Display panel, manufacturing method thereof, and display device

Abstract

The present disclosure provides a display panel and a manufacturing method thereof, and a display device, and relates to the technical field of display. The display panel comprises a substrate, a driving layer formed with a first type of pixel circuit and a second type of pixel circuit, a light emitting layer formed with a first type of light emitting device and a second type of light emitting device, and a conductive layer comprising a first conductive sheet, wherein the orthographic projection of a driving transistor of the first type of pixel circuit and the orthographic projection of the first conductive sheet have an overlapping area, and the first conductive sheet is used to load a first voltage signal to adjust the threshold voltage of the driving transistor of the first type of pixel circuit. In the present disclosure, the threshold voltage of the driving transistor of the first type of pixel circuit is adjusted based on the first voltage signal loaded on the first conductive sheet, so that the current of the first type of light emitting device is different from the current of the second type of light emitting device, and the light emitting brightness of the first type of light emitting device is close to the light emitting brightness of the second type of light emitting device, thereby improving the display effect of the display panel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, in particular, to a display panel, a manufacturing method thereof and a display device. BACKGROUND

[0002] OLED (Organic Light-Emitting Diode) display panel is more and more concerned and favored by the display industry due to its self-luminous, high contrast, wide color gamut, wide viewing angle, light and thin structure and compatibility with flexibility. However, some OLED display panels have the phenomenon of bright green display, which greatly reduces the display effect.

[0003] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] The purpose of the present disclosure is to provide a display panel, a manufacturing method thereof and a display device, which can reduce the problem of bright green display of the display panel.

[0005] According to one aspect of the present disclosure, a display panel is provided, comprising:

[0006] a substrate;

[0007] a driving layer located on one side of the substrate and formed with a first type of pixel circuit and a second type of pixel circuit, the first type of pixel circuit and the second type of pixel circuit each comprising a driving transistor;

[0008] a light-emitting layer located on the side of the driving layer away from the substrate and formed with a first type of light-emitting device and a second type of light-emitting device, one first type of light-emitting device connected to one first type of pixel circuit, and one second type of light-emitting device connected to one second type of pixel circuit, the first type of light-emitting device and the second type of light-emitting device having different light-emitting efficiencies;

[0009] a conductive layer located between the substrate and the driving layer and comprising a first conductive sheet, the driving transistor of the first type of pixel circuit having an overlapping area with the first conductive sheet in orthographic projection, and the second type of pixel circuit having no overlapping area with the first conductive sheet in orthographic projection, the first conductive sheet being used for loading a first voltage signal;

[0010] The first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit when the light emitting efficiency of the first type of light emitting device is higher than the light emitting efficiency of the second type of light emitting device, or to be greater than the threshold voltage of the driving transistor of the second type of pixel circuit when the light emitting efficiency of the first type of light emitting device is lower than the light emitting efficiency of the second type of light emitting device.

[0011] According to any one of the display panels of the present disclosure, the first type of light emitting device is a green light emitting device, and the first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit.

[0012] According to any one of the display panels of the present disclosure, the second type of pixel circuit includes a first type of sub-pixel circuit and a second type of sub-pixel circuit, and the second type of light emitting device includes a first type of sub-light emitting device and a second type of sub-light emitting device.

[0013] The first type of sub-light emitting device is a red light emitting device, and the second type of sub-light emitting device is a blue light emitting device. One first type of sub-light emitting device is connected to one first type of sub-pixel circuit, and one second type of sub-light emitting device is connected to one second type of sub-pixel circuit.

[0014] The conductive layer includes a second conductive sheet and a third conductive sheet. The driving transistor of the first type of sub-pixel circuit has an overlapping area with the second conductive sheet in a projection. The second conductive sheet is used to load a second voltage signal to increase the threshold voltage of the driving transistor of the first type of sub-pixel circuit.

[0015] The driving transistor of the second type of sub-pixel circuit has an overlapping area with the third conductive sheet in a projection. The third conductive sheet is used to load a third voltage signal to increase the threshold voltage of the driving transistor of the second type of sub-pixel circuit.

[0016] According to any one of the display panels of the present disclosure, the second conductive sheet and the third conductive sheet are in the same layer and have an integrated structure. The second voltage signal and the third voltage signal are the same voltage signal.

[0017] According to any one of the display panels of the present disclosure, the first conductive sheet and the second conductive sheet are arranged in the same layer.

[0018] According to any one of the display panels of the present disclosure, the driving layer is formed with a power signal line and an initial voltage signal line.

[0019] The power signal line is connected with the first conductive sheet, and the initial voltage signal line is connected with the second conductive sheet and the third conductive sheet.

[0020] According to any one of the display panels of the present disclosure, the driving layer comprises:

[0021] The active layer is located on the side of the conductive layer away from the substrate and comprises a first active part, and the first active part comprises a first channel region and first and second connecting parts located on both sides of the first channel region;

[0022] The gate metal layer is located on the side of the active layer away from the substrate and comprises a first conductive part, and the first conductive part and the first channel region have an overlapping region in the direction perpendicular to the substrate;

[0023] The source-drain metal layer is located on the side of the gate metal layer away from the substrate and comprises a first connecting line, a first end of the first connecting line is electrically connected with the first connecting part, and a second end of the first connecting line is electrically connected with the light-emitting device;

[0024] The first and second connecting parts correspond to form a first electrode and a second electrode of the driving transistor, the region of the first conductive part overlapping with the first channel region forms a control electrode of the driving transistor, and the orthographic projection of the first active part included in the first type of pixel circuit is located within the orthographic projection of the first conductive sheet.

[0025] According to any one of the display panels of the present disclosure, the second type of pixel circuit comprises a first type of sub-pixel circuit and a second type of sub-pixel circuit, and the conductive layer comprises a second conductive sheet and a third conductive sheet;

[0026] The orthographic projection of the first active part of the first type of sub-pixel circuit is located within the orthographic projection of the second conductive sheet, and the orthographic projection of the first active part of the second type of sub-pixel circuit is located within the orthographic projection of the third conductive sheet.

[0027] According to one aspect of the present disclosure, a manufacturing method of a display panel is provided, and the method comprises:

[0028] A substrate is provided;

[0029] A conductive layer is manufactured, and the conductive layer comprises a first conductive sheet, and the first conductive sheet is used to load a first voltage signal;

[0030] A driving layer is manufactured on the side of the conductive layer away from the substrate, and the driving layer comprises a first type of pixel circuit and a second type of pixel circuit, the orthographic projection of a driving transistor of the first type of pixel circuit has an overlapping region with the orthographic projection of the first conductive sheet, and the orthographic projection of a driving transistor of the second type of pixel circuit does not have an overlapping region with the orthographic projection of the first conductive sheet.

[0031] A light emitting layer is formed on the side of the driving layer away from the substrate, the light emitting layer comprising a first type of light emitting device and a second type of light emitting device, one of the first type of light emitting device being connected to one of the first type of pixel circuit, one of the second type of light emitting device being connected to one of the second type of pixel circuit, the light emitting efficiency of the first type of light emitting device being different from the light emitting efficiency of the second type of light emitting device;

[0032] The first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit when the light emitting efficiency of the first type of light emitting device is higher than the light emitting efficiency of the second type of light emitting device, or to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be greater than the threshold voltage of the driving transistor of the second type of pixel circuit when the light emitting efficiency of the first type of light emitting device is lower than the light emitting efficiency of the second type of light emitting device.

[0033] According to one aspect of the present disclosure, a display device is provided, comprising the display panel of the above aspect.

[0034] The embodiments of the present disclosure at least have the following technical effects:

[0035] In the embodiments of the present disclosure, the threshold voltage of the driving transistor of the first type of pixel circuit is adjusted by the first conductive sheet and the additional electric field formed based on the first voltage signal loaded on the first conductive sheet, so that the current of the first type of light emitting device is different from the current of the second type of light emitting device after the reliability test of the display panel. In combination with the fact that the light emitting efficiency of the first type of light emitting device is different from the light emitting efficiency of the second type of light emitting device, the light emitting brightness of the first type of light emitting device is closer to the light emitting brightness of the second type of light emitting device, so as to weaken the phenomenon of bright green in use of the display panel, and further to ensure the display effect of the display panel.

[0036] It should be understood that the general description above and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0037] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and together with the specification, serve to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor based on these drawings.

[0038] Figure 1 A cross-sectional structure schematic diagram of a display panel provided by the embodiments of the present disclosure.

[0039] Figure 2 A schematic diagram of a pixel circuit provided for an embodiment of the present disclosure.

[0040] Figure 3 A structural schematic diagram of a first conductive sheet provided for an embodiment of the present disclosure.

[0041] Figure 4 A cross-sectional structural schematic diagram of another display panel provided for an embodiment of the present disclosure.

[0042] Figure 5 A structural schematic diagram of a second conductive sheet, a third conductive sheet provided for an embodiment of the present disclosure.

[0043] Figure 6 A threshold voltage curve of a driving transistor of a first type of pixel circuit, a second type of pixel circuit after positive bias amplitude adjustment provided for an embodiment of the present disclosure.

[0044] Figure 7 A flowchart of a manufacturing method of a display panel provided for an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the specification. Moreover, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an overly literal sense unless expressly so defined herein.

[0046] Although relative terms such as "upper", "lower", etc. are used herein to describe one component's relationship to another component as illustrated in the figures, such terminology is used for convenience only and does not imply that the device as illustrated is "upper" or "lower". Terms such as "on", "under", "right", "left", and the like describe relative positions according to the orientation of the device as shown in the figures. It will be understood that if the device is turned over, the relative positions will be reversed. When a structure is "on" another structure, it can mean that the structure is formed directly on the other structure, or that the structure is "directly" on the other structure, or that the structure is "indirectly" on the other structure via another structure.

[0047] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0048] Figure 1 A schematic diagram illustrating the structure of a display panel provided in an embodiment of this disclosure is shown. Figure 1 As shown, the display panel includes a substrate BP, a driving layer DR, and a light-emitting layer EE. The driving layer DR is located on one side of the substrate BP and has multiple pixel circuits formed thereon. The light-emitting layer EE is located on the side of the driving layer DR opposite to the substrate BP and has multiple light-emitting devices formed thereon. Each pixel circuit is connected to at least one corresponding light-emitting device (e.g., one pixel circuit is connected to one corresponding light-emitting device). In this way, the pixel circuits can drive the corresponding light-emitting devices to emit light, thereby realizing the display of the image.

[0049] The substrate BP can be made of inorganic or organic materials. For example, in some embodiments, the substrate BP can be made of glass materials such as so-lime glass, quartz glass, and sapphire glass, or metal materials such as stainless steel, aluminum, and nickel. In other embodiments, the substrate BP can be made of polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyvinyl phenol (PVP), polyether sulfone (PES), polyimide, polyamide, polyacetal, polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or combinations thereof.

[0050] The substrate BP can be a single-layer material or a composite of multiple materials. For example, in some embodiments, the substrate BP includes a base film layer, a pressure-sensitive adhesive layer, a first polyimide layer, and a second polyimide layer stacked sequentially.

[0051] In some embodiments, the driving layer DR includes an active layer ACT, a gate metal layer G and a source-drain metal layer SD distributed in a direction away from the substrate BP. The active layer ACT can be a polysilicon layer, an oxide thin film layer or other structure layer as long as it can form a channel region of a transistor and two connection parts (with conductive performance) on both sides of the channel region, and the embodiments of the present disclosure do not make any limitation on this.

[0052] The gate metal layer G and the source-drain metal layer SD can be a single-layer structure or a multi-layer structure, for example, the gate metal layer G includes a first gate metal layer and a second gate metal layer, and / or the source-drain metal layer SD includes a first source-drain metal layer and a second source-drain metal layer.

[0053] The driving layer DR further includes a buffer layer Buff located on the side of the active layer ACT close to the substrate BP, a gate insulating layer GI located between the active layer ACT and the gate metal layer G, an interlayer insulating layer ILD located between the gate metal layer G and the source-drain metal layer SD, and a planarization layer PLN located on the side of the source-drain metal layer SD away from the substrate BP.

[0054] For the plurality of pixel circuits of the driving layer DR, the plurality of pixel circuits are distributed in an array, and the pixel circuit can be a 6T1C, 7T1C or other circuit including at least a driving transistor, as long as it can drive at least one light emitting device to emit light, and the embodiments of the present disclosure do not make any special limitation on this. nTmC means that one pixel circuit includes n transistors (denoted by the letter "T") and m capacitors Cst (denoted by the letter "C").

[0055] The transistor can be a thin film transistor, which can be an N-type thin film transistor or a P-type thin film transistor, and the thin film transistor can be selected from a top-gate type thin film transistor, a bottom-gate type thin film transistor or a dual-gate type thin film transistor; and the capacitor can be a dual-plate capacitor or a three-plate capacitor.

[0056] It can be understood that among the plurality of transistors included in one pixel circuit, the types of any two transistors can be the same or different. For example, in some embodiments, part of the transistors in one pixel circuit can be N-type transistors and part of the transistors can be P-type transistors. For another example, in some other embodiments, the material of the active layer ACT of part of the transistors in one pixel circuit can be low-temperature polysilicon semiconductor material, and the material of the active layer ACT of part of the transistors can be metal oxide semiconductor material.

[0057] In some embodiments, taking a 7T1C circuit as an example, as shown in FIG. 1, the driving layer DR includes a first driving transistor T1, a second driving transistor T2, a third driving transistor T3, a fourth driving transistor T4, a fifth driving transistor T5, a sixth driving transistor T6 and a seventh driving transistor T7. Figure 2As shown, the pixel circuit includes a driving transistor DT, a first switch transistor ST1, a second switch transistor ST2, a third switch transistor ST3, a fourth switch transistor ST4, a fifth switch transistor ST5, a sixth switch transistor ST6, and a capacitor Cst.

[0058] The first electrode of the driving transistor DT is electrically connected to the first electrode of the first switch transistor ST1 and the first electrode of the sixth switch transistor ST6, respectively; the second electrode of the driving transistor DT is electrically connected to the second electrode of the third switch transistor ST3 and the first electrode of the fourth switch transistor ST4, respectively; the control electrode of the driving transistor DT is electrically connected to the first electrode of the second switch transistor ST2, the first electrode of the third switch transistor ST3, and the first plate of the capacitor Cst, respectively; the second electrode of the first switch transistor ST1 is used to input a data signal, and the control electrode of the first switch transistor ST1 is used to input a scan signal; the second electrode of the second switch transistor ST2 is used to input an initial voltage signal, and the control electrode of the second switch transistor ST2 is used to input a reset signal; the control electrode of the third switch transistor ST3 is used to input a scan signal; the second electrode of the fourth switch transistor ST4 is electrically connected to the first electrode of the fifth switch transistor ST5 and is used to be electrically connected to the light emitting device, and the control electrode of the fourth switch transistor ST4 is used to input a light emitting control signal; the second electrode of the fifth switch transistor ST5 is used to input an initial voltage signal, and the control electrode of the fifth switch transistor ST5 is used to input a reset signal; the second electrode of the sixth switch transistor ST6 is electrically connected to the second plate of the capacitor Cst and is used to input a power supply signal, and the control electrode of the sixth switch transistor ST6 is used to input a light emitting control signal.

[0059] When the pixel circuit formed by the driving layer DR includes the driving transistor DT, the active layer ACT includes a first active part, the first active part includes a first channel region and a first connection part and a second connection part located on both sides of the first channel region; the gate metal layer G includes a first conductive part, and the first conductive part and the first channel region have an overlapping region in the direction perpendicular to the substrate base plate BP. In this way, the first connection part and the second connection part are correspondingly formed as the first electrode and the second electrode of the driving transistor DT, and the region of the first conductive part overlapping with the first channel region is formed as the control electrode of the driving transistor DT, so as to form the driving transistor DT of the pixel circuit.

[0060] The source-drain metal layer SD includes a first connection line, a first end of the first connection line is electrically connected to the first connection part of the first active part, and a second end of the first connection line is electrically connected to the light emitting device.

[0061] For the plurality of light emitting devices of the light emitting layer EE, the plurality of light emitting devices are distributed in an array, and can be divided into a plurality of light emitting units, each of which includes a plurality of light emitting devices of different light emitting colors, for example, a light emitting unit can include a red light emitting device emitting red light, a green light emitting device emitting green light, and a blue light emitting device emitting blue light.

[0062] In some embodiments, the light emitting device is an organic light emitting diode (OLED), which can include a first electrode, a light emitting functional layer, and a second electrode stacked in sequence in a direction away from the substrate BP.

[0063] The first electrode can be provided on the side of the driving layer DR away from the substrate BP and connected to the corresponding pixel circuit. The light emitting functional layer can include a hole injection layer, a hole transport layer, a composite light emitting layer, an electron transport layer, and an electron injection layer stacked in sequence in a direction away from the substrate BP, and in addition, an electron blocking layer can be provided between the hole transport layer and the composite light emitting layer. The second electrode covers the light emitting functional layer, and the second electrodes of the plurality of light emitting devices can share an electrode layer.

[0064] In the embodiments of the present disclosure, as shown in Figure 1 The display panel includes a pixel definition layer PDL, which can be made of light shielding material, for example, the material of the pixel definition layer PDL can be black photoresist.

[0065] The pixel definition layer PDL is provided with a pixel opening corresponding to each of the plurality of light emitting devices, the first electrode includes an exposed area exposed at the corresponding pixel opening and a covered area covered by the pixel definition layer PDL, and the exposed area of the first electrode forms a light emitting area of the corresponding light emitting device.

[0066] In some embodiments, as shown in Figure 1 The display panel can further include a plurality of support columns DL, which can be provided on the surface of the pixel definition layer away from the substrate BP. In this way, when the light emitting functional layer is formed by the evaporation process, the mask can be supported by the support columns DL.

[0067] At the same time, in order to further block stray light, the support columns DL can also be made of light shielding material, which can be the same material as the pixel definition layer, so that the pixel definition layer PDL and the support columns DL can be formed at the same time by the gray-tone mask process, of course, they can also be formed independently. For example, the material of the support columns DL can be black photoresist.

[0068] Since the support columns DL are formed on the pixel definition layer PDL, the second electrode of the light emitting device can cover the support columns DL and protrude at the support columns DL, but not disconnect.

[0069] In some embodiments, the display panel can further include a thin film encapsulation layer. The thin film encapsulation layer is arranged on a side of the light-emitting layer EE away from the substrate BP to cover the light-emitting devices included in the light-emitting layer EE, thereby protecting the light-emitting devices from water and oxygen in the external environment.

[0070] The thin film encapsulation layer can include inorganic encapsulation layers and organic encapsulation layers arranged in an alternating stack. The inorganic encapsulation layers can effectively block water and oxygen in the external environment, preventing water and oxygen from invading the organic light-emitting functional layer and causing material degradation. The organic encapsulation layers are arranged between adjacent inorganic encapsulation layers to achieve planarization and reduce stress between the inorganic encapsulation layers.

[0071] The display panel has a display area and a peripheral area located at the periphery of the display area. The edges of the inorganic encapsulation layers can be located in the peripheral area, and the edges of the organic encapsulation layers can be located between the edges of the display area and the edges of the inorganic encapsulation layers. Exemplarily, the thin film encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence on a side of the light-emitting layer EE away from the substrate BP.

[0072] In some embodiments, the display panel can further include a touch function layer arranged on a side of the thin film encapsulation layer away from the substrate BP to achieve touch operation of the display panel.

[0073] Before leaving the factory, the display panel will be calibrated for gamma curve to coordinate the natural brightness of the display panel when emitting light and the subjective gray scale perception of the user, and then subjected to reliability tests such as high temperature and high humidity to ensure the quality of the display panel. After the reliability test, the current of each light-emitting device of the light-emitting layer EE of the display panel will increase by the same amplitude, which affects the display effect of the display panel. Specifically, in the case where the light-emitting layer EE includes a plurality of light-emitting devices as described above, the plurality of light-emitting devices include two types of light-emitting devices with different light-emitting efficiencies. In this case, the light-emitting brightness of the light-emitting device with high light-emitting efficiency (green light-emitting device) is better than that of the light-emitting device with low light-emitting efficiency (non-green light-emitting device) under the same current, which further causes the display panel to easily appear bright green when in use, affecting the display effect of the display panel.

[0074] In the embodiments of the present disclosure, in order to ensure that the natural brightness of the display panel when emitting light and the subjective gray scale perception of the user are more coordinated after the reliability test, the display panel can further include a compensation layer arranged on a side of the light-emitting layer EE away from the substrate BP. Figure 1As shown, the plurality of light emitting devices included in the light emitting layer EE are divided into a first type of light emitting device EL1 and a second type of light emitting device EL2, and correspondingly, the plurality of pixel circuits include a first type of pixel circuit PDCA1 and a second type of pixel circuit PDCA2, one first type of light emitting device EL1 is connected with one first type of pixel circuit PDCA1, and one second type of light emitting device EL2 is connected with one second type of pixel circuit PDCA2.

[0075] As shown, Figure 1 As shown, the display panel further includes: a conductive layer BSM located between the substrate BP and the driving layer DR, and including a first conductive sheet BSM1, the first conductive sheet BSM1 is used to load a first voltage signal to adjust the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1, and the first conductive sheet BSM1 is used to load a first voltage signal to adjust the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1. The first conductive sheet BSM1 is used to load a first voltage signal to adjust the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1, and the first conductive sheet BSM1 is used to load a first voltage signal to adjust the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1.

[0076] In this way, by setting the first conductive sheet BSM1, and adjusting the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 based on the additional electric field formed by the first voltage signal loaded on the first conductive sheet BSM1, so that after the reliability test, the current of the first type of light emitting device EL1 is different from the current of the second type of light emitting device EL2. Combined with the fact that the luminous efficiency of the first type of light emitting device EL1 is different from the luminous efficiency of the second type of light emitting device EL2, the luminous brightness of the first type of light emitting device EL1 is closer to the luminous brightness of the second type of light emitting device EL2, so as to weaken the phenomenon of bright green in use of the display panel, and further to ensure the display effect of the display panel.

[0077] Wherein, after loading the first voltage signal on the first conductive sheet BSM1, when the luminous efficiency of the first type of light emitting device EL1 is higher than the luminous efficiency of the second type of light emitting device EL2, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 can be adjusted to be less than the threshold voltage of the driving transistor DT of the second type of pixel circuit PDCA2; when the luminous efficiency of the first type of light emitting device EL1 is lower than the luminous efficiency of the second type of light emitting device EL2, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 can be adjusted to be greater than the threshold voltage of the driving transistor DT of the second type of pixel circuit PDCA2.

[0078] The first type of pixel circuit PDCA1 in the plurality of pixel circuits of the driving layer DR is arranged in the row direction, and the first type of light emitting device EL1 and the second type of light emitting device EL2 are arranged alternately in the row direction. The first type of light emitting device EL1 is a green light emitting device, and the second type of light emitting device EL2 is a non-green light emitting device. The first type of light emitting device EL1 is arranged in the column direction, and the first type of light emitting device EL1 and the second type of light emitting device EL2 are arranged alternately in the column direction. The first type of light emitting device EL1 is a non-green light emitting device, and the second type of light emitting device EL2 is a green light emitting device. Figure 3

[0079] The first type of light emitting device EL1 is a green light emitting device, and the second type of light emitting device EL2 is a non-green light emitting device. The first type of light emitting device EL1 is arranged in the column direction, and the first type of light emitting device EL1 and the second type of light emitting device EL2 are arranged alternately in the column direction. The first type of light emitting device EL1 is a non-green light emitting device, and the second type of light emitting device EL2 is a green light emitting device.

[0080] The first type of light emitting device EL1 is a green light emitting device, and the second type of light emitting device EL2 is a non-green light emitting device. The first type of light emitting device EL1 is arranged in the column direction, and the first type of light emitting device EL1 and the second type of light emitting device EL2 are arranged alternately in the column direction. The first type of light emitting device EL1 is a non-green light emitting device, and the second type of light emitting device EL2 is a green light emitting device.

[0081] The first type of light emitting device EL1 is a green light emitting device, and the second type of light emitting device EL2 is a non-green light emitting device. The first type of light emitting device EL1 is arranged in the column direction, and the first type of light emitting device EL1 and the second type of light emitting device EL2 are arranged alternately in the column direction. The first type of light emitting device EL1 is a non-green light emitting device, and the second type of light emitting device EL2 is a green light emitting device.

[0082] ​Optionally, the positive projection of the driving transistor of the first type of pixel circuit PDCA1 can partially coincide with the positive projection of the first conductive sheet BSM1, or the positive projection of the driving transistor of the first type of pixel circuit PDCA1 can be located within the positive projection of the first conductive sheet BSM1. The present disclosure does not limit this, as long as the first voltage signal loaded on the first conductive sheet BSM1 can adjust the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1.

[0083] For example, the positive projection of the driving transistor of the first type of pixel circuit PDCA1 is located within the positive projection of the first conductive sheet BSM1. At this time, in combination with the case where the first active part of the driving transistor is formed in the active layer ACT, the positive projection of the first active part included in the first type of pixel circuit PDCA1 is located within the positive projection of the first conductive sheet BSM1.

[0084] In the present disclosure, in addition to the conductive sheet arranged directly below the driving transistor of the first type of pixel circuit PDCA1, a conductive sheet can also be arranged directly below the driving transistor of the second type of pixel circuit PDCA2. At this time, the voltage signals loaded on the conductive sheets at the two positions are different, and the voltage signal loaded on one conductive sheet is used to increase the threshold voltage of the driving transistor DT, and the voltage signal loaded on the other conductive sheet is used to decrease the threshold voltage of the driving transistor DT. As long as the threshold voltage of the driving transistor DT of the pixel circuit corresponding to the light-emitting device with high luminous efficiency is less than the threshold voltage of the driving transistor DT of the pixel circuit corresponding to the light-emitting device with low luminous efficiency, it is acceptable.

[0085] Next, the first type of light-emitting device EL1 is taken as a green light-emitting device, and the second type of light-emitting device EL2 includes a red light-emitting device and a blue light-emitting device as an example for detailed explanation.

[0086] As shown in Figure 1 or Figure 4 The second type of light-emitting device EL2 includes a first type of sub-light-emitting device EL21 and a second type of sub-light-emitting device EL22. The first type of sub-light-emitting device EL21 is a red light-emitting device, and the second type of sub-light-emitting device EL22 is a blue light-emitting device. The second type of pixel circuit PDCA2 includes a first type of sub-pixel circuit PDCA21 and a second type of sub-pixel circuit PDCA22. One first type of sub-light-emitting device EL21 is connected with one first type of sub-pixel circuit PDCA21, and one second type of sub-light-emitting device EL22 is connected with one second type of sub-pixel circuit PDCA22.

[0087] At this time, as shown in Figure 4As shown, the conductive layer BSM includes a second conductive sheet BSM2 and a third conductive sheet BSM3, the positive projection of the driving transistor of the first type of sub-pixel circuit PDCA21 has an overlapping area with the positive projection of the second conductive sheet BSM2, the second conductive sheet BSM2 is used to load a second voltage signal to increase the threshold voltage of the driving transistor DT of the first type of sub-pixel circuit PDCA21; the positive projection of the driving transistor of the second type of sub-pixel circuit PDCA22 has an overlapping area with the positive projection of the third conductive sheet BSM3, the third conductive sheet BSM3 is used to load a third voltage signal to increase the threshold voltage of the driving transistor DT of the second type of sub-pixel circuit PDCA22.

[0088] In this way, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 is reduced by the first voltage signal loaded on the first conductive sheet BSM1, the threshold voltage of the driving transistor DT of the first type of sub-pixel circuit PDCA21 is increased by the second voltage signal loaded on the second conductive sheet BSM2, and the threshold voltage of the driving transistor DT of the second type of sub-pixel circuit PDCA22 is increased by the third voltage signal loaded on the third conductive sheet BSM3, so as to ensure that the increase amplitude of the current of the first type of light emitting device EL1 is less than the increase amplitude of the current of the first type of sub-light emitting device EL21 and less than the increase amplitude of the current of the second type of sub-light emitting device EL22 after the reliability test, and further ensure that the luminous brightness of the first type of light emitting device EL1, the luminous brightness of the first type of sub-light emitting device EL21, and the luminous brightness of the second type of sub-light emitting device EL22 are close in the case that the luminous efficiency of the first type of light emitting device EL1 is greater than the luminous efficiency of the first type of sub-light emitting device EL21 and greater than the luminous efficiency of the second type of sub-light emitting device EL22, so as to weaken the phenomenon of bright green in the display panel in use, and further ensure the display effect of the display panel.

[0089] In this way, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 is reduced by the first voltage signal loaded on the first conductive sheet BSM1, the threshold voltage of the driving transistor DT of the first type of sub-pixel circuit PDCA21 is increased by the second voltage signal loaded on the second conductive sheet BSM2, and the threshold voltage of the driving transistor DT of the second type of sub-pixel circuit PDCA22 is increased by the third voltage signal loaded on the third conductive sheet BSM3, so as to ensure that the increase amplitude of the current of the first type of light emitting device EL1 is less than the increase amplitude of the current of the first type of sub-light emitting device EL21 and less than the increase amplitude of the current of the second type of sub-light emitting device EL22 after the reliability test, and further ensure that the luminous brightness of the first type of light emitting device EL1, the luminous brightness of the first type of sub-light emitting device EL21, and the luminous brightness of the second type of sub-light emitting device EL22 are close in the case that the luminous efficiency of the first type of light emitting device EL1 is greater than the luminous efficiency of the first type of sub-light emitting device EL21 and greater than the luminous efficiency of the second type of sub-light emitting device EL22, so as to weaken the phenomenon of bright green in the display panel in use, and further ensure the display effect of the display panel.

[0090] For example, the first type of light emitting device EL1, the first type of sub light emitting device EL21, and the second type of sub light emitting device EL22 are arranged in the row direction in turn and alternately. At this time, for a column of the first type of sub light emitting device EL21 and the second type of sub light emitting device EL22 arranged in the column direction, the corresponding second conductive sheet BSM2 and the third conductive sheet BSM3 are as shown in Figure 5 .

[0091] Alternatively, taking the second conductive sheet BSM2 as an example, the orthographic projection of the driving transistor of the first type of sub-pixel circuit PDCA21 can partially coincide with the orthographic projection of the second conductive sheet BSM2, or the orthographic projection of the driving transistor of the first type of sub-pixel circuit PDCA21 can be located within the orthographic projection of the second conductive sheet BSM2. The present embodiment does not limit this, as long as the second voltage signal loaded on the second conductive sheet BSM2 can adjust the threshold voltage of the driving transistor DT of the first type of sub-pixel circuit PDCA21.

[0092] For example, the orthographic projection of the driving transistor of the first type of sub-pixel circuit PDCA21 is located within the orthographic projection of the second conductive sheet BSM2. At this time, in combination with the case that the first active part of the driving transistor is formed in the active layer ACT as described above, the orthographic projection of the first active part of the first type of sub-pixel circuit PDCA21 is located within the orthographic projection of the second conductive sheet BSM2.

[0093] In combination with the case that the first type of sub light emitting device EL21 is a red light emitting device and the second type of sub light emitting device EL22 is a blue light emitting device as described above, since the light emitting efficiency of the red light emitting device and the blue light emitting device is approximately the same, in this way, the same voltage signal can be loaded on the second conductive sheet BSM2 and the third conductive sheet BSM3, that is, the second voltage signal loaded on the second conductive sheet BSM2 and the third voltage signal loaded on the third conductive sheet BSM3 can be the same voltage signal, ensuring that the increase amplitude of the current of the first type of sub light emitting device EL21 and the increase amplitude of the current of the second type of sub light emitting device EL22 are the same, and further ensuring that the light emitting brightness of the first type of sub light emitting device EL21 and the light emitting brightness of the second type of sub light emitting device EL22 are more close.

[0094] Of course, the second voltage signal loaded on the second conductive sheet BSM2 and the third voltage signal loaded on the third conductive sheet BSM3 can also be different, as long as the threshold voltage of the driving transistor DT of the first type of sub-pixel circuit PDCA21 and the threshold voltage of the driving transistor DT of the second type of sub-pixel circuit PDCA22 are not too different. The present embodiment does not limit this.

[0095] Alternatively, for the case that the second voltage signal and the third voltage signal are the same voltage signal, as shown in Figure 4 or Figure 5As shown, the second conductive sheet BSM2 and the third conductive sheet BSM3 are on the same layer and are an integral structure.

[0096] Optionally, if the second voltage signal and the third voltage signal are the same voltage signal, in conjunction with the above description, the driving layer DR is formed with a power signal line for loading the power signal and an initial voltage signal line for loading the initial voltage signal. Figure 3 As shown in Figure 5, the power signal line is connected to the first conductive sheet BSM1, and the initial voltage signal line is connected to the second conductive sheet BSM2 and the third conductive sheet BSM3. Thus, by applying the power signal VDD to the first conductive sheet BSM1, the threshold voltage of the driving transistor DT of the first type pixel circuit PDCA1 is reduced; by applying the initial voltage signal Vinit to the second conductive sheet BSM2, the threshold voltage of the driving transistor DT of the first type sub-pixel circuit PDCA21 is increased; and by applying the initial voltage signal Vinit to the third conductive sheet BSM3, the threshold voltage of the driving transistor DT of the second type sub-pixel circuit PDCA22 is increased, ensuring that the luminous brightness of the first type light-emitting device EL1, the first type sub-light-emitting device EL21, and the second type sub-light-emitting device EL22 is close.

[0097] For example, after the first conductive sheet BSM1 is loaded with a power supply signal VDD, and the second conductive sheet BSM2 and the third conductive sheet BSM3 are both loaded with an initial voltage signal Vinit, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 and the threshold voltage of the driving transistor of the second type of pixel circuit PDCA2 change with time as shown in the curves. Figure 6 As shown, at any given time point, the threshold voltage of the driving transistor DT of the first type of pixel circuit PDCA1 is less than the threshold voltage of the driving transistor DT of the second type of pixel circuit PDCA2, thereby ensuring that the luminous brightness of the first type of light-emitting device EL1 is closer to that of the second type of light-emitting device EL2.

[0098] Optionally, for the case where the conductive layer BSM includes a first conductive sheet BSM1 and a second conductive sheet BSM2, such as... Figure 4 As shown, the first conductive sheet BSM1 and the second conductive sheet BSM2 can be disposed in the same layer; of course, in other embodiments, the first conductive sheet BSM1 and the second conductive sheet BSM2 are disposed in different layers. For example, the conductive layer BSM includes the first conductive layer BSM and the second conductive layer BSM, and an insulating layer located between the first conductive layer BSM and the second conductive layer BSM. The first conductive layer BSM includes the first conductive sheet BSM1, and the second conductive layer BSM includes the second conductive sheet BSM2.

[0099] In combination with the above-mentioned second conductive sheet BSM2 and third conductive sheet BSM3 being arranged in the same layer, and the first conductive sheet BSM1 and second conductive sheet BSM2 being arranged in the same layer, the first conductive sheet BSM1, second conductive sheet BSM2, and third conductive sheet BSM3 are arranged in the same layer.

[0100] Figure 7 A flowchart of a manufacturing method of a display panel is shown as an example of the manufacturing method of the display panel according to the embodiments of the present disclosure. The method is used to manufacture the display panel described in the above embodiments, and the method includes the following steps S710-S740.

[0101] In step S710, a substrate is provided.

[0102] In step S720, a conductive layer is manufactured, and the conductive layer includes a first conductive sheet, and the first conductive sheet is used to load a first voltage signal.

[0103] In step S730, a driving layer is manufactured on a side of the conductive layer away from the substrate, and the driving layer includes a first type of pixel circuit and a second type of pixel circuit.

[0104] The orthographic projection of the driving transistor of the first type of pixel circuit and the orthographic projection of the first conductive sheet have an overlapping area, and the orthographic projection of the driving transistor of the second type of pixel circuit and the orthographic projection of the first conductive sheet do not have an overlapping area.

[0105] In step S740, a light-emitting layer is manufactured on a side of the driving layer away from the substrate, and the light-emitting layer includes a first type of light-emitting device and a second type of light-emitting device. A first type of light-emitting device is connected to a first type of pixel circuit, and a second type of light-emitting device is connected to a second type of pixel circuit. The first type of light-emitting device and the second type of light-emitting device have different light-emitting efficiencies.

[0106] In step S720, the first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit when the light-emitting efficiency of the first type of light-emitting device is higher than the light-emitting efficiency of the second type of light-emitting device, or to be greater than the threshold voltage of the driving transistor of the second type of pixel circuit when the light-emitting efficiency of the first type of light-emitting device is lower than the light-emitting efficiency of the second type of light-emitting device.

[0107] In the embodiments of the present disclosure, by arranging the first conductive sheet and adjusting the threshold voltage of the driving transistor of the first type of pixel circuit based on the additional electric field formed by the first voltage signal loaded on the first conductive sheet, the increase amplitude of the current of the first type of light emitting device is different from the increase amplitude of the current of the second type of light emitting device after the reliability test. In combination with the fact that the luminous efficiency of the first type of light emitting device is different from the luminous efficiency of the second type of light emitting device, the luminous brightness of the first type of light emitting device is closer to the luminous brightness of the second type of light emitting device, so as to weaken the phenomenon of bright green of the display panel in use, and further ensure the display effect of the display panel.

[0108] Optionally, the manufacturing processes of the above steps S710, S730 and S740 can refer to related technologies, and the only difference is that, in the step S730 of manufacturing the driving layer, it is only required to ensure that the driving transistor of the first type of pixel circuit is directly above the first conductive sheet, that is, the driving transistor of the first type of pixel circuit has a projection area overlapping the projection area of the first conductive sheet, and the driving transistor of the second type of pixel circuit has no projection area overlapping the projection area of the first conductive sheet.

[0109] The conductive layer manufactured in the step S720 described above includes only the first conductive sheet in some embodiments, and includes the first conductive sheet, the second conductive sheet and the third conductive sheet in other embodiments. For the case of including the second conductive sheet and the third conductive sheet, in combination with the display panel described in the above embodiments, in the step S730 of manufacturing the driving layer, it is only required to ensure that the driving transistor of the first type of sub-pixel circuit is directly above the second conductive sheet, and the driving transistor of the second type of sub-pixel circuit is directly above the third conductive sheet.

[0110] It should be noted that although the steps of the manufacturing method of the display panel in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that these steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired result. Additionally or alternatively, some steps can be omitted, a plurality of steps can be combined into one step, and / or one step can be divided into a plurality of steps, etc.

[0111] The embodiments of the present disclosure also provide a display device including the display panel described in the above embodiments. Thus, for the display device including the display panel described above, the problem of bright green in displaying a picture can be avoided to improve the picture display effect.

[0112] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A display panel, characterized in that, include: substrate; A driving layer is located on one side of the substrate and has a first type of pixel circuit and a second type of pixel circuit formed thereon, both of which include driving transistors. A light-emitting layer is located on the side of the driving layer away from the substrate, and a first type of light-emitting device and a second type of light-emitting device are formed thereon. A first type of light-emitting device is connected to a first type of pixel circuit, and a second type of light-emitting device is connected to a second type of pixel circuit. The first type of light-emitting device and the second type of light-emitting device have different luminous efficiencies. A conductive layer is located between the substrate and the driving layer, and includes a first conductive sheet. The orthographic projection of the driving transistor of the first type of pixel circuit and the orthographic projection of the first conductive sheet have an overlapping area, and the orthographic projection of the second type of pixel circuit and the orthographic projection of the first conductive sheet do not have an overlapping area. The first conductive sheet is used to load a first voltage signal. The first voltage signal applied to the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit when the luminous efficiency of the first type of light-emitting device is higher than that of the second type of light-emitting device, or to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be greater than that of the driving transistor of the second type of pixel circuit when the luminous efficiency of the first type of light-emitting device is lower than that of the second type of light-emitting device.

2. The display panel as described in claim 1, characterized in that, The first type of light-emitting device is a green light-emitting device, and the first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit.

3. The display panel as described in claim 2, characterized in that, The second type of pixel circuit includes a first type of sub-pixel circuit and a second type of sub-pixel circuit; the second type of light-emitting device includes a first type of sub-light-emitting device and a second type of sub-light-emitting device. The first type of sub-light-emitting device is a red light-emitting device, the second type of sub-light-emitting device is a blue light-emitting device, a first type of sub-light-emitting device is connected to a first type of sub-pixel circuit, and a second type of sub-light-emitting device is connected to a second type of sub-pixel circuit. The conductive layer includes a second conductive sheet and a third conductive sheet. The orthographic projection of the driving transistor of the first type of sub-pixel circuit overlaps with the orthographic projection of the second conductive sheet. The second conductive sheet is used to load a second voltage signal to increase the threshold voltage of the driving transistor of the first type of sub-pixel circuit. The orthographic projection of the driving transistor of the second type of sub-pixel circuit overlaps with the orthographic projection of the third conductive sheet. The third conductive sheet is used to load a third voltage signal to increase the threshold voltage of the driving transistor of the second type of sub-pixel circuit.

4. The display panel as described in claim 3, characterized in that, The second conductive sheet and the third conductive sheet are on the same layer and are an integral structure. The second voltage signal and the third voltage signal are the same voltage signal.

5. The display panel as described in claim 4, characterized in that, The first conductive sheet and the second conductive sheet are disposed in the same layer.

6. The display panel as described in claim 4, characterized in that, The driving layer is formed with power signal lines and initial voltage signal lines; The power signal line is connected to the first conductive plate, and the initial voltage signal line is connected to the second and third conductive plates.

7. The display panel as described in any one of claims 1-6, characterized in that, The driving layer includes: An active layer is located on the side of the conductive layer opposite to the substrate, and includes a first active portion, the first active portion including a first channel region and a first connection portion and a second connection portion located on both sides of the first channel region. A gate metal layer is located on the side of the active layer away from the substrate and includes a first conductive portion, wherein the first conductive portion and the first channel region have an overlapping area in a direction perpendicular to the substrate. A source / drain metal layer is located on the side of the gate metal layer away from the substrate, and includes a first connection line. A first end of the first connection line is electrically connected to the first connection portion, and a second end of the first connection line is electrically connected to the light-emitting device. The first connecting portion and the second connecting portion respectively form the first electrode and the second electrode of the driving transistor. The area on the first conductive portion that overlaps with the first channel region forms the control electrode of the driving transistor. The orthographic projection of the first active portion included in the first type of pixel circuit is located within the orthographic projection of the first conductive sheet.

8. The display panel as described in claim 7, characterized in that, The second type of pixel circuit includes a first type of sub-pixel circuit and a second type of sub-pixel circuit, and the conductive layer includes a second conductive sheet and a third conductive sheet; The orthographic projection of the first active portion of the first type of sub-pixel circuit is located within the orthographic projection of the second conductive sheet, and the orthographic projection of the first active portion of the second type of sub-pixel circuit is located within the orthographic projection of the third conductive sheet.

9. A method for manufacturing a display panel, characterized in that, The method includes: Provide a substrate; A conductive layer is fabricated, the conductive layer including a first conductive sheet, the first conductive sheet being used to load a first voltage signal; A driving layer is formed on the side of the conductive layer away from the substrate. The driving layer includes a first type of pixel circuit and a second type of pixel circuit. The orthographic projection of the driving transistor of the first type of pixel circuit overlaps with the orthographic projection of the first conductive sheet, while the orthographic projection of the driving transistor of the second type of pixel circuit does not overlap with the orthographic projection of the first conductive sheet. A light-emitting layer is formed on the side of the driving layer away from the substrate. The light-emitting layer includes a first type of light-emitting device and a second type of light-emitting device. A first type of light-emitting device is connected to a first type of pixel circuit, and a second type of light-emitting device is connected to a second type of pixel circuit. The first type of light-emitting device and the second type of light-emitting device have different luminous efficiencies. The first voltage signal loaded on the first conductive sheet is used to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be less than the threshold voltage of the driving transistor of the second type of pixel circuit when the luminous efficiency of the first type of light-emitting device is higher than that of the second type of light-emitting device, or to adjust the threshold voltage of the driving transistor of the first type of pixel circuit to be greater than that of the driving transistor of the second type of pixel circuit when the luminous efficiency of the first type of light-emitting device is lower than that of the second type of light-emitting device.

10. A display device, characterized in that, The display device includes the display panel described in any one of claims 1-8.

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