Display panel and preparation method therefor, and display apparatus

Abstract

Provided in the present disclosure are a display panel and a preparation method therefor, and a display apparatus. The display panel comprises a driving backplane (110), wherein a plurality of sub-pixels that emit light in different colors are formed on one side of the driving backplane (110). Each sub-pixel comprises a pixel definition layer (PDL), wherein the PDL is located on one side of the driving backplane (110) and has a pixel opening, and a light-emitting functional layer of the sub-pixel is formed in the pixel opening. The display panel further comprises a plurality of light absorption structures (120), which are arranged corresponding to at least some of the sub-pixels, wherein the light absorption structures (120) are located on the PDLs and are arranged around the sub-pixels, which correspond thereto, in the peripheral direction, the minimum light absorption wavelength of each light absorption structure (120) is less than or equal to the minimum light emission wavelength of the sub-pixel corresponding thereto, and the maximum light absorption wavelength of each light absorption structure (120) is greater than or equal to the maximum light emission wavelength of the sub-pixel corresponding thereto.

Description

Display panel, manufacturing method thereof, and display device

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application number 202310788053.3 filed on June 29, 2023, entitled “A display panel, a method for preparing the same, and a display device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a display panel and a manufacturing method thereof, and a display device. Background Art

[0004] Active matrix organic electroluminescent device (AMOLED) is a new generation of new display technology with huge application prospects. OLED display devices are self-luminous and have the advantages of low driving voltage, high luminous efficiency, short response time, high clarity and contrast, nearly 180° viewing angle, wide operating temperature range and transparent preparation. They can realize flexible display and large-area full-color display. AMOLED is composed of three primary colors RGB to form array sub-pixels, and displays different chromaticities by controlling the luminous brightness of RGB sub-pixels. Usually, the terminal device installs an ambient light sensor on the back of the AMOLED panel to sense the brightness of the user's usage scene, so as to automatically adjust the display brightness of the terminal device, protect the user's eyesight and reduce its own power consumption. In the related technology, there is a problem of low sensing accuracy.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art and to provide a display panel and a manufacturing method thereof, and a display device.

[0008] According to one aspect of the present disclosure, a display panel is provided, comprising: a driving backplane, wherein a plurality of sub-pixels emitting light of different colors are formed on one side of the driving backplane; a pixel defining layer, located on one side of the driving backplane, the pixel defining layer having a pixel opening, and a light-emitting functional layer of the sub-pixel is formed in the pixel opening; and a plurality of light-absorbing structures, arranged corresponding to at least some of the sub-pixels, the light-absorbing structures being located in the pixel defining layer and circumferentially arranged around the corresponding pixel openings, the minimum light-absorbing wavelength of the light-absorbing structures being less than or equal to the minimum light-emitting wavelength of the sub-pixels corresponding thereto, and the maximum light-absorbing wavelength of the light-absorbing structures being greater than or equal to the maximum light-emitting wavelength of the sub-pixels corresponding thereto.

[0009] In an exemplary embodiment of the present disclosure, the display panel has a photosensitive area, and the photosensitive area has a photosensor; wherein the light absorption structure is arranged corresponding to at least part of the sub-pixels in the photosensitive area.

[0010] In an exemplary embodiment of the present disclosure, the photosensitive area includes an R sub-pixel, a G sub-pixel and a B sub-pixel, and the light absorption structure includes a first light absorption structure; the first light absorption structure is arranged corresponding to at least part of the G sub-pixels, the minimum light absorption wavelength of the first light absorption structure is less than or equal to the minimum light emission wavelength of the G sub-pixel, and the maximum light absorption wavelength of the first light absorption structure is greater than or equal to the maximum light emission wavelength of the G sub-pixel.

[0011] In an exemplary embodiment of the present disclosure, the minimum absorption wavelength of the first light absorption structure is also less than or equal to the minimum emission wavelength of the B sub-pixel, and the maximum absorption wavelength of the first light absorption structure is also greater than or equal to the maximum emission wavelength of the B sub-pixel.

[0012] In an exemplary embodiment of the present disclosure, the photosensitive area includes R sub-pixels, G sub-pixels and B sub-pixels, and the light absorption structure includes two light absorption structures among a first light absorption structure, a second light absorption structure and a third light absorption structure; wherein, the first light absorption structure is arranged corresponding to at least part of the G sub-pixels, the second light absorption structure is arranged corresponding to at least part of the R sub-pixels, and the third light absorption structure is arranged corresponding to at least part of the B sub-pixels.

[0013] In an exemplary embodiment of the present disclosure, the photosensitive area includes R sub-pixels, G sub-pixels and B sub-pixels, and the light absorption structure includes a first light absorption structure, a second light absorption structure and a third light absorption structure; wherein, the first light absorption structure is arranged corresponding to at least part of the G sub-pixels, the second light absorption structure is arranged corresponding to at least part of the R sub-pixels, and the third light absorption structure is arranged corresponding to at least part of the B sub-pixels.

[0014] In an exemplary embodiment of the present disclosure, the first light absorption structure, the second light absorption structure, and the third light absorption structure have the same minimum absorption wavelength and the same maximum absorption wavelength, and the minimum absorption wavelength of any light absorption structure is greater than or equal to the minimum emission wavelength of the B sub-pixel, and the maximum absorption wavelength is also greater than or equal to the maximum emission wavelength of the B sub-pixel.

[0015] In an exemplary embodiment of the present disclosure, the material of the light absorption structure includes a compound represented by the following structural formula (1):

[0016] Alternatively, the light absorption structure is made of a black material.

[0017] In an exemplary embodiment of the present disclosure, the display panel further includes: a first electrode layer, including a plurality of first electrodes distributed in an array, the pixel defining layer having the pixel opening at the first electrode, and the light-emitting functional layer being formed on the side of the first electrode facing away from the driving backplane; wherein the orthographic projection of the light-absorbing structure on the driving backplane at least partially overlaps with the orthographic projection of the first electrode on the driving backplane.

[0018] In an exemplary embodiment of the present disclosure, the display panel further includes: a first electrode layer, including a plurality of first electrodes distributed in an array, the pixel defining layer having the pixel opening at the first electrode, and the light-emitting functional layer being formed on the side of the first electrode facing away from the driving backplane; wherein the orthographic projection of the light-absorbing structure on the driving backplane does not overlap with the orthographic projection of the first electrode on the driving backplane.

[0019] In an exemplary embodiment of the present disclosure, the display panel further includes: a first electrode layer, including a plurality of first electrodes distributed in an array, the pixel defining layer having the pixel opening at the first electrode, and the light-emitting functional layer being formed on a side of the first electrode facing away from the driving backplane; wherein the light absorption structure contacts the side wall of the corresponding first electrode.

[0020] In an exemplary embodiment of the present disclosure, the display panel further includes: a first electrode layer, including a plurality of first electrodes distributed in an array, the pixel defining layer having the pixel opening at the first electrode, and the light-emitting functional layer being formed on the side of the first electrode facing away from the driving backplane; wherein the minimum width of the light absorption structure on the positive projection of the driving backplane is the first width, and there is a gap between the light absorption structure and the corresponding first electrode, and the gap width is less than or equal to the first width.

[0021] In an exemplary embodiment of the present disclosure, a ratio of the gap width to the first width is greater than 0 and less than or equal to 1.

[0022] In an exemplary embodiment of the present disclosure, the light absorption structure penetrates the pixel defining layer in a thickness direction of the driving backplane.

[0023] In an exemplary embodiment of the present disclosure, the light absorption structure has a bottom surface and a top surface arranged opposite to each other in the thickness direction of the driving backplane, the bottom surface is located on the side of the top surface close to the driving backplane, and the pixel defining layer covers the top surface of the light absorption structure.

[0024] In an exemplary embodiment of the present disclosure, the display panel further includes: a second electrode layer, located on the side of the pixel defining layer facing away from the driving backplane, and at least a portion of the pixel defining layer contacts the second electrode layer on one side and contacts the driving backplane on the other side; wherein, in the thickness direction of the driving backplane, the light absorption structure has a first thickness between the top and bottom surfaces, the pixel defining layer has a second thickness at a position contacting the second electrode layer, and the ratio of the first thickness to the second thickness is greater than or equal to 0.6.

[0025] In an exemplary embodiment of the present disclosure, the light-absorbing structure includes a first structural layer and a second structural layer parallel to the driving backplane, and the first structural layer is located at any position on a side of the second structural layer away from the driving backplane; wherein the orthographic projection of the first structural layer on the driving backplane is located within the orthographic projection of the second structure on the driving backplane, or, the orthographic projection of the first structural layer on the driving backplane overlaps with the orthographic projection of the second structure on the driving backplane.

[0026] In an exemplary embodiment of the present disclosure, the light absorption structure includes a first structural layer and a second structural layer parallel to the driving backplane, and the first structural layer is located at any position of the second structural layer on a side away from the driving backplane; wherein the orthographic projection of the second structural layer on the driving backplane is located within the orthographic projection of the first structural layer on the driving backplane.

[0027] In an exemplary embodiment of the present disclosure, the orthographic projection of the light absorption structure on the driving backplate is a circular ring or a regular polygonal ring.

[0028] In an exemplary embodiment of the present disclosure, the light absorption structure has a minimum width of an orthographic projection on the driving backplate that is a first width, and the first width is greater than or equal to 0.5 μm and less than or equal to 2 μm.

[0029] In an exemplary embodiment of the present disclosure, a slope angle formed by the sidewall and the bottom surface of the light absorption structure is greater than or equal to 20° and less than or equal to 90°.

[0030] In an exemplary embodiment of the present disclosure, the slope angle formed by the side wall and the bottom surface of the light absorption structure is greater than 90° and less than or equal to 160°.

[0031] In an exemplary embodiment of the present disclosure, the sub-pixel includes at least a first light-emitting unit and a second light-emitting unit stacked on one side of the driving backplane, and the first light-emitting unit is connected in series through a charge generation layer; the sub-pixel has a light-emitting phase and a non-light-emitting phase, and the photosensor located in the photosensitive area has a sensing phase and a non-sensing phase, wherein the sensing phase of the photosensor does not overlap with the light-emitting phase of the sub-pixel.

[0032] According to the second aspect of the present disclosure, a method for preparing a display panel is also provided, which is used to prepare the display panel described in any embodiment of the present disclosure, and the method includes: providing a driving backplane; forming a plurality of light absorption structures in at least a partial area on one side of the driving backplane, wherein the minimum light absorption wavelength of the light absorption structure is less than or equal to the minimum light emission wavelength of the sub-pixel corresponding thereto, and the maximum light absorption wavelength of the light absorption structure is greater than or equal to the maximum light emission wavelength of the sub-pixel corresponding thereto; forming a pixel defining layer on one side of the driving backplane; forming pixel openings in the pixel defining layer using a composition process, wherein the light absorption structures are circumferentially arranged around the corresponding pixel openings; and forming a light-emitting functional layer in the pixel openings using a vapor deposition process.

[0033] According to a third aspect of the present disclosure, a display device is further provided, comprising the display panel described in any embodiment of the present disclosure.

[0034] The display panel provided by the present disclosure has a light-absorbing structure disposed on the pixel-defining layer. The light-absorbing structure has a minimum absorption wavelength less than or equal to the minimum emission wavelength of the corresponding sub-pixel, and a maximum absorption wavelength greater than or equal to the maximum emission wavelength of the corresponding sub-pixel. Thus, the light-absorbing structure absorbs light emitted by the corresponding sub-pixel. The light-absorbing structure is disposed circumferentially around the pixel opening, allowing it to absorb lateral light leakage generated by the corresponding sub-pixel and prevent it from propagating to the photosensor in the display panel that detects ambient light. This reduces interference from non-ambient light on the photosensor and improves the photosensor's accuracy in sensing ambient light.

[0035] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are incorporated into and constitute a part of this specification, illustrate embodiments consistent with the present disclosure, and together with the description, serve to explain the principles of the present disclosure. It is apparent that the drawings described below are merely some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0037] FIG1 is a schematic structural diagram of a display panel according to an embodiment of the present disclosure;

[0038] FIG2 is a partial enlarged view of the photosensitive area in FIG1 ;

[0039] FIG3 is a cross-sectional view taken along the dotted line AA in FIG2 ;

[0040] FIG4 is a schematic diagram of a sub-pixel's lateral light leakage being sensed by a photosensor in the related art;

[0041] FIG5 is a schematic diagram of a stack of sub-pixels according to an embodiment of the present disclosure;

[0042] FIG6 is a circuit diagram of a pixel driving circuit according to an embodiment of the present disclosure;

[0043] FIG7 is a timing diagram of each node in a driving method of the pixel driving circuit in FIG6 ;

[0044] FIG8 is a graph showing a brightness decay curve of a sub-pixel in an EM-off phase according to an embodiment of the present disclosure;

[0045] 9-20 are schematic diagrams showing the distribution of light-absorbing structures in a photosensitive area according to an embodiment of the present disclosure;

[0046] FIG21 is an absorption spectrum curve of a compound according to one embodiment of the present disclosure;

[0047] FIG22 is a cross-sectional view of a light absorption structure and a sub-pixel according to one embodiment of the present disclosure;

[0048] FIG23 is a cross-sectional view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure;

[0049] FIG24 is a cross-sectional view of a light absorption structure and a sub-pixel according to yet another embodiment of the present disclosure;

[0050] FIG25 is a top view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure;

[0051] FIG26 is a cross-sectional view taken along the dotted line AA in FIG25 ;

[0052] Figures 27 to 29 are partial enlarged views of a light-absorbing structure in Figure 25;

[0053] FIG30 is a cross-sectional view of a light absorption structure and a sub-pixel according to one embodiment of the present disclosure;

[0054] FIG31 is a partial enlarged view of the light absorption structure in FIG30;

[0055] FIG32 is a cross-sectional view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure;

[0056] FIG33 is a partial enlarged view of the light absorption structure in FIG32;

[0057] FIG34 is a cross-sectional view of a light absorption structure and a sub-pixel according to yet another embodiment of the present disclosure;

[0058] FIG35 is a partial enlarged view of the light absorption structure in FIG34;

[0059] 36 to 39 are flow charts of a method for manufacturing a display panel according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0060] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0061] In related technologies, terminal devices usually install ambient light sensing photosensors on the back of the AMOLED panel to identify the brightness of the user's usage scene, so as to dynamically adjust the display brightness of the terminal device, protect the user's eyesight and reduce its own power consumption.

[0062] The light released by the OLED during the discharge process after power is cut off is refracted and reflected by the anode, cathode, and organic and inorganic film layers, passes through the blank area of ​​the driver backplane wiring, and is received by the ambient light sensing photosensor under the backplane, thereby affecting the sensitivity of the ambient light sensing photosensor.

[0063] Figure 1 is a structural schematic diagram of a display panel according to an embodiment of the present disclosure, Figure 2 is a local enlarged view of the photosensitive area in Figure 1, and Figure 3 is a cross-sectional view along the dotted line AA in Figure 2. As shown in Figures 2 and 3, the display panel may include a driving backplane 110, a pixel defining layer PDL and a plurality of light absorption structures 120, wherein a plurality of sub-pixels emitting light of different colors are formed on one side of the driving backplane 110, the pixel defining layer PDL is located on one side of the driving backplane 110, the pixel defining layer PDL has a pixel opening, and a light-emitting functional layer of the sub-pixel is formed in the pixel opening; the light absorption structure 120 is arranged corresponding to at least part of the sub-pixels, the light absorption structure 120 is located in the pixel defining layer PDL and is circumferentially arranged around the corresponding pixel opening, the minimum light absorption wavelength of the light absorption structure 120 is less than or equal to the minimum light emission wavelength of the sub-pixel corresponding thereto, and the maximum light absorption wavelength of the light absorption structure 120 is greater than or equal to the maximum light emission wavelength of the sub-pixel corresponding thereto.

[0064] The display panel provided herein includes a light absorption structure 120 disposed on the pixel definition layer (PDL). The minimum absorption wavelength of the light absorption structure 120 is less than or equal to the minimum emission wavelength of the corresponding sub-pixel, and the maximum absorption wavelength of the light absorption structure 120 is greater than or equal to the maximum emission wavelength of the corresponding sub-pixel. Thus, the light absorption structure 120 absorbs light emitted by the corresponding sub-pixel. The light absorption structure 120 is disposed circumferentially around the pixel opening, absorbing lateral light leakage generated by the corresponding sub-pixel and preventing it from propagating to the photosensor 101 in the display panel that detects ambient light. This reduces interference from non-ambient light on the photosensor 101 and improves the photosensor's 101 sensing accuracy for ambient light.

[0065] The light absorption structure 120 of the present disclosure is arranged in correspondence with at least some of the sub-pixels, which can be understood as at least some of the sub-pixels in the display panel are provided with a light absorption structure 120, for example, the light absorption structure 120 is arranged in a one-to-one correspondence with some of the sub-pixels. For example, as shown in FIG1 , the display panel may have a photosensitive area 200, and the photosensitive area 200 may be located in the display area. A photoelectric sensor 101 for identifying the brightness of the environment may be provided in the photosensitive area 200, and the display brightness of the display device may be automatically adjusted based on the sensing signal of the photoelectric sensor 101. Therefore, the multiple light absorption structures 120 of the present disclosure are arranged in correspondence with at least some of the sub-pixels, and specifically, the multiple light absorption structures 120 may be arranged in correspondence with at least some of the sub-pixels of the photosensitive area 200. As shown in FIG1 , the photosensitive area 200 of the present disclosure is located in the display area. In addition to being provided with the photoelectric sensor 101 and the light absorption structure 120, the photosensitive area 200 may have all the features of other areas of the display area, which will not be described in detail here.

[0066] As shown in FIG2 , the light absorption structure 120 is disposed circumferentially around the corresponding pixel opening. That is, the light absorption structure 120 encloses a region circumferentially of the pixel opening, and the corresponding pixel opening is located within this region. For example, the orthographic projection of the light absorption structure 120 on the driver backplate 110 is a ring, and the orthographic projection of the pixel opening on the driver backplate 110 is located within this orthographic projection.

[0067] As shown in Figure 3, the light absorption structure 120 is arranged in the circumference of the corresponding pixel opening. In this way, the lateral light leakage generated by the sub-pixel in the pixel opening (including the light directly generated by the sub-pixel and the light reflected by other film layers) will be transmitted to the light absorption structure 120, that is, the light absorption structure 120 is equivalent to being located on the propagation path of the lateral light leakage of the sub-pixel. In this way, the lateral light leakage generated by the sub-pixel will be absorbed by the light absorption structure 120 located on the light transmission path, thereby preventing the lateral light leakage generated by the sub-pixel from being transmitted to the photosensor 101, so that the photosensor 101 only senses ambient light during the sensing stage, thereby eliminating the influence of the lateral light leakage of the sub-pixel on the ambient light detection result, and improving the sensing accuracy of the ambient light. For comparison, FIG4 is a schematic diagram of the lateral light leakage of a sub-pixel being sensed by a photosensor in the related art. As shown in FIG4 , light a and light b are reflected by the second electrode layer (e.g., a cathode layer) and then transmitted through the underlying organic layer to the ambient light sensor below the driver backplane. Light c is refracted by the pixel defining layer and the organic layer and then directly transmitted to the photosensor 101 below, thus causing the detection result of the photosensor 101 to be inaccurate. Compared with FIG3 , it can be seen that after the light absorption structure is provided, light a, light b, and light c from the lateral light leakage of the sub-pixel will all be absorbed by the circumferential light absorption structure 120, so that the detection result of the photosensor 101 is no longer affected by the lateral light leakage of the sub-pixel. Therefore, the present disclosure can improve the sensing accuracy of ambient light by providing the light absorption structure 120.

[0068] The light absorption structure 120 of the present disclosure includes a light absorption material to absorb light of a specific wavelength through the light absorption material. The minimum absorption wavelength and the maximum absorption wavelength are the limit absorption wavelengths of the light absorption structure 120. The minimum absorption wavelength is the minimum wavelength of light that the light absorption structure 120 can absorb, that is, light less than the minimum absorption wavelength cannot be absorbed by the light absorption structure 120. The maximum absorption wavelength is the maximum wavelength that the light absorption structure 120 can absorb, that is, light greater than the maximum absorption wavelength cannot be absorbed by the light absorption structure 120. In other words, light with a wavelength between the minimum absorption wavelength and the maximum absorption wavelength will be absorbed by the light absorption structure 120. In the present disclosure, the minimum absorption wavelength of the light absorption structure 120 is greater than or equal to the minimum emission wavelength of the corresponding sub-pixel, and the maximum absorption wavelength of the light absorption structure 120 is greater than or equal to the maximum emission wavelength of the corresponding sub-pixel, that is, the light absorption structure 120 can absorb the full band of light emitted by the corresponding sub-pixel. The display panel block disclosed herein may be an OLED display panel, which may have an organic electroluminescent layer. The minimum luminous wavelength and the maximum luminous wavelength of the sub-pixel may be obtained by measuring the luminous intensity of light of different wavelengths emitted by the organic electroluminescent layer material forming the sub-pixel. The minimum luminous wavelength is the minimum wavelength in the wavelength band of the light emitted by the organic electroluminescent layer material, and the maximum luminous wavelength is the maximum wavelength in the wavelength band of the light emitted by the organic electroluminescent layer material.

[0069] The display panel disclosed herein may include a pixel defining layer PDL, a first electrode layer, a light-emitting functional layer, and a second electrode layer in the display area. As shown in FIG3 , the pixel defining layer PDL and the first electrode layer are provided on the same surface of the driving backplane 110, and the pixel defining layer PDL exposes each first electrode ANO. Specifically, the pixel defining layer PDL may be provided with a plurality of pixel openings exposing each first electrode ANO. The orthographic projection of any pixel opening on the base substrate may be located within the exposed first electrode ANO, that is, the pixel opening is not larger than the exposed first electrode ANO. For example, the boundary of the pixel opening is located on the inner side of the boundary of the exposed first electrode ANO, that is, the area of ​​the pixel opening is smaller than the area of ​​the exposed first electrode ANO. The shape of the pixel opening may be a polygon such as a rectangle, a pentagon, or a hexagon, but it is not necessarily a regular polygon. The shape of the pixel opening may also be other shapes such as an ellipse, which is not specifically limited here. The first electrode layer may be an anode layer, and the second electrode layer may be a cathode layer. The present disclosure only uses the example of the first electrode layer being the anode layer and the second electrode layer being the cathode layer for illustrative description. Of course, in other embodiments, the first electrode layer may also be the cathode layer, and the second electrode layer may also be the anode layer.

[0070] As shown in Figure 3, the light-emitting functional layer covers the pixel definition layer (PDL) and the first electrode (ANO). The area where the light-emitting functional layer and the first electrode (ANO) overlap is used to form a sub-pixel. The light-emitting functional layer is located within the pixel opening, and the light absorption structure is arranged circumferentially around the pixel opening. This is equivalent to the light absorption structure being arranged circumferentially around the sub-pixel.

[0071] The sub-pixels disclosed herein may be stacked OLED devices (Tandem OLEDs), i.e., comprising multiple light-emitting devices OLED connected in series. Compared to single-layer OLED devices (Single OLEDs), Tandem OLED devices have both high efficiency and long life. FIG5 is a schematic diagram of a stacked sub-pixel according to an embodiment of the present disclosure. As shown in FIG5 , each sub-pixel includes a first electrode ANO, a second electrode CAT, and multiple sub-light-emitting layers between the first electrode ANO and the second electrode CAT (the figure only uses the example of a sub-pixel including two sub-light-emitting layers, the first sub-light-emitting layer 10 and the second sub-light-emitting layer 20, for illustrative purposes). The light-emitting devices of the same sub-pixel may share the same first electrode ANO and the same second electrode CAT. In other words, the same sub-pixel may have only one first electrode ANO and one second electrode CAT.

[0072] For example, as shown in FIG5 , the light-emitting functional layer may include multiple sub-light-emitting layers connected in series, facing away from the driving backplane 110. At least one sub-light-emitting layer is connected in series with an adjacent sub-light-emitting layer via a charge generation layer CGL. When an electrical signal is applied to the first electrode ANO and the second electrode CAT, each sub-light-emitting layer can emit light, and different sub-light-emitting layers can be used to emit light of different colors.

[0073] Each sub-light-emitting layer may include a hole injection layer (HIL), a hole transport layer (HTL), an organic electroluminescent layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL), distributed along the thickness direction away from the driving backplane 110. The specific light-emitting principle will not be detailed here. The number of hole injection layers (HIL), hole transport layers (HTL), electron transport layers (ETL), and electron injection layers (EIL) is not specifically limited, and adjacent sub-light-emitting layers may share one or more of the hole injection layer (HIL), hole transport layer (HTL), electron transport layer (ETL), and electron injection layer (EIL). Furthermore, a charge generation layer (CGL) may be provided between at least two adjacent sub-light-emitting layers, thereby connecting the two sub-light-emitting layers in series to form a tandem OLED device.

[0074] In addition, the display panel may further include a color filter layer (not shown). The color filter layer may be disposed on the side of the second electrode CAT facing away from the driver backplane 110 and include multiple filter sections. Each first electrode ANO is disposed opposite each filter section in a direction perpendicular to the driver backplane 110, i.e., the orthographic projection of a filter section on the driver backplane 110 at least partially overlaps with a first electrode ANO. Each filter section includes at least three color filters. For example, it may include a filter section that transmits red light, a filter section that transmits green light, and a filter section that transmits blue light. After the light emitted by each light-emitting unit passes through the filter section, monochromatic light of different colors can be obtained, thereby achieving color display. A filter section and its corresponding light-emitting unit may constitute a sub-pixel. The color emitted by any sub-pixel is the color of the light transmitted by its filter section. Multiple sub-pixels may constitute a pixel, and each sub-pixel in the same pixel may emit different colors. The color filter layer may further include a light-shielding section that separates the filter sections. The light-shielding section is opaque and blocks the area between the two light-emitting units.

[0075] The above-mentioned light-emitting functional layer structure is only an example and does not constitute a limitation on its film layer. It can include only two sub-light-emitting layers, or more, or only one sub-light-emitting layer, as long as it can cooperate with the color filter layer to achieve color display.

[0076] The driving backplane may include multiple transistors forming a pixel driving circuit. The pixel driving circuit may be, for example, a 7T1C, an 8T1C, etc. Taking the 7T1C as an example, FIG6 is a circuit diagram of a pixel driving circuit according to an embodiment of the present disclosure. As shown in FIG6 , the pixel driving circuit may include: a first transistor T1, a second transistor T2, a driving transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, and a capacitor C. The first transistor T1 has a first electrode connected to node N, a second electrode connected to the first initial signal terminal Vinit1, and a gate connected to the reset signal terminal Re1. The second transistor T2 has a first electrode connected to the first electrode of the driving transistor T3, a second electrode connected to node N, and a gate connected to the gate drive signal terminal Gate. The gate of the driving transistor T3 is connected to node N. The fourth transistor T4 has a first electrode connected to the data signal terminal Da, a second electrode connected to the second electrode of the driving transistor T3, and a gate connected to the gate drive signal terminal Gate. The fifth transistor T5 has a first electrode connected to the second electrode of the driving transistor T3, a second electrode connected to the first power supply terminal VDD, and a gate connected to the enable signal terminal EM. The sixth transistor T6 has a first electrode connected to the first electrode of the driving transistor T3, and a gate connected to the enable signal terminal EM. The seventh transistor T7 has a first electrode connected to the second electrode of the sixth transistor T6, a second electrode connected to the second initial signal terminal Vinit2, and a gate connected to the reset signal terminal Re2. A capacitor C is connected between the gate of the driving transistor T3 and the first power supply terminal VDD. The pixel driving circuit can be connected to a light-emitting unit OLED (for example, the light-emitting unit OLED can be the aforementioned Tandem OLED) to drive the light-emitting unit OLED to emit light. The light-emitting unit OLED can be connected between the second electrode of the sixth transistor T6 and the second power supply terminal VSS. The transistors T1 to T7 can all be P-type transistors or N-type transistors, or some can be P-type transistors and some can be N-type transistors. For example, the first transistor T1 to the seventh transistor T7 can all be P-type transistors or all can be N-type transistors, or the first transistor T1 and the second transistor T2 can be P-type transistors, and the third transistor T3 to the seventh transistor T7 can be N-type transistors, etc.

[0077] It should be noted that the transistors used in each embodiment of the present disclosure can be thin film transistors, field effect transistors, or other devices with the same characteristics. In this specification, the first electrode can be a drain electrode and the second electrode can be a source electrode, or the first electrode can be a source electrode and the second electrode can be a drain electrode.

[0078] FIG7 is a timing diagram of each node in a driving method for the pixel driving circuit in FIG6 . Gate represents the timing of the gate driving signal terminal Gate, Re1 represents the timing of the reset signal terminal Re1, Re2 represents the timing of the reset signal terminal Re2, EM represents the timing of the enable signal terminal EM, and Da represents the timing of the data signal terminal Da. The driving method for the pixel driving circuit may include a reset phase t1, a compensation phase t2, and a light-emitting phase t3. During the reset phase t1, the reset signal terminal Re1 outputs a low-level signal, the first transistor T1 turns on, and the first initial signal terminal Vinit1 inputs an initial signal to the node N. During the compensation phase t2, the reset signal terminal Re2 and the gate driving signal terminal Gate output low-level signals, the fourth transistor T4, the second transistor T2, and the seventh transistor T7 turn on, and the data signal terminal Da outputs a driving signal to write a voltage Vdata+Vth to the node N, where Vdata is the voltage of the driving signal and Vth is the threshold voltage of the driving transistor T3. The second initial signal terminal Vinit2 inputs an initial signal to the second electrode of the sixth transistor T6. Light-emitting stage t3: The enable signal terminal EM outputs a low-level signal, the sixth transistor T6 and the fifth transistor T5 are turned on, and the light-emitting unit OLED emits light under the action of the voltage Vdata + Vth stored in the capacitor C. According to the output current formula of the driving transistor I = (μWCox / 2L)(Vgs-Vth) 2 , where μ is the carrier mobility; Cox is the gate capacitance per unit area, W is the width of the driver transistor channel, L is the length of the driver transistor channel, Vgs is the gate-source voltage difference of the driver transistor, and Vth is the threshold voltage of the driver transistor. The output current of the driver transistor in the pixel driving circuit of the present disclosure is I = (μWCox / 2L)(Vdata+Vth-Vdd-Vth) 2 The pixel driving circuit can avoid the influence of the threshold voltage of the driving transistor on its output current.

[0079] The dimming mode of AMOLED display panels is primarily PWM (Pulse Width Modulation) dimming, and the display brightness of the display device can be adjusted by controlling the duty cycle of the emission signal. Figure 8 shows a graph of the brightness decay curve of a subpixel during the EM signal off phase according to one embodiment of the present disclosure. As shown in Figure 8, the photosensor 101 of the present disclosure is turned on to sense ambient light when the enable signal terminal EM is off. The OLED device can be viewed as an equivalent circuit consisting of a resistor and a capacitor in parallel. The device's inherent capacitance affects its response speed to voltage. That is, the larger the device capacitance, the longer it takes for the OLED device to reach the turn-on potential at the same current. Similarly, under a constant discharge current, the discharge time also increases with the increase in device capacitance. The inherent capacitance of the tandem OLED device is larger than that of the single OLED device. Due to the influence of the tandem OLED device's larger capacitance, as shown in stage t0 in Figure 8, after receiving the EM signal off, the tandem OLED device's discharge process is slow, and the OLED brightness cannot be quickly reduced to the target value. As a result, the photosensor 101 senses the lateral light leakage of the sub-pixel when the enable signal terminal EM outputs the off signal, thereby reducing the sensing accuracy of the ambient light.

[0080] The structure and principle of the display panel disclosed herein are described in detail below.

[0081] In an exemplary embodiment, the multiple sub-pixels formed on the driving backplane 110 may generally include R sub-pixels, G sub-pixels and B sub-pixels. The light absorption structure 120 disclosed in the present invention may be arranged in a one-to-one correspondence with only one of the three sub-pixels in the above-mentioned photosensitive area 200. For example, the light absorption structure 120 may include a first light absorption structure 121, a second light absorption structure 122 and a third light absorption structure 123, wherein the first light absorption structure 121 is a light absorption structure arranged circumferentially around the G sub-pixel, the second light absorption structure 122 is a light absorption structure arranged circumferentially around the R sub-pixel, and the third light absorption structure 123 is a light absorption structure arranged circumferentially around the B sub-pixel.

[0082] For example, as shown in FIG2 , the display panel may include only the first light absorption structure 121, that is, the display panel includes only the light absorption structure arranged around the G sub-pixel, and the first light absorption structure 121 may be arranged in a one-to-one correspondence with the G sub-pixel. Alternatively, as shown in FIG9 and FIG10 , FIG10 is a cross-sectional view taken along dotted line AA in FIG9 , the display panel may include only the third light absorption structure 123, that is, the display panel includes only the light absorption structure arranged around the B sub-pixel, and the third light absorption structure 123 may be arranged in a one-to-one correspondence with the B sub-pixel. Alternatively, as shown in FIG11 and FIG12 , FIG12 is a cross-sectional view taken along dotted line AA in FIG11 , the display panel may include only the second light absorption structure 122, that is, the display panel includes only the light absorption structure arranged around the R sub-pixel, and the second light absorption structure 122 may be arranged in a one-to-one correspondence with the R sub-pixel.

[0083] In other embodiments, the light absorption structure 120 may be provided in a one-to-one correspondence with any two of the three sub-pixels in the photosensitive area 200. For example, as shown in FIG13 and FIG14 , FIG14 is a cross-sectional view taken along dotted line AA in FIG13 , and the display panel may include both a first light absorption structure 121 and a second light absorption structure 122. The first light absorption structure 121 may be provided in a one-to-one correspondence with the G sub-pixel, and the second light absorption structure 122 may be provided in a one-to-one correspondence with the R sub-pixel. Alternatively, as shown in FIG15 and FIG16 , FIG16 is a cross-sectional view taken along dotted line AA in FIG15 , and the display panel may include both a second light absorption structure 122 and a third light absorption structure 123. The second light absorption structure 122 may be provided in a one-to-one correspondence with the R sub-pixel, and the third light absorption structure 123 may be provided in a one-to-one correspondence with the B sub-pixel. Or as shown in Figures 17 and 18, Figure 18 is a cross-sectional view along the dotted line AA in Figure 17, the display panel can also include a first light absorption structure 121 and a third light absorption structure 123 at the same time, and the first light absorption structure 121 can be set in a one-to-one correspondence with the G sub-pixel, and the third light absorption structure 123 can be set in a one-to-one correspondence with the B sub-pixel.

[0084] In other embodiments, as shown in Figures 19 and 20, Figure 20 is a cross-sectional view along the dotted line AA in Figure 19, and the display panel may also simultaneously include a first light absorption structure 121, a second light absorption structure 122 and a third light absorption structure 123, that is, the three sub-pixels R, G, and B in the photosensitive area 200 are all provided with a light absorption structure 120 corresponding to them.

[0085] Typically, green light accounts for the highest proportion of white light and is primarily sensed by the photosensor 101. However, in the device structure, green light decays the slowest, so green light has the greatest impact on the sensing accuracy of the photosensor 101. Therefore, in a preferred embodiment of the present disclosure, when the photosensitive area 200 includes only one light absorption structure, it can be that the light absorption structure 121 is provided only in a one-to-one correspondence around the G sub-pixel as shown in FIG2 to improve the lateral light leakage of green light and enhance the photosensor 101's sensing accuracy for ambient light. Alternatively, when the photosensitive area 200 includes two light absorption structures, it can be that the second light absorption structure 122 is provided in a one-to-one correspondence around the R sub-pixel and the first light absorption structure 121 is provided in a one-to-one correspondence around the G sub-pixel as shown in FIG10, or that the first light absorption structure 121 is provided in a one-to-one correspondence around the G sub-pixel and the third light absorption structure 123 is provided in a one-to-one correspondence around the B sub-pixel as shown in FIG12. Similarly, by improving the light absorption effect for green light, the sensing accuracy for ambient light is improved.

[0086] As shown in Figure 2, in an exemplary embodiment, when the photosensitive area 200 only includes the first light absorption structure 121, the minimum absorption wavelength of the first light absorption structure 121 is less than or equal to the minimum emission wavelength of the G sub-pixel, and the maximum absorption wavelength of the first light absorption structure 121 is greater than or equal to the maximum emission wavelength of the G sub-pixel.

[0087] For example, the material of the first light absorption structure 121 includes a compound represented by the following structural formula (1):

[0088] For example, the compound of the structural formula (1) can be added to a polyimide precursor and then formed into the first light absorption structure 121 through an exposure process. FIG21 shows the absorption spectrum curve of the compound. As shown in FIG21 , the compound has a strong absorption effect in the green light band. The first light absorption structure 121 thus formed can absorb the lateral light leakage of the G sub-pixel, thereby preventing the light from leaking to the photosensor 101.

[0089] In addition, the material of the first light absorption structure 121 can also be a black material. For example, the black material can be black polyimide glue (PI), which can also be prepared through an exposure process to form the first light absorption structure 121. The black PI glue has strong light absorption in the 300-700nm band. Therefore, the first light absorption structure 121 formed can also absorb the lateral light leakage of the G sub-pixel, preventing light leakage to the photosensor 101. Furthermore, the material of the second light absorption structure 122 and the third light absorption structure 123 can also be a black material. The second light absorption structure 122 and the third light absorption structure 123 formed of black material also have a good light absorption effect on the lateral light leakage of the R sub-pixel and the B sub-pixel.

[0090] Figure 22 is a cross-sectional view of a light absorption structure and a sub-pixel according to an embodiment of the present disclosure, showing three sub-pixels of R, G, and B. As shown in Figure 22, the inner wall of the light absorption structure 120 can be in contact with the side wall of the first electrode ANO of the corresponding sub-pixel. Specifically, the inner wall of the light absorption structure 120 refers to the side wall of the light absorption structure 120 facing the sub-pixel surrounded by the light absorption structure 120. The first electrode ANO has a certain thickness in the thickness direction of the driving backplane 110, thereby causing the first electrode ANO to have a side wall facing the light absorption structure 120. The inner wall of the light absorption structure 120 is in contact with the side wall of the first electrode ANO of the corresponding sub-pixel, that is, the light absorption structure 120 is circumferentially arranged to fit the side wall of the first electrode ANO of the corresponding sub-pixel. Therefore, under this structure, there is no gap between the light absorption structure 120 and the first electrode ANO surrounded by it. This structure can prevent some light at a specific angle from entering the photosensor 101 on the non-display side through the gap between the light absorption structure 120 and the first electrode ANO. Therefore, this structure can fully ensure the light absorption effect of the light absorption structure 120 on the lateral light leakage of the sub-pixel.

[0091] For example, due to the mask shadow problem, organic electroluminescent layer material will usually remain on the pixel definition layer PDL. The residual light-emitting layer material will self-luminesce under the lateral leakage of the OLED device. As shown in Figure 4, the light c generated by the residual light-emitting layer material may just pass through the gap between the light absorption structure 120 and the corresponding sub-pixel at a specific angle and be transmitted to the photosensor 101 on the non-display side. In this exemplary embodiment, because the inner wall of the light absorption structure 120 directly contacts the side wall of the first electrode ANO of the sub-pixel surrounded by it, the light absorption structure 120 can absorb light at extreme angles such as light c, so that the light absorption structure 120 has the best light absorption effect.

[0092] FIG23 is a cross-sectional view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure, and FIG24 is a cross-sectional view of a light absorption structure and a sub-pixel according to yet another embodiment of the present disclosure. As shown in FIG23 and FIG24 , in exemplary embodiments, the light absorption structure 120 may partially overlap with the first electrode ANO. For example, as shown in FIG23 , a portion of the light absorption structure 120 is located on the first electrode ANO and a portion is located on the driving backplane; or, as shown in FIG24 , the light absorption structure 120 is entirely located on the first electrode ANO. All of these fall within the scope of protection of the present disclosure.

[0093] Figure 25 is a top view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure, and Figure 26 is a cross-sectional view along the dotted line AA in Figure 25, showing three sub-pixels in a pixel unit, and taking the three sub-pixels as an example for exemplary description. As shown in Figures 25 and 26, in an exemplary embodiment, there may be a gap between the inner wall of the light absorption structure 120 and the side wall of the first electrode ANO of the corresponding sub-pixel, that is, the inner wall of the light absorption structure 120 does not contact the side wall of the first electrode ANO of the sub-pixel surrounded by it. As shown in Figure 25, the orthographic projection of the light absorption structure 120 on the driving backplane 110 is a ring, which surrounds the outer periphery of the orthographic projection of the corresponding sub-pixel on the driving backplane 110. In some embodiments, the orthographic projection of the light absorption structure 120 on the driving backplane 110 may be a circular ring or a regular polygonal ring, and the regular polygonal ring may be, for example, a rectangular ring, a regular pentagonal deformed ring, a regular hexagonal ring, etc. In some other embodiments, the orthographic projection of the light absorption structure 120 on the driving backplate 110 may also be an irregular ring.

[0094] Figure 27 is a partial enlarged view of a light-absorbing structure in Figure 25. As shown in Figure 27, the light-absorbing structure 120 has a relative inner side L1 and an outer side L2 on the positive projection of the driving backplane 110, and a first straight line k passing through any first node on the inner side L1 and extending along the first direction intersects with the outer side L2 at a second node, and the first node and the second node have a third width d3 in the first direction; the light-absorbing structure 120 has a gap between the inner side L1 of the positive projection of the driving backplane 110 and the edge of the positive projection of the first electrode ANO of the corresponding sub-pixel on the driving backplane 110, and the first straight line k intersects with the edge of the positive projection of the first electrode ANO on the driving backplane 110 at a third node, and the first node and the third node have a second width d2 in the first direction, and the second width d2 is less than or equal to the third width d3.

[0095] Among them, there is a third width d3 between the first node and the second node, and a second width d2 between the first node and the third node. The second width d2 reflects the gap width between the inner wall of the light absorption structure 120 and the first electrode ANO of the corresponding sub-pixel, and the third width d3 reflects the wall thickness of the light absorption structure 120. As described above, the orthographic projection of the light absorption structure 120 on the driving backplane 110 can be a circular ring or a polygonal ring. When the orthographic projection of the light absorption structure 120 on the driving backplane 110 is a circular ring, the first straight line k is not tangent to the inner side L1; when the orthographic projection of the light absorption structure 120 on the driving backplane 110 is a polygonal ring, the first straight line k intersects with the inner side L1. In this way, it is ensured that the first straight line k can have an intersection with the inner side L1, the outer side L2 and the orthographic projection edge of the first electrode ANO.

[0096] The second width d2 is less than or equal to the third width d3 , indicating that the thickness of the light absorption structure 120 is greater than the gap width between the light absorption structure 120 and the first electrode ANO of the corresponding sub-pixel.

[0097] Specifically, as shown in FIG28 , when the orthographic projection of the light absorption structure 120 on the driving backplate 110 is a circular ring and the first straight line k passes through the center of the circular ring, or as shown in FIG29 , when the orthographic projection of the light absorption structure 120 on the driving backplate 110 is a polygonal ring and the first straight line k is perpendicular to the inner side L1, the third width d3 has a minimum value, which is recorded as the first width d1. Obviously, the first width d1 is the wall thickness of the light absorption structure 120. In this case, the second width d2 is less than or equal to the first width d1, that is, the wall thickness of the light absorption structure 120 must be greater than or equal to the gap width between the light absorption structure 120 and the first electrode ANO of the corresponding sub-pixel. Because the wall thickness of the light absorption structure 120 is relatively small, when the first width d1 is less than or equal to the second width d2, the gap between the light absorption structure 120 and the corresponding sub-pixel is also relatively small. This can reduce the amount of light transmitted to the photosensor 101 through the gap, which is beneficial for improving the light absorption structure 120's absorption effect on lateral light leakage from the sub-pixel.

[0098] In some embodiments, the ratio of the second width d2 to the first width d1 may be greater than or equal to 0 and less than or equal to 1, for example, 0, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, 1, etc. Specifically, when there is no gap between the inner wall of the light absorption structure 120 and the first electrode ANO of the corresponding sub-pixel, that is, when the inner wall of the light absorption structure 120 directly contacts the edge of the first electrode ANO of the corresponding sub-pixel, the second width d2 is 0, and accordingly, the ratio of the second width d2 to the first width d1 is 0. When the wall thickness of the light absorption structure 120 is relatively small, the wall thickness of the light absorption structure 120 may be the same as the width of the gap between the inner wall of the light absorption structure 120 and the first electrode ANO of the corresponding sub-pixel.

[0099] According to the above-mentioned proportional relationship, the gap width between the inner wall of the light absorption structure 120 and the side wall of the first electrode ANO is set according to the width of the light absorption structure 120, so that the distance between the inner wall of the light absorption structure 120 and the edge of the first electrode ANO of the corresponding sub-pixel is small enough, thereby avoiding the situation where the gap width between the inner wall of the light absorption structure 120 and the first electrode ANO is too large, causing part of the light to be transmitted to the photosensor 101 through the gap, thereby improving the absorption effect of lateral light leakage generated by the sub-pixel.

[0100] For example, in some embodiments, the first width d1 may be greater than or equal to 0.5 μm and less than or equal to 2 μm, for example, it may be 0.5 μm, 0.6 μm, 0.8 μm, 1 μm, 1.2 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2.0 μm, etc. Correspondingly, the second width d2 may be greater than or equal to 0 and less than or equal to 0.5 μm, for example, it may be 0, 0.2 μm, 0.4 μm, 0.5 μm, etc.

[0101] Furthermore, it should be understood that the wall thickness of the light-absorbing structure 120 may be gradually varied in the thickness direction of the driving backplate 110, for example, it may be a structure that is narrow at the top and wide at the bottom, or a structure that is wide at the top and narrow at the bottom. In this case, the wall thickness of the light-absorbing structure 120 refers to the maximum thickness of the light-absorbing structure 120. For example, if the wall thickness of the light-absorbing structure 120 gradually decreases in a direction away from the driving backplate 110, then the first width d1 is the thickness of the bottom surface of the light-absorbing structure 120 in contact with the driving backplate 110; alternatively, if the wall thickness of the light-absorbing structure 120 gradually increases in a direction away from the driving backplate 110, then the first width d1 is the thickness of the top surface of the light-absorbing structure 120 facing away from the driving backplate 110.

[0102] FIG30 is a cross-sectional view of a light absorption structure and a sub-pixel according to an embodiment of the present disclosure, and FIG31 is a partially enlarged view of the light absorption structure in FIG30 . As shown in FIG30 and FIG31 , the light absorption structure 120 may include a first structure layer M1 and a second structure layer M2 parallel to the driving backplane 110. The first structure layer M1 is located at any position on the side of the second structure layer M2 away from the driving backplane 110, and the orthographic projection of the first structure layer M1 on the driving backplane 110 is located within the orthographic projection of the second structure layer M2 on the driving backplane 110. The first structure layer M1 and the second structure layer M2 can be understood as planar structures formed by cutting the light absorption structure 120 with a plane parallel to the driving backplane 110. The first structure layer M1 is located at any position on the side of the second structure layer M2 away from the driving backplane 110, that is, in the structure shown in FIG30 , the first structure layer M1 is located on top of the second structure layer M2. The orthographic projection of the first structural layer M1 on the driving backplane 110 is located within the orthographic projection of the second structural layer M2 on the driving backplane 110, indicating that the light absorption structure 120 is a structure that is narrow at the top and wide at the bottom. In other words, the side wall of the light absorption structure 120 forms a climbing structure from the bottom close to the driving backplane 110 to the top away from the driving backplane 110.

[0103] FIG32 is a cross-sectional view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure, and FIG33 is a partial enlarged view of the light absorption structure in FIG32 . As shown in FIG32 and FIG33 , the light absorption structure 120 includes a first structure layer M1 and a second structure layer M2 parallel to the driving backplane 110. The first structure layer M1 is located at any position on the side of the second structure layer M2 away from the driving backplane 110, and the orthographic projection of the first structure layer M1 on the driving backplane 110 overlaps with the orthographic projection of the second structure on the driving backplane 110. At this time, the dimensions of the light absorption structure 120 at different positions in the thickness direction of the driving backplane 110 are the same, that is, the light absorption structure 120 is a structure of equal width at the top and bottom. Structures of equal width at the top and bottom are easy to implement in the process and can reduce the difficulty of the preparation process.

[0104] Continuing with reference to Figures 30 to 33, the sidewall and bottom surface of the light absorption structure 120 have a slope angle, α, greater than or equal to 20° and less than or equal to 90°, and can be, for example, 20°, 30°, 40°, 45°, 50°, 60°, 70°, 80°, etc. As described above, the light absorption structure 120 has a bottom surface proximal to the driving backplate 110 in the thickness direction of the driving backplate 110 and a top surface distal to the driving backplate 110. In this exemplary embodiment, the slope angle α can be understood as follows: a first tangent plane perpendicular to the driving backplate 110 in the thickness direction of the driving backplate 110 intersects the outer wall of the light absorption structure 120 at the fourth side L4 and intersects the bottom surface of the light absorption structure 120 at the fifth side L5, and a first angle is formed between the fourth side L4 and the fifth side L5. This first angle is the slope angle α of the light absorption structure 120. The first cutting plane is perpendicular to the plane of the driving backplate 110, which is equivalent to cutting the light absorption structure 120 with the first cutting plane to form a fourth side L4 and a fifth side L5 on the side and bottom surfaces of the light absorption structure 120, respectively. Therefore, the first angle between the fourth side L4 and the fifth side L5 is the slope angle α of the light absorption structure 120. When the slope angle α is 90°, the light absorption structure 120 with equal width at the top and bottom is formed as shown in Figure 33. When the slope angle α is less than 90°, the light absorption structure 120 with narrow top and wide bottom is formed as shown in Figure 31.

[0105] It is understandable that, when the height of the light absorption structure 120 is constant, the smaller the slope angle of the light absorption structure 120, the wider the lateral width of the light absorption structure 120, thereby resulting in a larger space between two adjacent first electrodes ANO occupied by the light absorption structure 120, resulting in a reduction in the effective light transmission area of ​​the pixel definition layer PDL in the photosensitive area 200, which is equivalent to reducing the aperture ratio of the photosensitive area 200, resulting in a decrease in the transmittance of the photosensitive area 200. In display products, for example, in some terminal devices, the photosensitive area 200 usually corresponds to the distance sensor area, or in some terminals, the photosensitive area 200 overlaps with the under-screen fingerprint area. When the transmittance of the pixel definition layer PDL in the photosensitive area 200 is reduced, it will affect the normal operation of the distance sensor and the under-screen fingerprint sensor. Therefore, this exemplary embodiment sets the slope angle α of the light absorption structure 120 based on the above-mentioned angle range, which can shrink the lateral width of the light absorption structure 120, thereby reducing the space between adjacent first electrodes ANO occupied by the light absorption structure 120, and reducing the impact on the transmittance of the photosensitive area 200, thereby ensuring that the photosensitive area 200 has better transmittance.

[0106] FIG34 is a cross-sectional view of a light absorption structure and a sub-pixel according to another embodiment of the present disclosure, and FIG35 is a partially enlarged view of the light absorption structure in FIG34 . As shown in FIG34 and FIG35 , the light absorption structure 120 includes a first structure layer M1 and a second structure layer M2 that are parallel to the driving backplane 110. The first structure layer M1 is located at any position on the side of the second structure layer M2 that is away from the driving backplane 110. The orthographic projection of the second structure layer M2 on the driving backplane 110 is located within the orthographic projection of the first structure layer M1 on the driving backplane 110. In other words, the light absorption structure 120 in this exemplary embodiment has a structure that is wide at the top and narrow at the bottom. It can be understood that the lateral light leakage generated by the sub-pixels will be emitted at different angles. When some light is incident on the top of the pixel defining layer PDL at a certain angle, it will pass through the pixel defining layer PDL and be reflected by the second electrode layer above the pixel defining layer PDL. After reflection by the second electrode layer, it may further pass through the pixel defining layer PDL to enter the photosensor 101 on the back of the display panel. For example, the light a and light d in Figure 4 will be reflected back to the pixel defining layer PDL by the second electrode layer after passing through the pixel defining layer PDL, and pass through the pixel defining layer PDL and be transmitted to the photosensor 101 on the non-display side. It can be seen that the light d is closer to the sub-pixel than the light a, that is, the incident angle of the light d is smaller, which may cause this type of light with a smaller incident angle to be reflected by the second electrode layer and transmitted to the photosensor 101, that is, this type of light with a smaller incident angle may escape the light absorption structure 120. In this exemplary embodiment, the light absorption structure 120 is formed into a structure that is wide at the top and narrow at the bottom. In this way, because the top of the light absorption structure 120 is wider, its top can cover those light rays with smaller incident angles to prevent these light rays from escaping. That is, under this structure, the light absorption structure 120 can block the lateral light leakage of sub-pixels within a larger angle range. Therefore, compared with the light absorption structure 120 shown in Figure 30 or Figure 32 above, the light absorption structure 120 in this exemplary embodiment has a better light absorption effect on the lateral light leakage of sub-pixels, and is more conducive to improving the ambient light sensing accuracy of the photosensor 101.

[0107] As shown in FIG34 , in this exemplary embodiment, the slope angle α between the side wall and the bottom surface of the light absorption structure 120 can be greater than 90° and less than or equal to 160°, for example, it can be 100°, 110°, 120°, 130°, 140°, 150°, 160°, etc. The meaning of the slope angle can be found in the introduction of the above embodiments and will not be repeated here. In this exemplary embodiment, by setting the slope angle of the light absorption structure 120 to the above range, on the one hand, similar to the structure shown in FIG30 , the width of the light absorption structure 120 can be shrunk, thereby occupying a smaller pixel definition layer PDL space, thereby reducing the impact on the transmittance of the photosensitive area 200. On the other hand, the increase in the slope angle can expand the width of the top surface of the light absorption structure 120, thereby improving the coverage angle of the lateral light leakage transmitted to the second electrode layer.

[0108] As shown in Figures 30, 32, and 34, in an exemplary embodiment, the light absorption structure 120 may penetrate the pixel definition layer PDL in the thickness direction of the driving backplate 110, that is, the top surface of the light absorption structure 120 and the top surface of the pixel definition layer PDL are located in the same plane parallel to the driving backplate 110. The top surface of a structure described herein can be understood as the structure having a first end surface and a second end surface, the first end surface being in contact with the driving backplate 110, and the second end surface being opposite to the first end surface in the thickness direction of the driving backplate 110, and the second end surface being the top surface of the structure. By setting the light-absorbing structure 120 to pass through the pixel-defining layer PDL, on the one hand, the light-absorbing structure 120 can directly absorb the light emitted by the luminescent material remaining on the pixel-defining layer PDL due to lateral leakage; on the other hand, in the thickness direction of the driving backplane, the light-absorbing structure 120 can block the light that leaks laterally to the second electrode layer within a larger angle range, thereby preventing this part of the light from being reflected by the second electrode layer and then transmitted to the photosensor 101. Therefore, by setting the light-absorbing structure 120 to pass through the pixel-defining layer PDL, it is more conducive to improving the light-absorbing effect of the light-absorbing structure 120 on lateral light leakage.

[0109] Of course, in other embodiments of the present disclosure, the light absorption structure 120 may not penetrate the pixel definition layer PDL in the thickness direction of the driving backplane 110. Specifically, the light absorption structure 120 has a top surface and a bottom surface disposed opposite each other in the thickness direction of the driving backplane, with the bottom surface of the light absorption structure 120 being closer to the driving backplane than the top surface. For example, the bottom surface of the light absorption structure 120 may be located on the driving backplane and / or on the first electrode ANO, and the pixel definition layer PDL covers the top surface of the light absorption structure 120. The top and bottom surfaces of the light absorption structure 120 may have a first thickness between them. As described above, the display panel may further include a second electrode layer (the second electrode layer may be, for example, a cathode layer). The second electrode layer is located on a side of the pixel definition layer facing away from the driving backplane, and at least a portion of the pixel definition layer PDL contacts the second electrode layer on one side and contacts the driving backplane on the other side. The pixel definition layer PDL has a second thickness at the location where it contacts the second electrode layer, and the first thickness is less than the second thickness. That is, the height of the light absorption structure is less than the thickness of the pixel definition layer PDL.

[0110] Taking into account that the light absorption structure 120 has a certain wall thickness, only a very small part of the light can be reflected by the second electrode layer to the photosensor 101. Therefore, by reducing the thickness difference between the first thickness and the second thickness, for example, the ratio of the first thickness to the second thickness is greater than or equal to 0.6, for example, it can be 0.6, 0.7, 0.8, 0.9, etc., when the top of the light absorption structure is covered by the pixel definition layer PDL, the light absorption structure 120 can also have a good light absorption effect.

[0111] The present disclosure further provides a method for manufacturing a display panel, which can be used to manufacture the display panel described in any of the above embodiments of the present disclosure. The method may include the following steps:

[0112] S110: As shown in FIG36 , provide a driving backplane 100. The specific structure of the driving backplane 100 will not be described in detail here.

[0113] S120. As shown in FIG37 , a plurality of light absorption structures 120 are formed in at least a partial area of ​​one side of the driving backplane 100, wherein the minimum light absorption wavelength of the light absorption structure 120 is less than or equal to the minimum light emission wavelength of the corresponding sub-pixel, and the maximum light absorption wavelength of the light absorption structure 120 is greater than or equal to the maximum light emission wavelength of the corresponding sub-pixel.

[0114] As shown in Figure 37, in an exemplary embodiment, before forming the light absorption structure 120, an organic material can be driven to deposit on one side of the backplane 100 to form a planarization layer PLN, and then a metal material is deposited on the planarization layer PLN to form a first electrode layer, and then the first electrode layer is patterned to form a plurality of first electrodes ANO distributed in an array. The first electrode ANO can be an anode.

[0115] After forming the first electrode ANO, a material containing a light-absorbing medium can be deposited on the photosensitive region 200 through a deposition process to form a light-absorbing layer. The light-absorbing layer is then patterned through an exposure mask process to form a light-absorbing structure 120. The light-absorbing structure 120 can be disposed around the first electrode ANO. The specific operating principle and structural features of the light-absorbing structure 120 can be found in the description of the above embodiment and will not be repeated here.

[0116] S130 , as shown in FIG. 38 , forming a pixel definition layer (PDL) on one side of the driving backplane 100 . The pixel definition layer (PDL) may be formed by depositing an organic material through a deposition process.

[0117] S140 , forming pixel openings in the pixel definition layer PDL using a patterning process, wherein the light absorption structure 120 is circumferentially arranged around the corresponding pixel openings.

[0118] S150: As shown in FIG39 , a light-emitting functional layer is formed in the pixel opening by using an evaporation process. The process of forming the light-emitting functional layer will not be described in detail here.

[0119] In an exemplary embodiment, after forming the light-emitting functional layer, an encapsulation layer may be further formed, and the encapsulation layer may include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer. Then, a touch control layer may be formed on the encapsulation layer.

[0120] The present disclosure also provides a display device, which may include the display panel described in any of the above embodiments.

[0121] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A display panel, wherein: include: A driving backplane, wherein a plurality of sub-pixels emitting light of different colors are formed on one side of the driving backplane; A pixel defining layer, located on one side of the driving backplane, the pixel defining layer having a pixel opening, and a light-emitting functional layer of the sub-pixel is formed in the pixel opening; A plurality of light absorption structures are arranged corresponding to at least some of the sub-pixels, the light absorption structures are located in the pixel definition layer and are arranged circumferentially around the corresponding pixel openings, the minimum light absorption wavelength of the light absorption structure is less than or equal to the minimum light emission wavelength of the sub-pixel corresponding thereto, and the maximum light absorption wavelength of the light absorption structure is greater than or equal to the maximum light emission wavelength of the sub-pixel corresponding thereto.

2. The display panel according to claim 1, wherein: The display panel has a photosensitive area, and the photosensitive area has a photoelectric sensor; Wherein, the light absorption structure is arranged corresponding to at least part of the sub-pixels of the photosensitive area.

3. The display panel according to claim 1, wherein: The photosensitive area includes an R sub-pixel, a G sub-pixel and a B sub-pixel, and the light absorption structure includes a first light absorption structure; The first light absorption structure is arranged corresponding to at least part of the G sub-pixels, the minimum light absorption wavelength of the first light absorption structure is less than or equal to the minimum light emission wavelength of the G sub-pixels, and the maximum light absorption wavelength of the first light absorption structure is greater than or equal to the maximum light emission wavelength of the G sub-pixels.

4. The display panel according to claim 3, wherein: The minimum absorption wavelength of the first light absorption structure is also less than or equal to the minimum emission wavelength of the B sub-pixel, and the maximum absorption wavelength of the first light absorption structure is also greater than or equal to the maximum emission wavelength of the B sub-pixel.

5. The display panel according to claim 1, wherein: The photosensitive area includes an R sub-pixel, a G sub-pixel and a B sub-pixel, and the light absorption structure includes two light absorption structures among a first light absorption structure, a second light absorption structure and a third light absorption structure; The first light absorption structure is arranged at least corresponding to a part of the G sub-pixels, the second light absorption structure is arranged at least corresponding to a part of the R sub-pixels, and the third light absorption structure is arranged at least corresponding to a part of the B sub-pixels.

6. The display panel according to claim 1, wherein: The photosensitive area includes an R sub-pixel, a G sub-pixel and a B sub-pixel, and the light absorption structure includes a first light absorption structure, a second light absorption structure and a third light absorption structure; The first light absorption structure is arranged at least corresponding to a part of the G sub-pixels, the second light absorption structure is arranged at least corresponding to a part of the R sub-pixels, and the third light absorption structure is arranged at least corresponding to a part of the B sub-pixels.

7. The display panel according to any one of claims 3 to 6, wherein: The first light absorption structure, the second light absorption structure and the third light absorption structure have the same minimum absorption wavelength and the same maximum absorption wavelength, and the minimum absorption wavelength of any light absorption structure is greater than or equal to the minimum light emission wavelength of the B sub-pixel, and the maximum absorption wavelength is also greater than or equal to the maximum light emission wavelength of the B sub-pixel.

8. The display panel according to claim 1, wherein: The material of the light-absorbing structure includes a compound represented by the following structural formula (1): Alternatively, the material of the light absorption structure is a black material.

9. The display panel according to claim 1, wherein: The display panel further includes: A first electrode layer, comprising a plurality of first electrodes distributed in an array, wherein the pixel defining layer has the pixel opening at the first electrode, and the light-emitting functional layer is formed on a side of the first electrode away from the driving backplane; The orthographic projection of the light absorption structure on the driving backplane at least partially overlaps with the orthographic projection of the first electrode on the driving backplane.

10. The display panel according to claim 1, wherein: The display panel further includes: A first electrode layer, comprising a plurality of first electrodes distributed in an array, wherein the pixel defining layer has the pixel opening at the first electrode, and the light-emitting functional layer is formed on a side of the first electrode away from the driving backplane; The orthographic projection of the light absorption structure on the driving backplane does not overlap with the orthographic projection of the first electrode on the driving backplane.

11. The display panel according to claim 1, wherein: The display panel further includes: A first electrode layer, comprising a plurality of first electrodes distributed in an array, wherein the pixel defining layer has the pixel opening at the first electrode, and the light-emitting functional layer is formed on a side of the first electrode away from the driving backplane; Wherein, the light absorption structure contacts the side wall of the corresponding first electrode.

12. The display panel according to claim 1, wherein: The display panel further includes: A first electrode layer, comprising a plurality of first electrodes distributed in an array, wherein the pixel defining layer has the pixel opening at the first electrode, and the light-emitting functional layer is formed on a side of the first electrode away from the driving backplane; The minimum width of the light absorption structure on the orthographic projection of the driving backplane is the first width, and there is a gap between the light absorption structure and the corresponding first electrode, and the gap width is less than or equal to the first width.

13. The display panel according to claim 12, wherein: A ratio of the gap width to the first width is greater than 0 and less than or equal to 1.

14. The display panel according to claim 1, wherein: The light absorption structure penetrates the pixel defining layer in the thickness direction of the driving backplane.

15. The display panel according to claim 1, wherein: The light absorption structure has a bottom surface and a top surface which are arranged opposite to each other in the thickness direction of the driving backplane, the bottom surface is located on a side of the top surface close to the driving backplane, and the pixel defining layer covers the top surface of the light absorption structure.

16. The display panel according to claim 15, wherein: The display panel further includes: A second electrode layer is located on a side of the pixel definition layer away from the driving backplane, and at least one side of a portion of the pixel definition layer contacts the second electrode layer and the other side contacts the driving backplane; Among them, in the thickness direction of the driving backplane, the light absorption structure has a first thickness between the top and bottom surfaces, the pixel defining layer has a second thickness at a position contacting the second electrode layer, and the ratio of the first thickness to the second thickness is greater than or equal to 0.

6.

17. The display panel according to claim 1, wherein: The light absorption structure comprises a first structure layer and a second structure layer which are parallel to the driving backplane, and the first structure layer is located at any position of the second structure layer on a side away from the driving backplane; The orthographic projection of the first structure layer on the driving backplane is located within the orthographic projection of the second structure layer on the driving backplane, or, The orthographic projection of the first structure layer on the driving backplane overlaps with the orthographic projection of the second structure layer on the driving backplane.

18. The display panel according to claim 1, wherein: The light absorption structure comprises a first structure layer and a second structure layer which are parallel to the driving backplane, and the first structure layer is located at any position of the second structure layer on a side away from the driving backplane; The orthographic projection of the second structural layer on the driving backplane is located within the orthographic projection of the first structural layer on the driving backplane.

19. The display panel according to claim 17 or 18, wherein: The orthographic projection of the light absorbing structure on the driving back plate is a circular ring or a regular polygonal ring.

20. The display panel according to claim 17 or 18, wherein: The light absorption structure has a first width as a minimum width of an orthographic projection on the driving backplane. The first width is greater than or equal to 0.5 μm and less than or equal to 2 μm.

21. The display panel according to claim 17, wherein: The slope angle formed by the side wall and the bottom surface of the light absorption structure is greater than or equal to 20° and less than or equal to 90°.

22. The display panel according to claim 18, wherein: The slope angle formed by the side wall and the bottom surface of the light absorption structure is greater than 90° and less than or equal to 160°.

23. The display panel according to claim 2, wherein: The sub-pixel at least includes a first light-emitting unit and a second light-emitting unit stacked on one side of the driving backplane, and the first light-emitting unit is connected in series via a charge generation layer; The sub-pixel has a light-emitting phase and a non-light-emitting phase, and the photosensor located in the photosensitive area has a sensing phase and a non-sensing phase, wherein the sensing phase of the photosensor does not overlap with the light-emitting phase of the sub-pixel.

24. A method for preparing a display panel, wherein: For preparing the display panel according to any one of claims 1 to 23, the method comprises: Provide drive backplane; A plurality of light absorption structures are formed in at least a portion of a side of the driving backplane, wherein the minimum light absorption wavelength of the light absorption structure is less than or equal to the minimum light emission wavelength of the corresponding sub-pixel, and the maximum light absorption wavelength of the light absorption structure is greater than or equal to the maximum light emission wavelength of the corresponding sub-pixel. Light emission wavelength; forming a pixel defining layer on one side of the driving backplane; Forming a pixel opening in the pixel definition layer by a patterning process, wherein the light absorption structure is circumferentially arranged around the corresponding pixel opening; A light-emitting functional layer is formed in the pixel opening by using an evaporation process.

25. A display device, wherein: A display panel comprising any one of claims 1-24.

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