements can achieve better optical effects; for OLED display panels that integrate organic photoelectric sensors, it is also necessary to consider how to reduce the influence of the color filter layer on the emitted light of OLED display panels with color filter layers, so as to better realize the fingerprint recognition function of organic photoelectric sensors.

[0073] To address the aforementioned problems, in a first aspect, this disclosure provides a display substrate, referring to... Figures 1-5 , Figure 1 A top view of a repeating unit in a display substrate provided in an embodiment of this disclosure; Figure 2 Another top view of a repeating unit in a display substrate provided in an embodiment of this disclosure; Figure 3 A top view of the repeating unit arrangement in a display substrate provided in an embodiment of this disclosure; Figure 4 Another top view of the repeating unit arrangement in the display substrate provided in the embodiments of this disclosure; Figure 5This is another top view of the repeating unit arrangement in a display substrate provided in this embodiment. The display substrate includes: a plurality of repeating units 1; each repeating unit 1 includes a first light-emitting element 11, a second light-emitting element 12, a third light-emitting element 13, and a photoelectric conversion element 10; the number of first light-emitting elements 11 and third light-emitting elements 13 is the same; the number of second light-emitting elements 12 and photoelectric conversion elements 10 is the same; the number of second light-emitting elements 12 is twice the number of first light-emitting elements 11; the first light-emitting elements 11, second light-emitting elements 12, and third light-emitting elements 13 are arranged sequentially along a first direction X; the second light-emitting elements 12 are arranged sequentially along a second direction Y; the photoelectric conversion elements 10 are arranged sequentially along the second direction Y; the first direction X and the second direction Y form an angle greater than 0° and less than or equal to 90°; the photoelectric conversion elements 10 and the second light-emitting elements 12 are adjacent and distributed in a one-to-one correspondence; any corresponding group of second light-emitting elements 12 and photoelectric conversion elements 10 are arranged along the first direction X; the first light-emitting element 11 is located between two adjacent photoelectric conversion elements 10; or, the third light-emitting element 13 is located between two adjacent photoelectric conversion elements 10.

[0074] In some embodiments, in the repeating unit 1, there is one first light-emitting element 11; there are two second light-emitting elements 12; the two second light-emitting elements 12 are respectively disposed on the upper and lower sides of the line connecting the center of the light-emitting area of ​​the first light-emitting element 11 and the center of the light-emitting area of ​​the third light-emitting element 13; the two photoelectric conversion elements 10 are respectively disposed on the upper and lower sides of the line connecting the center of the light-emitting area of ​​the first light-emitting element 11 and the center of the light-emitting area of ​​the third light-emitting element 13.

[0075] Among them, reference Figure 6 This is a schematic diagram illustrating the principle of fingerprint recognition using a photoelectric conversion element. The photoelectric conversion element 10 can be an organic photoelectric conversion element; the photoelectric conversion element 10 can receive light emitted by different colored light-emitting elements reflected from the fingerprint ridges and convert the light into an electrical signal for output, thereby realizing fingerprint detection.

[0076] In some embodiments, refer to Figure 7 ,for Figure 3The diagram shows a cross-sectional view of the display substrate along the AA' section line. The display substrate also includes a color filter layer 2 located on the light-emitting side of the repeating unit 1; the color filter layer 2 includes a color resist and a black matrix 20; the display substrate also includes a substrate 3 and a pixel defining layer 4 disposed on the substrate 3; the pixel defining layer 4 has multiple openings, and a first light-emitting element 11, a second light-emitting element 12, a third light-emitting element 13, and a photoelectric conversion element 10 are respectively located in the openings; the first light-emitting element 11 is a red light-emitting element; the second light-emitting element 12 is a green light-emitting element; the third light-emitting element 13 is a blue light-emitting element; the color resist includes a red color resist 21, a green color resist 22, and a blue color resist; the orthographic projection of the red color resist 21 on the substrate 3 overlaps with the light-emitting area of ​​the first light-emitting element 11; the orthographic projection of the green color resist 22 on the substrate 3 overlaps with the light-emitting area of ​​the second light-emitting element 12; the orthographic projection of the blue color resist on the substrate 3 overlaps with the light-emitting area of ​​the third light-emitting element 13; the orthographic projection of the black matrix 20 on the substrate 3 overlaps with the pixel defining layer 4.

[0077] In some embodiments, the display substrate further includes an encapsulation layer 5, which is located between the color filter layer 2 and the light-emitting elements of different colors. The encapsulation layer 5 is used to encapsulate the light-emitting elements of different colors and the photoelectric conversion element 10 to prevent external water and oxygen from intruding and damaging the light-emitting elements.

[0078] The setting of different color resists in the color filter layer 2 can improve the display color gamut and color purity of the display substrate; the setting of the black matrix 20 in the color filter layer 2 can form a first light collimation hole corresponding to the different color light-emitting elements on the side away from the substrate 3, so that the light emitted by the different color light-emitting elements can be collimated and emitted or irradiated onto the fingerprint after passing through the first light collimation hole corresponding to it; at the same time, a second light collimation hole corresponding to the photoelectric conversion element 10 can be formed on the side away from the substrate 3, so that the light reflected by the fingerprint can be irradiated onto the photoelectric conversion element 10 after passing through the second light collimation hole. The first collimating aperture can block stray light other than the collimated light emitted by different color light-emitting elements or the collimated light that illuminates the fingerprint; the second collimating aperture can block stray light other than the collimated light that enters the photoelectric conversion element 10 after being reflected by the fingerprint; thereby improving the fingerprint detection accuracy of the photoelectric conversion element 10. In addition, the black matrix 20 can also block stray light emitted by different color light-emitting elements that directly illuminates the photoelectric conversion element 10 without fingerprint reflection. This stray light is reflected by the black matrix 20 and then illuminates the fingerprint, and after being reflected by the fingerprint, it illuminates the photoelectric conversion element 10 again, thereby increasing the incident amount of fingerprint reflected light on the photoelectric conversion element 10, and thus improving the fingerprint detection accuracy and detection efficiency of the photoelectric conversion element 10. Therefore, the setting of the color filter layer 2 not only improves the display effect of the display substrate, but also improves the fingerprint detection accuracy and detection efficiency of the photoelectric conversion element 10, enabling more accurate fingerprint recognition and meeting the requirements of more secure fingerprint payment.

[0079] In some embodiments, within the region where the repeating unit 1 is located, the width of the black matrix 20 is consistent, and the width of the black matrix 20 is smaller than the width of the pixel delimiting layer 4.

[0080] In some embodiments, in the overlapping area of ​​the orthographic projections of the black matrix 20 and the pixel defining layer 4, the black matrix 20 has a first orthographic projection boundary and a second orthographic projection boundary in its width direction; the pixel defining layer 4 has a third orthographic projection boundary and a fourth orthographic projection boundary in its width direction; the first and third orthographic projection boundaries are located at one end of the black matrix 20 along its width direction; the second and fourth orthographic projection boundaries are located at the other end of the black matrix 20 along its width direction; the distance a1 between the first and third orthographic projection boundaries is equal to the distance a2 between the second and fourth orthographic projection boundaries. This configuration can improve or avoid the problem of the black matrix 20 having different degrees of influence on the width of the light-emitting areas of different color light-emitting elements, thereby improving the display effect of the display substrate.

[0081] In some embodiments, the light-emitting elements of different colors each include a first electrode 101, a hole transport layer 102, a light-emitting layer 103, an electron transport layer 104, and a second electrode 105 sequentially stacked on the substrate 3. The photoelectric conversion element 10 includes a third electrode 106, a hole transport layer 102, a photoelectric conversion layer 107, an electron transport layer 104, and a second electrode 105 sequentially stacked on the substrate 3. The hole transport layer 102, electron transport layer 104, and second electrode 105 of the light-emitting element and the hole transport layer 102, electron transport layer 104, and second electrode 105 of the photoelectric conversion element 10 are covered by the same film layer, that is, in order to simplify the manufacturing process, the three film layers of the light-emitting element and the photoelectric conversion element 10 can be shared separately.

[0082] In some embodiments, the substrate 3 includes a pixel driving circuit and a photoelectric conversion output circuit. The pixel driving circuit includes a plurality of first switching transistors 31, one of which is connected to the first electrode 101 of the light-emitting element as a driving transistor to drive the light-emitting element to emit light. The photoelectric conversion output circuit includes a second switching transistor 32, which is connected to the photoelectric conversion element 10 and is used to output the current signal converted by the photoelectric conversion element 10.

[0083] In some embodiments, in the repeating unit 1, the distance b1 between the center of the light-emitting region of the two second light-emitting elements 12 and the line connecting the center of the light-emitting region of the first light-emitting element 11 and the center of the light-emitting region of the third light-emitting element 13 is equal; the distance b2 between the center of the light-receiving region of the two photoelectric conversion elements 10 and the line connecting the center of the light-emitting region of the first light-emitting element 11 and the center of the light-emitting region of the third light-emitting element 13 is equal.

[0084] The light-emitting area of ​​the light-emitting element refers to the opening area in the pixel defining layer 4 where the light-emitting element is located; the center of the light-emitting area is the geometric center of a regularly shaped light-emitting area or the centroid of an irregularly shaped light-emitting area. The light-receiving area of ​​the photoelectric conversion element 10 refers to the opening area in the pixel defining layer 4 where the photoelectric conversion element 10 is located; the center of the light-receiving area is the geometric center of a regularly shaped light-receiving area or the centroid of an irregularly shaped light-receiving area.

[0085] In some embodiments, the first direction X is perpendicular to the second direction Y; in the repeating unit 1, the distance c1 between the center of the light-emitting area of ​​a corresponding set of second light-emitting elements 12 and the center of the light-receiving area of ​​the photoelectric conversion element 10 is equal to the distance c2 between the center of the light-emitting area of ​​another corresponding set of second light-emitting elements 12 and the center of the light-receiving area of ​​the photoelectric conversion element 10. Since the photoelectric conversion element 10 is more sensitive to green light, the distance c1 equal to the distance c2 can make the recognition area P of adjacent photoelectric conversion elements 10 highly overlapped and uniform, thereby improving the fingerprint recognition performance of the photoelectric conversion element 10.

[0086] In some embodiments, in the repeating unit 1, the center of the light-emitting area of ​​the first light-emitting element 11 and the center of the light-emitting area of ​​the third light-emitting element 13 are located on the same straight line along the first direction X. The light-emitting area of ​​the third light-emitting element 13 is larger than the light-emitting area of ​​the second light-emitting element 12, and the light-emitting area of ​​the second light-emitting element 12 is larger than the light-emitting area of ​​the first light-emitting element 11. Since the size of the light-emitting area of ​​the third light-emitting element 13 determines the lifespan of the third light-emitting element 13, and the third light-emitting element 13 has the shortest lifespan compared to other color light-emitting elements, this arrangement can improve the lifespan of different color light-emitting elements, thereby improving the lifespan of the display substrate.

[0087] In some embodiments, the light-emitting area of ​​the first light-emitting element 11 has a first maximum width R1 along the first direction X and a second maximum width R2 along the second direction Y; 0.67 ≤ first maximum width R1 / second maximum width R2 ≤ 1.5; first maximum width R1 ≥ 20 μm; second maximum width R2 ≥ 20 μm. This width setting of the first light-emitting element 11 can reduce the difference in display width between the horizontal lines along the first direction X and the vertical lines along the second direction Y on the display substrate.

[0088] In some embodiments, the light-emitting region of the third light-emitting element 13 has a third maximum width B1 along the first direction X and a fourth maximum width B2 along the second direction Y; 0.67 ≤ third maximum width B1 / fourth maximum width B2 ≤ 1.5; third maximum width B1 ≥ 20 μm; fourth maximum width B2 ≥ 20 μm.

[0089] In some embodiments, in the repeating unit 1, the minimum distance d between the light-emitting areas of the two second light-emitting elements 12 is ≥ 20 μm. Here, the minimum distance d is the spacing between adjacent sides of the two second light-emitting elements 12. Setting this minimum distance d can reduce the jagged appearance of the display substrate along the horizontal line of the first direction X, thereby improving the display effect of the display substrate.

[0090] In this embodiment, because the proportion of each color light in white light synthesis makes the effect of changes in blue light, red light and green light on the color shift of white light decrease sequentially, only the width ratio of the first light-emitting element 11 and the third light-emitting element 13 is set. Considering the total aperture ratio of the display substrate, the width ratio of the second light-emitting element 12 is not limited, thereby ensuring a larger aperture ratio of the display substrate and making the photoelectric conversion element 10 more suitable for display substrates with a color filter layer 2.

[0091] In some embodiments, the light-receiving region area of ​​the photoelectric conversion element 10 is greater than 100 μm. 2This allows the photoelectric conversion element 10 to better receive light emitted by light-emitting elements of different colors, thereby achieving more accurate fingerprint recognition and meeting the requirements for more secure fingerprint payment.

[0092] In some embodiments, refer to Figures 3-5 Multiple repeating units 1 are arranged in an array, with the row direction of the array along the first direction X and the column direction along the second direction Y. Each repeating unit 1 in any two adjacent rows of repeating units 1 is located in a different column. The photoelectric conversion elements 10 that are close to each other along the second direction Y in any two adjacent rows of repeating units 1 are located on the same straight line along the first direction X. The m-th repeating unit 1 in the n-th row and the (n+2)-th row of repeating units 1 are located on the same straight line along the second direction Y. Where n = 1, 2, 3, ... and n is an integer; m = 1, 2, 3, ... and m is an integer. In the array, the distance e1 between any two adjacent photoelectric conversion elements 10 located on the same straight line along the second direction Y is equal to the distance e2 between any two adjacent photoelectric conversion elements 10 located on the same straight line along the first direction X.

[0093] Wherein, spacing e1 and spacing e2 are the distance between the centers of the light-receiving regions of the two photoelectric conversion elements 10. It should be noted that for photoelectric conversion elements 10 with regularly shaped light-receiving regions, spacing e1 and spacing e2 can also be the distance between adjacent sides of the two photoelectric conversion elements 10.

[0094] Reference Figure 8 This is a schematic diagram of the identification area of ​​the photoelectric conversion element in an embodiment of this disclosure; Figure 9 This is a schematic diagram of the arrangement of photoelectric conversion elements in the disclosed technology; the above-mentioned arrangement and spacing of the photoelectric conversion elements 10 in the repeating unit 1 array enables the recognition areas P of adjacent photoelectric conversion elements 10 to have a high degree of overlap and uniformity, thereby improving the fingerprint recognition performance of the photoelectric conversion elements 10; at the same time, it enables the photoelectric conversion elements 10 to better receive light emitted by different color light-emitting elements, so as to achieve more accurate fingerprint recognition function and meet the requirements of more secure fingerprint payment. In the disclosed technology, such as... Figure 9 As shown, the spacing e2 is much larger than the spacing e1, which makes the photoelectric conversion element 10 unable to meet the requirements of more secure fingerprint payment.

[0095] In some embodiments, refer to Figure 4In two adjacent repeating units 1, and in two adjacent repeating units 1 located in different rows, the distance f1 (f2) between the center of the light-receiving area of ​​the photoelectric conversion element 10 located between two adjacent second light-emitting elements 12 along the first direction X and the center of the light-emitting area of ​​the two second light-emitting elements 12 is equal. Specifically, the distance f1 (f2) can be equalized by rotating the photoelectric conversion element 10 by a certain angle (e.g., 60°) and / or finely adjusting the position of the photoelectric conversion element 10. Since the photoelectric conversion element 10 is more sensitive to green light, the equal distance f1 (f2) can make the recognition area P of adjacent photoelectric conversion elements 10 highly overlapped and uniform, thereby improving the fingerprint recognition performance of the photoelectric conversion element 10.

[0096] In some embodiments, the photoelectric conversion element 10 includes a functional layer; the first light-emitting element 11 and the third light-emitting element 13 each include a light-emitting layer; at least one edge of the functional layer is parallel to at least one edge of the light-emitting layer of the adjacent first light-emitting element 11 or third light-emitting element 13. This configuration can increase the aperture ratio of the light-emitting element, thereby increasing the display aperture ratio of the display substrate.

[0097] In some embodiments, the shape of the light-emitting area of ​​the first light-emitting element 11 is any one of a circle, ellipse, triangle, rhombus, rectangle, or regular polygon; the shape of the light-emitting area of ​​the third light-emitting element 13 is any one of a circle, ellipse, triangle, rhombus, rectangle, or regular polygon; and the shape of the light-receiving area of ​​the photoelectric conversion element 10 is any one of a square, circle, or regular polygon.

[0098] In this embodiment, the light-emitting areas of the first light-emitting element 11 and the third light-emitting element 13 are both elliptical or rectangular; the light-receiving area of ​​the photoelectric conversion element 10 is square.

[0099] In some embodiments, the light-emitting area of ​​the second light-emitting element 12 is elongated, and the length direction of the elongated shape is along the second direction Y.

[0100] The different colored light-emitting elements and photoelectric conversion elements 10 with the aforementioned light-emitting area shapes can be tightly nested together, thereby increasing the display aperture ratio of the display substrate and thus improving the service life of the display substrate.

[0101] In some embodiments, the angular shapes of the first light-emitting element 11, the second light-emitting element 12, the third light-emitting element 13, and the photoelectric conversion element 10 can be rounded or have a certain degree of curvature in the actual product after manufacturing. This arrangement also facilitates the tight nesting of different color light-emitting elements and photoelectric conversion elements 10, thereby increasing the display aperture ratio of the display substrate and thus improving the service life of the display substrate.

[0102] In this embodiment, the quantity and arrangement of different color light-emitting elements and photoelectric conversion elements 10 in the repeating unit 1 achieve, on the one hand, high-resolution display of the display substrate; on the other hand, it enables the photoelectric conversion elements 10 to better receive the light emitted by different color light-emitting elements, thereby achieving more accurate fingerprint recognition and meeting more secure fingerprint payment requirements; furthermore, for display substrates with a color filter layer, the repeating unit 1 reduces the influence of the color filter layer on the light emitted by different color light-emitting elements, thereby better realizing the fingerprint recognition function of the photoelectric conversion elements 10; and yet another aspect, the repeating unit 1 ensures a large aperture ratio of the display substrate, and the openings on the metal mask used for vapor deposition to form different color light-emitting elements and photoelectric conversion elements 10 are regular, facilitating the meshing and use of the metal mask, and improving product yield and performance.

[0103] Secondly, this disclosure also provides a method for preparing the above-mentioned display substrate, which includes: vapor deposition to form a first light-emitting element, a second light-emitting element, a third light-emitting element, and a photoelectric conversion element in a repeating unit.

[0104] In this process, the film layers of different color light-emitting elements and the film layers of photoelectric conversion elements can be prepared by vapor deposition. In some embodiments, the hole transport layer, electron transport layer and second electrode of different color light-emitting elements and photoelectric conversion elements can be prepared by a single vapor deposition process. The first electrode of different color light-emitting elements and the third electrode of photoelectric conversion elements can also be prepared by a single vapor deposition process or a patterning process, which simplifies the fabrication process of the display substrate.

[0105] In some embodiments, the two second light-emitting elements in the repeating unit are simultaneously vapor-deposited through a mask opening on a metal mask. This increases the aperture ratio of the second light-emitting elements on the display substrate, thereby reducing the impact of blue and red light variations on white light color shift and improving the display effect of the display substrate. Simultaneously, the second light-emitting elements in the repeating unit can be fabricated in a single masking process, simplifying the fabrication process of the second light-emitting elements.

[0106] In some embodiments, the two photoelectric conversion elements in the repeating unit are simultaneously deposited through two mask openings on a metal mask. This fabrication method, on the one hand, avoids the two photoelectric conversion elements in the repeating unit from obstructing the first or third light-emitting element located between them during fabrication, thereby ensuring the resolution of the display substrate; on the other hand, compared to the disclosed method of simultaneously depositing two photoelectric conversion elements through one mask opening on a metal mask, it increases the number of photoelectric conversion elements distributed on the display substrate, thereby achieving more accurate fingerprint recognition and meeting more secure fingerprint payment requirements.

[0107] Thirdly, embodiments of this disclosure also provide a display panel, including the display substrate described in the above embodiments.

[0108] By using the display substrate in the above embodiments, on the one hand, high-resolution display of the display panel can be achieved; on the other hand, more accurate fingerprint recognition function of the display panel can be achieved and more secure fingerprint payment requirements can be met; furthermore, the display effect of the display panel can be improved; and yet another aspect is that the display panel has a larger aperture ratio, better yield, and better performance.

[0109] Fourthly, embodiments of this disclosure also provide a display device, including the display panel described in the above embodiments.

[0110] By adopting the display panel in the above embodiments, on the one hand, the display device can achieve high-resolution display; on the other hand, the display device can achieve more accurate fingerprint recognition function and meet more secure fingerprint payment requirements; furthermore, the display effect of the display device can be improved; and yet another aspect is that the display device has a larger aperture ratio, better yield, and better performance.

[0111] The display device can be any product or component with display function, such as an OLED panel, OLED TV, mobile phone, tablet computer, laptop computer, monitor, digital photo frame, or navigator.

[0112] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A display substrate, comprising: a plurality of repeating units; the repeating unit comprises a first light emitting element, a second light emitting element, a third light emitting element, and a photoelectric conversion element; the number of the first light emitting elements is the same as that of the third light emitting elements; the number of the second light emitting elements is the same as that of the photoelectric conversion elements; the number of the second light emitting elements is twice the number of the first light emitting elements; the first light emitting elements, the second light emitting elements, and the third light emitting elements are arranged in sequence along a first direction; the second light emitting elements are arranged in sequence along a second direction; the photoelectric conversion elements are arranged in sequence along the second direction; an included angle between the first direction and the second direction is greater than 0° and less than or equal to 90°; the photoelectric conversion elements are distributed adjacent to and one-to-one corresponding to the second light emitting elements; any corresponding group of the second light emitting elements and the photoelectric conversion elements is arranged along the first direction; the first light emitting elements or the third light emitting elements are located between two adjacent photoelectric conversion elements. 2.The display substrate of claim 1, wherein, in the repeating unit, the first light emitting element is one; the number of the second light emitting elements is two; the two second light emitting elements are respectively arranged on the upper and lower sides of a line connecting the light emitting region center of the first light emitting element and the light emitting region center of the third light emitting element; the two photoelectric conversion elements are respectively arranged on the upper and lower sides of a line connecting the light emitting region center of the first light emitting element and the light emitting region center of the third light emitting element. 3.The display substrate of claim 2, wherein, in the repeating unit, the distance between the light emitting region center of the two second light emitting elements and the line connecting the light emitting region center of the first light emitting element and the light emitting region center of the third light emitting element is equal; the distance between the light receiving region center of the two photoelectric conversion elements and the line connecting the light emitting region center of the first light emitting element and the light emitting region center of the third light emitting element is equal. 4.The display substrate of claim 3, wherein, the first direction is perpendicular to the second direction; in the repeating unit, the distance between the light emitting region center of the corresponding group of the second light emitting elements and the light receiving region center of the photoelectric conversion element is equal to the distance between the light emitting region center of the other corresponding group of the second light emitting elements and the light receiving region center of the photoelectric conversion element.

5. The display substrate according to any one of claims 2-4, wherein, in the repeating unit, the light emitting region center of the first light emitting element and the light emitting region center of the third light emitting element are located on the same straight line along the first direction. 6.The display substrate of claim 5, wherein, the light emitting region of the first light emitting element has a first maximum width along the first direction and a second maximum width along the second direction; 0.67 ≤ the first maximum width / the second maximum width ≤ 1.5; the first maximum width ≥ 20 µm; the second maximum width ≥ 20 µm. 7.The display substrate of claim 6, wherein, the light emitting region of the third light emitting element has a third maximum width along the first direction and a fourth maximum width along the second direction; 0.67 ≤ the third maximum width / the fourth maximum width ≤ 1.5; the third maximum width ≥ 20 µm; the fourth maximum width ≥ 20 µm. 8.The display substrate of claim 7, wherein, in the repeating unit, the minimum distance between the light emitting regions of the two second light emitting elements is ≥ 20 µm. 9.The display substrate of claim 8, wherein, The light-receiving region area of the photoelectric conversion element is greater than 100 µm 2 .

10. The display substrate according to any one of claims 6-9, wherein, The plurality of repeating units are arranged in an array, a row direction of the array is along the first direction, and a column direction of the array is along the second direction; Each of the repeating units in any two adjacent rows is located in a different column, respectively; The photoelectric conversion elements in any two adjacent rows of the repeating units and close to each other in the second direction are located on the same straight line in the first direction; The mth repeating unit in the nth row and the nth+2 row of the repeating units is located on the same straight line in the second direction; wherein, n = 1, 2, 3…, and n is an integer; m = 1, 2, 3…, and m is an integer; In the array, the spacing between any two adjacent photoelectric conversion elements located on the same straight line in the second direction is equal to the spacing between any two adjacent photoelectric conversion elements located on the same straight line in the first direction. 11.The display substrate of claim 10, wherein, In the two adjacent rows of the repeating units and the two adjacent repeating units located in different rows, respectively, the spacing between the light receiving area center of the photoelectric conversion element located adjacent to each other in the first direction and the light emitting area center of the two second light emitting elements is equal. 12.The display substrate of claim 10, wherein, The photoelectric conversion element comprises a functional layer; The first light emitting element and the third light emitting element each comprise a light emitting layer; At least one side of the functional layer is parallel to at least one side of the light emitting layer of the adjacent first light emitting element or third light emitting element. 13.The display substrate of claim 1, wherein, The light emitting area of the first light emitting element is in any one of a circular shape, an elliptical shape, a triangular shape, a diamond shape, a rectangular shape, and a regular polygon shape. The light emitting area of the third light emitting element is in any one of a circular shape, an elliptical shape, a triangular shape, a diamond shape, a rectangular shape, and a regular polygon shape. The light receiving area of the photoelectric conversion element is in any one of a square shape, a circular shape, and a regular polygon shape. 14.The display substrate of claim 1, wherein, The light emitting area of the second light emitting element is in a strip shape, and the length direction of the strip shape is along the second direction. 15.The display substrate of claim 1, wherein, Further comprising a color filter layer located on the light emitting side of the repeating unit; The color filter layer comprises color resist and a black matrix; The display substrate further comprises a substrate and a pixel definition layer disposed on the substrate; The pixel definition layer has a plurality of openings, and the first light emitting element, the second light emitting element, the third light emitting element, and the photoelectric conversion element are located in the openings one by one; The first light emitting element is a red light emitting element; the second light emitting element is a green light emitting element; and the third light emitting element is a blue light emitting element; The color resist comprises red color resist, green color resist, and blue color resist; The red color resist has a projection on the substrate that overlaps the light emitting area of the first light emitting element; the green color resist has a projection on the substrate that overlaps the light emitting area of the second light emitting element; and the blue color resist has a projection on the substrate that overlaps the light emitting area of the third light emitting element; The black matrix has a projection on the substrate that overlaps the pixel definition layer. 16.The display substrate of claim 15, wherein, In the area where the repeating unit is located, the width of the black matrix is uniform, and the width of the black matrix is smaller than the width of the pixel definition layer. 17.The display substrate of claim 16, wherein, The black matrix has a first orthogonal projection boundary and a second orthogonal projection boundary in a width direction thereof in the overlapping area of the orthogonal projection of the black matrix and the pixel definition layer; the pixel definition layer has a third orthogonal projection boundary and a fourth orthogonal projection boundary in a width direction thereof; The first orthogonal projection boundary and the third orthogonal projection boundary are located at one end of the black matrix along the width direction thereof; the second orthogonal projection boundary and the fourth orthogonal projection boundary are located at the other end of the black matrix along the width direction thereof; The distance between the first orthogonal projection boundary and the third orthogonal projection boundary is equal to the distance between the second orthogonal projection boundary and the fourth orthogonal projection boundary.

18. A method for manufacturing a display substrate, wherein The display substrate comprises: The first light emitting element, the second light emitting element, the third light emitting element and the photoelectric conversion element are formed by evaporation in a repeating unit; The number of the first light emitting elements is equal to the number of the third light emitting elements; the number of the second light emitting elements is equal to the number of the photoelectric conversion elements; the number of the second light emitting elements is twice the number of the first light emitting elements; The first light emitting element, the second light emitting element and the third light emitting element are arranged in sequence along a first direction; the second light emitting elements are arranged in sequence along a second direction; the photoelectric conversion elements are arranged in sequence along the second direction; An included angle between the first direction and the second direction is greater than 0° and less than or equal to 90°; The photoelectric conversion elements are adjacent to and one-to-one corresponding to the second light emitting elements; any corresponding group of the second light emitting elements and the photoelectric conversion elements is arranged along the first direction; the first light emitting element or the third light emitting element is located between two adjacent photoelectric conversion elements.

19. The method of manufacturing the display substrate according to claim 18, wherein, In the repeating unit, the number of the first light emitting elements is one; the number of the second light emitting elements is two; The two second light emitting elements in the repeating unit are formed by evaporation through one mask opening on a metal mask plate at the same time; The two second light emitting elements are separately arranged on the upper and lower sides of a line connecting the light emitting area center of the first light emitting element and the light emitting area center of the third light emitting element.

20. The method of manufacturing the display substrate according to claim 19, wherein, The two photoelectric conversion elements in the repeating unit are formed by evaporation through two mask openings on a metal mask plate at the same time; The two photoelectric conversion elements are separately arranged on the upper and lower sides of a line connecting the light emitting area center of the first light emitting element and the light emitting area center of the third light emitting element.

21. A display panel, wherein, The display substrate comprises any one of claims 1-17.

22. A display device comprising: The display panel comprises claim 21.

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