Display panel and display terminal

Abstract

The invention relates to a display panel and a display terminal. The display panel comprises a plurality of sub-pixels, at least one sub-pixel comprises a pixel circuit, and the pixel circuit comprises a driving transistor and a switching transistor which are connected. Wherein the sub-threshold swing of the driving transistor is greater than that of the switching transistor. In the display panel provided by the embodiment of the invention, the sub-threshold swing of the driving transistor is set to be greater than the sub-threshold swing of the switching transistor, and when the display panel displays a low-gray-scale picture, the sub-threshold swing of the driving transistor is relatively large, so that small change of grid voltage does not cause great change of current, the current can be accurately controlled, and the display effect is improved. And the phenomenon of non-uniform brightness of a low-gray-scale picture is improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a display terminal. Background Art

[0002] With the rapid development of high-power display products such as wearable displays, reducing power consumption has become a key industry development direction. Against this backdrop, LTPO (low-temperature polycrystalline oxide) technology has emerged, combining the high mobility of LTPS (low-temperature polycrystalline silicon) with the low leakage current of IGZO (indium gallium zinc oxide). LTPO technology combines fast response and energy efficiency, but its industrialization remains challenging due to complex manufacturing processes and high costs.

[0003] Oxide thin-film transistors (TFTs), with their low leakage current advantage, have become a preferred solution for developing ultra-low power display panels. However, when used as driver transistors, oxide TFTs are prone to uneven brightness when displaying low grayscale images. This phenomenon is particularly noticeable in dark scenes or areas with grayscale gradients, seriously affecting display quality. Summary of the Invention

[0004] Embodiments of the present application provide a display panel and a display terminal to improve the technical problem that when oxide thin film transistors are used as driving transistors, the display panel is prone to uneven brightness when displaying low grayscale images.

[0005] To achieve the above object, according to a first aspect of the present application, a display panel is provided, comprising a plurality of sub-pixels, at least one of the sub-pixels comprising a pixel circuit, the pixel circuit comprising a driving transistor and a switching transistor connected thereto;

[0006] Wherein, the subthreshold swing of the driving transistor is greater than the subthreshold swing of the switching transistor.

[0007] Optionally, a gate oxide capacitance of the driving transistor is smaller than a gate oxide capacitance of the switching transistor.

[0008] Optionally, the display panel includes:

[0009] substrate;

[0010] an active layer disposed on one side of the substrate, the active layer comprising a driving active portion of the driving transistor and a switching active portion of the switching transistor;

[0011] a gate layer, provided on a side of the active layer away from the substrate, the gate layer comprising a driving gate of the driving transistor and a switching gate of the switching transistor;

[0012] Wherein, in the thickness direction of the display panel, the distance between the driving gate and the driving active portion is greater than the distance between the switching gate and the switching active portion.

[0013] Optionally, a first gate insulating layer is provided between the driving gate and the driving active portion, a second gate insulating layer is provided between the switch gate and the switch active portion, and a thickness of the first gate insulating layer is greater than a thickness of the second gate insulating layer.

[0014] Optionally, the second gate insulating layer includes a first sublayer, and the first gate insulating layer includes a stacked first sublayer and a second sublayer;

[0015] Wherein, in the thickness direction of the display panel, the second sub-layer is arranged between the driving gate and the switching gate, and the thickness of the first sub-layer is greater than or equal to the thickness of the second sub-layer.

[0016] Optionally, a first gate insulating layer is provided between the driving gate and the driving active portion, a second gate insulating layer is provided between the switch gate and the switch active portion, and the dielectric constant of the first gate insulating layer is smaller than the dielectric constant of the second gate insulating layer.

[0017] Optionally, the display panel includes:

[0018] substrate;

[0019] an active layer disposed on one side of the substrate, the active layer comprising a driving active portion of the driving transistor and a switching active portion of the switching transistor;

[0020] a gate layer, provided on a side of the active layer away from the substrate, the gate layer comprising a driving gate of the driving transistor and a switching gate of the switching transistor;

[0021] a source-drain electrode layer, disposed on a side of the gate away from the substrate, the source-drain electrode layer including a driving source electrode of the driving transistor;

[0022] a conductive layer, disposed on a side of the active layer close to the substrate, the conductive layer comprising a first conductive portion corresponding to the driving transistor and a second conductive portion corresponding to the switching transistor;

[0023] The driving source is connected to the first conductive part, and the switch gate receives the same input signal as the second conductive part.

[0024] Optionally, the driving active portion and the switching active portion are both oxide semiconductors.

[0025] Optionally, the display panel includes a capacitor provided on one side of the substrate, and the capacitor includes a stacked first electrode plate and a second electrode plate;

[0026] The first electrode plate and the driving gate are arranged on the same layer, and the second electrode plate and the switch gate are arranged on the same layer.

[0027] According to a second aspect of the present application, a display terminal is provided, comprising the above-mentioned display panel.

[0028] In the display panel of the embodiment of the present application, by setting the subthreshold swing of the driving transistor to be larger than the subthreshold swing of the switching transistor, when the display panel displays a low grayscale image, the subthreshold swing of the driving transistor is larger, and a slight change in the gate voltage will not cause a large change in the current, thereby accurately controlling the current and improving the uneven brightness phenomenon when displaying low grayscale images.

[0029] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0031] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0032] Figure 1 is a schematic top view of a display panel provided in an exemplary embodiment of the present disclosure;

[0033] Figure 2 yes Figure 1 Schematic diagram of the cross-section structure at CC;

[0034] Figure 3 is a schematic diagram of a pixel circuit provided in an exemplary embodiment of the present disclosure;

[0035] Figure 4 It is a characteristic curve diagram of two transistors with different subthreshold swings;

[0036] Figure 5 2 is a schematic structural diagram of a display terminal provided in an exemplary embodiment of the present disclosure.

[0037] Description of reference numerals:

[0038] 1-display panel; AA-display area; NA-non-display area; 1a-sub-pixel; 10a-light-emitting unit; 101-anode; 102-light-emitting material layer; 103-cathode;

[0039] 10-Substrate;

[0040] 20 - driving transistor; 21 - driving active portion; 22 - driving gate; 23 - driving source; 24 - first conductive portion; 25 - driving drain;

[0041] 30 - switch transistor; 31 - switch active portion; 32 - switch gate; 33 - second conductive portion;

[0042] 40-active layer;

[0043] 50-gate layer;

[0044] 60-source and drain layer;

[0045] 70-conductive layer;

[0046] 81 - first gate insulating layer; 82 - second gate insulating layer; 801 - first sublayer; 802 - second sublayer;

[0047] 91-first electrode plate; 92-second electrode plate;

[0048] d1-the distance between the driving gate 22 and the driving active part 21;

[0049] d2 - the distance between the switch gate 32 and the switch active portion 31;

[0050] 2-Display terminal; 3-Terminal body. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0052] According to the first aspect of this application, Figures 1 to 4 As shown, a display panel 1 is provided, comprising a plurality of sub-pixels 1a, at least one sub-pixel 1a comprising a pixel circuit, the pixel circuit comprising a driving transistor 20 and a switching transistor 30 connected thereto; wherein the subthreshold swing of the driving transistor 20 is greater than the subthreshold swing of the switching transistor 30.

[0053] The display panel 1 may be an LCD panel, an OLED panel, a Mini-LED panel, a Micro-LED panel, etc.

[0054] like Figure 1 As shown, the display panel 1 includes a display area AA and a non-display area NA disposed peripherally to the display area AA. The display area AA may be provided with a plurality of sub-pixels 1a, including red, green, and blue sub-pixels 1a, thereby achieving color display. The non-display area NA may be provided with a driving circuit, such as a gate driving circuit, which may provide driving signals to the sub-pixels 1a.

[0055] The driving transistor 20 (Driving TFT) and the switching transistor 30 (Switch TFT) may both be thin film transistors.

[0056] In the display area AA, in order to drive the sub-pixel 1a to display, each sub-pixel 1a includes a corresponding pixel circuit. According to the number of thin-film transistors, the pixel circuit can be divided into 2T1C, 3T1C, 4T1C, 5T1C, 6T1C, 7T1C, 8T2C and other driving architectures. Among them, T represents thin-film transistor and C represents capacitor. 2T means that there are two thin-film transistors in the pixel circuit, and 1C means that there is one capacitor in the pixel circuit. The names and meanings of other driving circuits are similar.

[0057] Figure 3 The 4T2C pixel circuit is used as an example for explanation, which should not be understood as limiting the embodiments of the present application. Figure 3 , four thin film transistors are shown, numbered T1 to T4, and two capacitors are shown, C1 and C2. C1 is a storage capacitor in the pixel circuit. VDD and VSS are power supplies, and Vdata is a data signal.

[0058] The driving transistor 20 is used to provide a stable driving current for the load. The driving transistor 20 can be Figure 3 The source of the driving transistor 20 can be directly or indirectly connected to the power supply VDD, and the drain of the driving transistor 20 can be directly or indirectly connected to the load. The gate of the driving transistor 20 is connected to one plate of the storage capacitor C1, and the drain of the driving transistor 20 is connected to the other plate of the storage capacitor C1. When the display panel 1 is an LCD panel, the load can be a pixel electrode. When the display panel 1 is an OLED panel, a Mini-LED panel, or a Micro-LED panel, the load is OLED, Mini-LED, or Micro-LED, respectively.

[0059] like Figure 3As shown, the switch transistor 30 is used to realize circuit on-off control, such as signal transmission and timing switching. The switch transistor 30 can be Figure 3 The transistor T1 in FIG. A switching transistor 30 can be used for data write control. The gate of the switching transistor 30 can be connected to the gate scan signal Sn, and the source of the switching transistor 30 can be connected to the data signal Vdata. The drain of the switching transistor 30 can be connected to a plate of the storage capacitor C1 and the gate of the driving transistor 20. The switching transistor 30 is used to control the data signal input to the storage capacitor C1, so that the storage capacitor C1 is charged to an appropriate potential.

[0060] Subthreshold swing refers to the current I when the transistor is in the subthreshold region. ds With V gs The subthreshold region refers to the transition region between the transistor's "off state" and "on state". In the subthreshold region, V gs Close to V th , usually V gs <V th At this time, the active part of the thin film transistor is not fully turned on, but there are a small number of carriers (electrons or holes) forming a weak conductive channel, I ds With V gs It grows exponentially. Among them, V gs is the difference between the gate voltage and the source voltage of the thin film transistor, V th is the threshold voltage of the thin film transistor, I ds It is the current between the source and drain of the thin film transistor.

[0061] like Figure 4 As shown, the horizontal axis is V gs , the vertical axis is I ds . Figure 4 Figure 2 shows the characteristic curves of two transistors with different subthreshold swings. The black curve is the characteristic curve of the transistor with a smaller subthreshold swing, and the gray curve is the characteristic curve of the transistor with a larger subthreshold swing. As shown by the black curve, when the subthreshold swing is small, a small change in the gate voltage ΔU will cause a large change in the current, making it difficult to accurately control the current. When the display panel 1 displays a low grayscale image, the operating current is small. Slight changes in the current will cause changes in the display brightness, resulting in uneven brightness of the display panel 1 when displaying low grayscale images.

[0062] As shown in the gray curve, when the subthreshold swing is large, the current change caused by the same gate voltage change is smaller, so that the current can be adjusted more accurately at low grayscales, reducing the display brightness difference, thereby improving the brightness unevenness of the display panel 1 when displaying at low grayscales.

[0063] In other words, when the current needs to be adjusted within the same range, the change value of the gate voltage of the black curve is ΔU, and the change value of the gate voltage of the gray curve is ΔU', ΔU'>ΔU, that is, under the same change in gate voltage, the change value of the current in the gray curve is smaller than the change value of the current in the black curve, thereby more accurately controlling the current and improving the uneven brightness of the display panel 1 when displaying low grayscale.

[0064] The formula for subthreshold swing is:

[0065] SS=(kT / q)*ln10*(1+C dep / C ox ) formula (1),

[0066] Where SS is the subthreshold swing, k is the Boltzmann constant, and the value of k is 1.38*10 -23 J / K, T is the absolute temperature (unit: K, room temperature is about 300K), q is the electron charge, and the value of q is 1.6*10 -19 C, C dep is the depletion layer capacitance (unit: F / cm 2 ), C ox is the gate oxide capacitance (unit: F / cm 2 ).

[0067] In some embodiments, as Figure 1 and Figure 2 As shown, the display panel 1 includes a light-emitting unit 10a, which is arranged on the side of the driving transistor 20 away from the substrate 10; the drain of the driving transistor 20 is electrically connected to the light-emitting unit 10a. The light-emitting unit 10a can be OLED, Mini-LED, Micro-LED, etc.

[0068] Specifically, if Figure 2 As shown, the light-emitting unit 10a may include a stacked anode 101, a light-emitting material layer 102, and a cathode 103. The drain of the driving transistor 20 may be directly or indirectly electrically connected to the anode 101 of the light-emitting unit 10a. Direct connection means that the anode 101 of the light-emitting unit 10a and the driving transistor 20 are not separated by other components such as thin-film transistors. Indirect connection means that the anode 101 of the light-emitting unit 10a and the driving transistor 20 are separated by other thin-film transistors. When the thin-film transistor is in the on state, the anode 101 of the light-emitting unit 10a and the driving transistor 20 can be electrically connected.

[0069] Optionally, the gate oxide capacitance of the driving transistor 20 is smaller than the gate oxide capacitance of the switching transistor 30 .

[0070] As shown in the formula (1) of subthreshold swing, SS and gate oxide capacitance Cox In inverse proportion, by making the gate oxide capacitance of the driving transistor 20 smaller than the gate oxide capacitance of the switching transistor 30, the subthreshold swing of the driving transistor 20 can be increased while other conditions remain unchanged.

[0071] Gate Oxide Capacitance (C ox ) is the capacitance formed between the gate and the channel of the transistor through the insulating layer.

[0072] The formula for gate oxide capacitance is:

[0073] C ox =ε ox / t ox Formula (2),

[0074] Among them, ε ox is the absolute dielectric constant of the gate insulating layer (unit: F / cm), which is determined by the material properties. ox is the thickness of the gate insulating layer (unit: cm).

[0075] Alternatively, as Figure 2 As shown, the display panel 1 includes a substrate 10, an active layer 40 and a gate layer 50. The active layer 40 is arranged on one side of the substrate 10, and the active layer 40 includes a driving active portion 21 of the driving transistor 20 and a switching active portion 31 of the switching transistor 30; the gate layer 50 is arranged on a side of the active layer 40 away from the substrate 10, and the gate layer 50 includes a driving gate 22 of the driving transistor 20 and a switching gate 32 of the switching transistor 30; wherein, in the thickness direction of the display panel 1, the distance d1 between the driving gate 22 and the driving active portion 21 is greater than the distance d2 between the switching gate 32 and the switching active portion 31.

[0076] In some embodiments, the substrate 10 may be made of a rigid material or a flexible material. The rigid material may be a glass substrate, a quartz substrate, or a silicon wafer. The flexible material may be one of colorless polyimide (PI), polycarbonate (PC), polynorbornene (PNB), and polyethylene terephthalate (PET).

[0077] In some embodiments, as Figure 2 As shown, the driving active part 21 and the switching active part 31 can be provided in the same layer and made of the same material, thereby simplifying the manufacturing process of the display panel 1 .

[0078] In other embodiments, the driving active portion 21 and the switching active portion 31 may be provided in different layers.

[0079] In some embodiments, as Figure 2As shown, the driving gate 22 and the switching gate 32 can be provided in the same layer and made of the same material, thereby simplifying the manufacturing process of the display panel 1 .

[0080] In other embodiments, the driving gate 22 and the switch gate 32 may be provided in different layers.

[0081] In the thickness direction of the display panel 1 , the distance d1 between the driving gate 22 and the driving active portion 21 refers to the distance between the side surface of the driving gate 22 close to the driving active portion 21 and the side surface of the driving active portion 21 close to the driving gate 22 .

[0082] In the thickness direction of the display panel 1 , the distance d2 between the switch gate 32 and the switch active portion 31 refers to the distance between the side surface of the switch gate 32 close to the switch active portion 31 and the side surface of the switch active portion 31 close to the switch gate 32 .

[0083] As can be seen from formula (2) of the gate oxide capacitance, the gate oxide capacitance is inversely proportional to the distance between the gate and the active portion. By setting the distance d1 between the driving gate 22 and the driving active portion 21 to be greater than the distance d2 between the switch gate 32 and the switch active portion 31, the gate oxide capacitance of the driving transistor 20 can be reduced, thereby increasing the subthreshold swing of the driving transistor 20.

[0084] Optionally, a first gate insulating layer 81 is provided between the driving gate 22 and the driving active portion 21 , and a second gate insulating layer 82 is provided between the switch gate 32 and the switch active portion 31 . The thickness of the first gate insulating layer 81 is greater than that of the second gate insulating layer 82 .

[0085] The material of the first gate insulating layer 81 can be one or a stack of multiple insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride.

[0086] The second gate insulating layer 82 may be made of one or more insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride.

[0087] In some embodiments, the material of the first gate insulating layer 81 and the material of the second gate insulating layer 82 may be the same.

[0088] In some other embodiments, the material of the first gate insulating layer 81 and the material of the second gate insulating layer 82 may be different.

[0089] like Figure 2 As shown, a first gate insulating layer 81 is provided between the driving gate 22 and the driving active portion 21. The first gate insulating layer 81 serves as the gate insulating layer of the driving transistor 20, and the second gate insulating layer 82 serves as the gate insulating layer of the switching transistor 30. In other words, the thickness of the first gate insulating layer 81 is equal to the thickness of the driving transistor 20. oxThe thickness of the second gate insulating layer 82 is t ox .

[0090] According to formula (2) of the gate oxide capacitance, by making the thickness of the first gate insulating layer 81 greater than the thickness of the second gate insulating layer 82, the gate oxide capacitance of the driving transistor 20 can be made smaller than the gate oxide capacitance of the switching transistor 30, thereby reducing the gate oxide capacitance of the driving transistor 20 and increasing the subthreshold swing of the driving transistor 20.

[0091] Alternatively, as Figure 2 As shown, the second gate insulating layer 82 includes a first sublayer 801, and the first gate insulating layer 81 includes a stacked first sublayer 801 and a second sublayer 802; wherein, in the thickness direction of the display panel 1, the second sublayer 802 is arranged between the driving gate 22 and the switching gate 32, and the thickness of the first sublayer 801 is greater than or equal to the thickness of the second sublayer 802.

[0092] The material of the first sub-layer 801 can be a stack of one or more insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride.

[0093] The material of the second sub-layer 802 can be a stack of one or more insulating materials such as silicon oxide, silicon nitride, and silicon oxynitride.

[0094] In some embodiments, the material of the first sub-layer 801 may be the same as the material of the second sub-layer 802 .

[0095] In other embodiments, the material of the first sub-layer 801 may be different from the material of the second sub-layer 802 .

[0096] The second gate insulating layer 82 includes a first sublayer 801, and the first gate insulating layer 81 includes a stacked first sublayer 801 and a second sublayer 802. In other words, the second gate insulating layer 82 is a single insulating layer, namely the first sublayer 801. The first gate insulating layer 81 is a two-layer insulating layer, namely the first sublayer 801 and the second sublayer 802. Because the first gate insulating layer 81 has an additional second sublayer 802 relative to the second gate insulating layer 82, the thickness of the first gate insulating layer 81 is greater than that of the second gate insulating layer 82.

[0097] In some embodiments, the thickness of the first sublayer 801 is greater than or equal to the thickness of the second sublayer 802. Because the gate insulation layer of the switching transistor 30 is only a single first sublayer 801, a thin thickness of the first sublayer 801 can lead to a risk of leakage in the switching transistor 30. When leakage occurs in the switching transistor 30, the leakage current can charge the storage capacitor of the subpixel 1a, causing the subpixel 1a to light up, thereby causing defects such as bright spots on the display panel 1. Therefore, by setting the thickness of the first sublayer 801 to be greater than the thickness of the second sublayer 802, the risk of bright spots on the display panel 1 can be reduced.

[0098] In some embodiments, the thickness of the first sublayer 801 may be 1000 angstroms to 1500 angstroms. For example, the thickness of the first sublayer 801 may be 1000 angstroms, 1100 angstroms, 1200 angstroms, 1300 angstroms, 1400 angstroms, 1500 angstroms, etc.

[0099] In some embodiments, the thickness of the second sublayer 802 may be 200 angstroms to 1000 angstroms. For example, the thickness of the second sublayer 802 may be 200 angstroms, 300 angstroms, 400 angstroms, 500 angstroms, 600 angstroms, 700 angstroms, 800 angstroms, 900 angstroms, 1000 angstroms, etc.

[0100] Optionally, a first gate insulating layer 81 is provided between the driving gate 22 and the driving active part 21 , and a second gate insulating layer 82 is provided between the switch gate 32 and the switch active part 31 . The dielectric constant of the first gate insulating layer 81 is smaller than the dielectric constant of the second gate insulating layer 82 .

[0101] Since the gate oxide capacitance is proportional to the absolute dielectric constant of the gate insulating layer, the gate oxide capacitance can be reduced by reducing the dielectric constant of the gate insulating layer. In other words, by making the dielectric constant of the first gate insulating layer 81 smaller than the dielectric constant of the second gate insulating layer 82, the gate oxide capacitance of the driving transistor 20 can be made smaller than the gate oxide capacitance of the switching transistor 30. This reduces the gate oxide capacitance of the driving transistor 20, thereby increasing the subthreshold swing of the driving transistor 20.

[0102] Alternatively, as Figure 2As shown, the display panel 1 includes a substrate 10, an active layer 40, a gate layer 50, a source-drain layer 60 and a conductive layer 70. The active layer 40 is arranged on one side of the substrate 10, and the active layer 40 includes a driving active portion 21 of the driving transistor 20 and a switching active portion 31 of the switching transistor 30; the gate layer 50 is arranged on a side of the active layer 40 away from the substrate 10, and the gate layer 50 includes a driving gate 22 of the driving transistor 20 and a switching gate 32 of the switching transistor 30; the source-drain layer 60 is arranged on a side of the gate away from the substrate 10, and the source-drain layer 60 includes a driving source 23 of the driving transistor 20; the conductive layer 70 is arranged on a side of the active layer 40 close to the substrate 10, and the conductive layer 70 includes a first conductive portion 24 corresponding to the driving transistor 20 and a second conductive portion 33 corresponding to the switching transistor 30; wherein the driving source 23 is connected to the first conductive portion 24, and the input signals of the switching gate 32 and the second conductive portion 33 are the same.

[0103] In some embodiments, the conductive layer 70 is made of a conductive material, such as a metal. For example, the conductive layer 70 is made of any one selected from molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys thereof.

[0104] like Figure 2 As shown, the first conductive portion 24 is located below the driving active portion 21, and the orthographic projection of the driving active portion 21 on the first conductive portion 24 is located within the first conductive portion 24. The first conductive portion 24 can shield the signal below the driving active portion 21 to prevent the driving transistor 20 from being interfered by external signals.

[0105] like Figure 2 As shown, the second conductive portion 33 is located below the active switch portion 31, and the orthographic projection of the active switch portion 31 on the second conductive portion 33 is located within the second conductive portion 33. The second conductive portion 33 can shield the signal below the active switch portion 31 to prevent the switching transistor 30 from being interfered by external signals.

[0106] like Figure 2 As shown, the first conductive portion 24 and the second conductive portion 33 are separately provided, that is, the first conductive portion 24 and the second conductive portion 33 are not connected, and the first conductive portion 24 and the second conductive portion 33 are insulated from each other.

[0107] like Figure 2 As shown, the driving source 23 is connected to the first conductive portion 24, that is, the driving source 23 and the first conductive portion 24 input the same signal. At this time, only the driving gate 22 controls the channel of the driving transistor 20, that is, the driving transistor 20 has one gate and is a single-gate structure.

[0108] In some embodiments, the driving source electrode 23 and the driving drain electrode 25 are provided in the same layer, thereby simplifying the manufacturing process of the display panel 1. The driving drain electrode 25 can be connected to the light emitting unit 10a.

[0109] like Figure 2 As shown, the switch gate 32 and the second conductive portion 33 receive the same input signal, i.e., the switch gate 32 and the second conductive portion 33 receive the same signal. At this point, the switch gate 32 and the second conductive portion 33 jointly control the channel of the switch transistor 30, i.e., the switch transistor 30 has two gates, forming a dual-gate structure.

[0110] The electric field distribution regulated by the single-gate structure is weak and uneven, resulting in a relatively gentle change in the surface potential of the driving active portion 21. A larger gate voltage change is required to achieve a certain current change, thus increasing the subthreshold swing of the driving transistor 20. The electric field distribution regulated by the dual-gate structure is strong and uniform, resulting in a steeper change in the surface potential of the driving active portion 21. A smaller gate voltage change is required to achieve the same current change, thus reducing the subthreshold swing of the switching transistor 30. The surface potential refers to the difference between the potential at the surface of the active portion and the equilibrium potential within the active portion.

[0111] At the same time, according to the formula (1) for subthreshold swing, when the driving source 23 is connected to the first conductive portion 24, only the driving gate 22 above the driving active portion 21 can serve as the gate of the thin film transistor, while the first conductive portion 24 cannot serve as the gate of the thin film transistor. In this case, the gate oxide capacitance only includes the capacitance corresponding to the top driving gate 22, and does not include the capacitance corresponding to the first conductive portion 24. Therefore, the gate oxide capacitance is smaller, thereby increasing the subthreshold swing.

[0112] When the input signals to the switch gate 32 and the second conductive portion 33 are the same, both serve as the gates of the switch transistor 30, with the switch gate 32 serving as the top gate and the second conductive portion 33 serving as the bottom gate. The gate oxide capacitance is a parallel connection of the capacitance corresponding to the switch gate 32 and the capacitance corresponding to the second conductive portion 33. Consequently, the gate oxide capacitance is significantly increased, thereby reducing the subthreshold swing.

[0113] Through the above configuration, the subthreshold swing of the driving transistor 20 can be made larger than the subthreshold swing of the switching transistor 30 .

[0114] In addition, since the input signal of the switch gate 32 and the second conductive part 33 is the same, it is equivalent to applying the same voltage to the two gates at the same time. The electric fields of the two gates will act together on the channel region, thereby more effectively forming a conductive channel, achieving a higher carrier concentration, and increasing the on-state current I on .

[0115] Optionally, the driving active portion 21 and the switching active portion 31 are both oxide semiconductors.

[0116] In some embodiments, the oxide semiconductor includes any one of IGZO (indium gallium zinc oxide), ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), IGZTO (indium gallium zinc tin oxide), IGO (indium gallium oxide), InO (indium oxide), etc.

[0117] In some embodiments, the driving active portion 21 and the switching active portion 31 are made of the same material, thereby simplifying the manufacturing process of the display panel 1 and reducing the manufacturing cost.

[0118] Alternatively, as Figure 2 As shown, the display panel 1 includes a capacitor arranged on one side of the substrate 10, and the capacitor includes a stacked first plate 91 and a second plate 92; wherein the first plate 91 is arranged on the same layer as the driving gate 22, and the second plate 92 is arranged on the same layer as the switching gate 32.

[0119] In some embodiments, the capacitor can be used as a storage capacitor in the pixel circuit. For example, the capacitor can be Figure 3 C1 in, but not limited to.

[0120] In some embodiments, as Figure 2 As shown, the drive gate 22 and the switch gate 32 are arranged in different layers, that is, the film layers of the drive gate 22 and the switch gate 32 are separated by another insulating film layer. The first electrode plate 91 and the second electrode plate 92 are arranged opposite each other and spaced apart, and the first electrode plate 91 and the second electrode plate 92 are separated by an insulating film layer, thereby forming a capacitor.

[0121] In some embodiments, the first electrode plate 91 and the second electrode plate 92 are separated by a second sub-layer 802. This means that after forming the switch gate 32 and the first electrode plate 91, the entire second sub-layer 802 is formed, and then the drive gate 22 and the second electrode plate 92 are formed on the second sub-layer 802. Because the entire second sub-layer 802 is formed, a photomask is not required, thereby reducing the manufacturing cost of the display panel 1.

[0122] In other embodiments, the first electrode 91 and the second electrode 92 can be formed by any two film layers among the gate layer 50, the source and drain layer 60, the conductive layer 70, and the active layer 40, that is, the first electrode 91 is formed by one of the gate layer 50, the source and drain layer 60, and the conductive layer 70, and the second electrode 92 is formed by the other one of the gate layer 50, the source and drain layer 60, and the conductive layer 70.

[0123] According to the second aspect of this application, Figure 5 As shown, a display terminal 2 is provided, comprising the above-mentioned display panel 1.

[0124] In this embodiment, if Figure 5 As shown, the display terminal 2 includes a display panel 1 and a terminal body 3, and the display panel 1 and the terminal body 3 are combined into one body.

[0125] In this embodiment, the display terminal 2 can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, or a navigator.

[0126] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0127] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0128] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0129] The above are merely preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A display panel, characterized in that: comprising a plurality of sub-pixels, at least one of the sub-pixels comprising a pixel circuit, wherein the pixel circuit comprises a driving transistor and a switching transistor connected to each other; Wherein, the subthreshold swing of the driving transistor is greater than the subthreshold swing of the switching transistor.

2. The display panel according to claim 1, wherein: The gate oxide capacitance of the driving transistor is smaller than the gate oxide capacitance of the switching transistor.

3. The display panel according to claim 2, wherein: The display panel includes: substrate; an active layer disposed on one side of the substrate, the active layer comprising a driving active portion of the driving transistor and a switching active portion of the switching transistor; a gate layer, provided on a side of the active layer away from the substrate, the gate layer comprising a driving gate of the driving transistor and a switching gate of the switching transistor; Wherein, in the thickness direction of the display panel, the distance between the driving gate and the driving active portion is greater than the distance between the switching gate and the switching active portion.

4. The display panel according to claim 3, wherein: A first gate insulating layer is provided between the driving gate and the driving active portion, and a second gate insulating layer is provided between the switch gate and the switch active portion. The thickness of the first gate insulating layer is greater than that of the second gate insulating layer.

5. The display panel according to claim 4, wherein: The second gate insulating layer includes a first sublayer, and the first gate insulating layer includes the first sublayer and a second sublayer stacked; Wherein, in the thickness direction of the display panel, the second sub-layer is arranged between the driving gate and the switching gate, and the thickness of the first sub-layer is greater than or equal to the thickness of the second sub-layer.

6. The display panel according to claim 3, wherein: A first gate insulating layer is provided between the driving gate and the driving active portion, and a second gate insulating layer is provided between the switch gate and the switch active portion. The dielectric constant of the first gate insulating layer is smaller than the dielectric constant of the second gate insulating layer.

7. The display panel according to any one of claims 2 to 6, characterized in that: The display panel includes: substrate; an active layer disposed on one side of the substrate, the active layer comprising a driving active portion of the driving transistor and a switching active portion of the switching transistor; a gate layer, provided on a side of the active layer away from the substrate, the gate layer comprising a driving gate of the driving transistor and a switching gate of the switching transistor; a source-drain electrode layer, disposed on a side of the gate away from the substrate, the source-drain electrode layer including a driving source electrode of the driving transistor; a conductive layer, disposed on a side of the active layer close to the substrate, the conductive layer comprising a first conductive portion corresponding to the driving transistor and a second conductive portion corresponding to the switching transistor; The driving source is connected to the first conductive part, and the switch gate receives the same input signal as the second conductive part.

8. The display panel according to claim 7, wherein: The driving active portion and the switching active portion are both oxide semiconductors.

9. The display panel according to claim 7, wherein: The display panel includes a capacitor arranged on one side of the substrate, and the capacitor includes a stacked first electrode plate and a second electrode plate; The first electrode plate and the driving gate are arranged on the same layer, and the second electrode plate and the switch gate are arranged on the same layer.

10. A display terminal, characterized in that: The display panel comprises the display panel according to any one of claims 1 to 9.

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