Thin film transistor, display panel and display device

Abstract

The present application provides a thin film transistor, a display panel, and a display device. The thin film transistor comprises an active layer. An oxide semiconductor material of the active layer is doped with a first metal element containing a terbium element, so as to increase a heterostructure in the active layer and reduce crystallinity of the active layer, thereby improving the uniformity and stability of the thin film transistor.

Description

Thin-film transistors, display panels and display devices

[0001] This application requires filing with the China National Intellectual Property Administration on January 24, 2025, with application numbers 202510122892.0, 202520173868.5, 202520174122.6, 202520172407.6, 202510122918.1, 202510121539.0, 202510121244.3, 202510122793.2, 202510120882.3, and 202510121566. The priority of Chinese patent applications .8, 202510121440.0, 202510122941.0, 202510122786.2, 202510122898.8, 202510122890.1, 202510122905.4, 202520173722.0, 202510122928.5, 202510121424.1, and 202520172783.5, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of display technology, and more particularly to a thin-film transistor, a display panel, and a display device. Background Technology

[0003] With increasing user demands for high resolution, high definition, fast response, and low power consumption in display panels, oxide semiconductor thin film transistors (OS TFTs) are being increasingly used in liquid crystal displays (LCDs) and organic light-emitting diode (OLED) display panels due to their high carrier mobility, low off-state leakage current, and high uniformity.

[0004] Currently, with the increasing demand for larger sizes and higher resolutions in the display industry, higher requirements are being placed on the mobility and stability of oxide semiconductors. For large-size display panels, factors such as process instability and equipment parameter instability in the film deposition process lead to significant differences in the performance parameters of oxide thin-film transistors, ultimately affecting the uniformity and stability of oxide semiconductor thin-film transistors in large-size display panels.

[0005] Therefore, it is necessary to provide a thin-film transistor, a display panel, and a display device to improve this deficiency. Summary of the Invention

[0006] Embodiments of this application provide a thin-film transistor, a display panel, and a display device that can improve the uniformity and stability of oxide thin-film transistors.

[0007] To achieve the above objectives, according to a first aspect of this application, a thin-film transistor is provided, comprising:

[0008] Active layer;

[0009] A gate is disposed on one side of the active layer;

[0010] The active layer is made of an oxide semiconductor material and a first metal element doped in the oxide semiconductor material, wherein the first metal element is terbium.

[0011] According to a second aspect of this application, a display panel is provided, including thin-film transistors as described above.

[0012] According to a third aspect of this application, a display device is provided, including a display panel as described above. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0015] Figure 1 is a schematic diagram of the structure of a first type of display panel provided in an embodiment of this application;

[0016] Figure 2 is a schematic diagram of the structure of a second type of display panel provided in an embodiment of this application;

[0017] Figure 3 is a schematic diagram of a display device provided in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1. Display panel; 11. Substrate; 12. Thin film transistor; 121. Active layer; 122. Gate; 123. Source; 124. Drain; 13. Gate insulating layer; 14. Passivation layer; 15. Light-shielding layer; 16. Barrier layer; 17. Interlayer dielectric layer;

[0020] 10. Display device. Embodiments of the present invention

[0021] Embodiments of this application provide a thin-film transistor, a display panel, and a display device that can improve the uniformity and stability of oxide thin-film transistors.

[0022] To achieve the above objectives, according to a first aspect of this application, a thin-film transistor is provided, comprising:

[0023] Active layer;

[0024] A gate is disposed on one side of the active layer;

[0025] The active layer is made of an oxide semiconductor material and a first metal element doped in the oxide semiconductor material, wherein the first metal element is terbium.

[0026] Optionally, the oxide semiconductor material is further doped with a second metal element, wherein the second metal element is in a positive tetravalent state;

[0027] Optionally, the atomic percentage of the first metal element is greater than 0 and less than or equal to 3%, and the atomic percentage of the second metal element is greater than 0 and less than or equal to 20%.

[0028] Optionally, the second metallic element includes tin.

[0029] Optionally, the oxide semiconductor material includes indium and gallium.

[0030] Wherein, the atomic percentage of indium is greater than or equal to 60% and less than or equal to 90%, and the atomic percentage of gallium is greater than or equal to 0 and less than or equal to 20%.

[0031] Optionally, the carrier concentration of the active layer is greater than or equal to 10. 19 cm -3 and less than or equal to 10 20 cm -3 .

[0032] Optionally, the bandgap of the active layer is greater than or equal to 3 eV and less than or equal to 3.8 eV.

[0033] Optionally, the active layer is configured in a crystalline state.

[0034] Optionally, the active layer is configured in an amorphous state.

[0035] Optionally, the thin-film transistor further includes a source and a drain, the source and the drain being connected to the active layer, respectively;

[0036] When the gate is configured to have no gate voltage applied, the current between the source and the drain is configured to be less than or equal to 10. -10 A.

[0037] Optionally, the gate is disposed on the side of the active layer away from the source, or the gate is disposed on the side of the active layer close to the source.

[0038] According to a second aspect of this application, a display panel is provided, including thin-film transistors as described above.

[0039] According to a third aspect of this application, a display device is provided, including a display panel as described above.

[0040] In the thin-film transistor of this application embodiment, by doping the oxide semiconductor material of the active layer of the thin-film transistor with a first metal element including terbium, the heterostructure in the active layer is increased and the crystallinity of the active layer is reduced, thereby improving the uniformity and stability of the thin-film transistor.

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0042] An embodiment of this application provides a thin-film transistor, which includes an active layer and a gate. The gate is disposed on one side of the active layer. The active layer is made of an oxide semiconductor material and a first metal element doped in the oxide semiconductor material. The first metal element includes terbium.

[0043] In the embodiments of this application, by doping the oxide semiconductor material of the active layer of the thin-film transistor with a first metal element including terbium, the heterostructure in the active layer is increased and the crystallinity of the active layer is reduced, thereby improving the uniformity and stability of the thin-film transistor.

[0044] Please refer to Figure 1, which is a schematic diagram of the structure of a first type of display panel provided in an embodiment of this application. A thin-film transistor 12 is applied to the display panel 1, which includes a substrate 11 and the thin-film transistor 12, which is disposed on the substrate 11. The thin-film transistor 12 includes an active layer 121, the material of which includes an oxide semiconductor material and a first metal element doped in the oxide semiconductor material, the first metal element including terbium (Tb).

[0045] In the embodiments of this application, by doping the oxide semiconductor material of the active layer 121 of the thin-film transistor 12 with a first metal element containing terbium, the heterostructure in the active layer 121 is increased, the crystallinity of the active layer 121 is reduced, thereby improving the uniformity and stability of the thin-film transistor 12. In practical applications, other metal elements that have the same effect as terbium can also be used as the first metal element for doping.

[0046] In some embodiments, referring to FIG1, the oxide semiconductor material of the active layer 121 is further doped with a second metal element, including tin (Sn). Tin can provide charge carriers and passivate oxygen-related defects, while terbium can provide photogenerated carrier recombination centers, thereby improving photostability. By simultaneously doping the active layer 121 with tin and terbium, the heterostructure in the active layer 121 can be increased, and the crystallinity of the active layer 121 can be reduced, thereby improving the uniformity and stability of the thin-film transistor 12. In practical applications, other metal elements with the same effect as tin can also be doped as second metal elements.

[0047] In some embodiments, referring to FIG1, the atomic percentage of the second metal element in the active layer 121 is greater than 0 and less than or equal to 20%, and the atomic percentage of the first metal element is greater than 0 and less than or equal to 3%. For example, the atomic percentage of tin in the active layer 121 is 20%, and the atomic percentage of terbium is 1%; or, the atomic percentage of tin in the active layer 121 is 10%, and the atomic percentage of terbium is 2%; or, the atomic percentage of tin in the active layer 121 is 1%, and the atomic percentage of terbium is 3%.

[0048] In some embodiments, the active layer 121 is doped with terbium but not with tin. That is, the atomic percentage of tin is 0, and the atomic percentage of terbium is greater than or equal to 0 and less than or equal to 3%. This can also increase the heterostructure in the active layer 121, reduce the crystallinity of the active layer 121, and thereby improve the uniformity and stability of the thin-film transistor 12.

[0049] In some embodiments, the oxide semiconductor material includes indium (In) and gallium (Ga), wherein the atomic percentage of indium is greater than or equal to 60% and less than or equal to 90%, and the atomic percentage of gallium is greater than or equal to 0 and less than or equal to 20%.

[0050] It should be noted that in this embodiment, indium oxide is used as the main material of the active layer 121, with a relatively high proportion, resulting in a large carrier concentration and thus high mobility. If the atomic percentage of indium in the active layer 121 is less than 60%, the mobility of the active layer 121 will be low and will not meet the requirements. Furthermore, the atomic percentage of indium is related to the crystallization state of the active layer. When the atomic percentage of indium is less than 80%, the active layer 121 is in a crystalline state; when the atomic percentage of indium is greater than 80%, the active layer 121 is in an amorphous state. Gallium has a relatively low proportion; gallium can act as a carrier suppressor, thereby reducing oxygen vacancies in the active layer 121 and improving its stability.

[0051] In some embodiments, the active layer 121 contains indium, and gallium is completely replaced by terbium and / or tin. That is, the oxide semiconductor material is indium oxide, and the indium oxide is used as the main material of the active layer 121. By doping the indium oxide with terbium, or by doping the indium oxide with both tin and terbium, the heterostructure in the active layer 121 can be increased, the crystallinity of the active layer 121 can be reduced, thereby improving the uniformity and stability of the thin film transistor 12.

[0052] In some embodiments, the active layer 121 contains indium and gallium, meaning the active layer 121 is made of indium gallium oxide (IGNOW) doped with terbium, or simultaneously doped with tin and terbium. Gallium acts as a carrier suppressor, thereby reducing oxygen vacancies in the active layer 121 and improving its stability. By doping terbium into IGNOW, or simultaneously doping with tin and terbium, the heterostructure in the active layer 121 can be increased, reducing its crystallinity and thus improving the uniformity and stability of the thin-film transistor 12.

[0053] In some embodiments, the carrier concentration of the active layer 121 is greater than or equal to 10. 19 cm -3 and less than or equal to 10 20 cm -3 For example, the carrier concentration of active layer 121 is 10. 19 cm -3 Or 10 20 cm -3 It should be noted that the carrier concentration and mobility of the active layer 121 are positively correlated. This can be achieved by limiting the carrier concentration of the active layer 121 to 10... 19 cm -3 and less than or equal to 10 20 cm -3This not only allows the active layer 121 to have a high mobility, but also maintains the switching characteristics of the thin-film transistor 12, preventing the thin-film transistor 12 from becoming difficult to turn off.

[0054] In some embodiments, the bandgap of the active layer 121 is greater than or equal to 3 eV and less than or equal to 3.8 eV. For example, the bandgap of the active layer 121 is 3.2 eV, 3.4 eV, 3.6 eV, or 3.8 eV, etc.

[0055] It should be noted that if the bandgap of the active layer is too low, the optical stability of the active layer will be poor; if the bandgap of the active layer is too high, the mobility of the active layer will be degraded. The embodiments of this application limit the bandgap of the active layer 121 to between 3 eV and 3.8 eV by doping the active layer with only terbium or by doping it with both terbium and tin, thereby improving the stability of the active layer while achieving high mobility.

[0056] In some implementations, the second metal element is in a tetravalent state. It should be noted that tetravalent tin ions act as donor dopant, replacing cations in the active layer 121. Each tetravalent tin ion provides an additional free electron, thereby increasing the number of electrons and forming N-type doping, which can improve the carrier concentration in the active layer 121. The tetravalent tin ions not only reduce lattice defects in the active layer 121 and lower electron scattering, but also reduce impurity scattering, thus further improving the mobility of the active layer 121.

[0057] In some implementations, the active layer 121 is configured in a crystalline state. By doping the active layer 121 with tin and terbium, the heterostructure in the active layer 121 is increased, the crystallinity of the active layer is reduced, and the uniformity and stability of the thin film transistor can be improved.

[0058] In some implementations, the active layer 121 is configured in an amorphous state, which is an amorphous state. The mobility of the active layer 121 in the amorphous state increases with the increase of carrier concentration. By increasing the carrier concentration of the active layer 121, the mobility of the active layer 121 can be improved.

[0059] In some embodiments, referring to FIG1, the thin-film transistor 12 includes a gate 122, a source 123, and a drain 124. Along the thickness direction of the gate 122, the gate 122 is aligned with the active layer 121. The source 123 and drain 124 are respectively connected to the active layer 121. When the gate 122 is configured to have no gate voltage applied, the current between the source 123 and the drain 124 is configured to be less than or equal to 10. -10 A. By providing a voltage of less than or equal to 10 between the source 123 and the drain 124 when no gate voltage is applied. -10The current of A can reduce the off-state current of the thin-film transistor 12, thereby reducing the power consumption of the thin-film transistor 12.

[0060] In some embodiments, please refer to FIG1, the thin film transistor 12 has a bottom gate structure, and the gate 122 is disposed on the side of the active layer 121 near the substrate 11.

[0061] In some embodiments, referring to FIG1, the display panel 1 further includes a gate insulating layer 13 and a passivation layer 14. The gate insulating layer 13 is disposed on the substrate 11 and the gate 122. The active layer 121 is disposed on the surface of the gate insulating layer 13 away from the substrate 11. The source 123 and the drain 124 are disposed on the active layer 121 and overlap with the opposite ends of the active layer 121, respectively. The passivation layer 14 is disposed on the source and drain 124 and covers the active layer 121 and the gate insulating layer 13.

[0062] In some embodiments, please refer to FIG2, which is a schematic diagram of the structure of a second type of display panel provided in the embodiments of this application. Its structure is roughly the same as that of the thin film transistor in the first type of display panel shown in FIG1. ​​The difference is that the thin film transistor 12 in the display panel shown in FIG2 is a top gate structure, and the gate 122 is disposed on the side of the active layer 121 away from the substrate 11. The display panel 1 also includes a light-shielding layer 15, a barrier layer 16, a gate insulating layer 13, an interlayer dielectric layer 17, and a passivation layer 14. The light-shielding layer 15 is disposed on the substrate 11, the barrier layer 16 is disposed on the substrate 11 and the light-shielding layer 15, the active layer 121 is disposed on the surface of the barrier layer 16 away from the substrate 11, the gate insulating layer 13 is disposed on the surface of the active layer 121 away from the substrate 11, the gate 122 is disposed on the surface of the gate insulating layer 13 away from the active layer 121, the interlayer dielectric layer 17 is disposed on the gate 122 and the active layer 121, the source 123 and the drain 124 are disposed on the interlayer dielectric layer 17, and the source 123 and the drain 124 are respectively connected to the active layer 121 through vias on the interlayer dielectric layer 17. The passivation layer 14 is disposed on the source 123, the drain 124, and the interlayer dielectric layer 17.

[0063] As can be seen from Figures 1 and 2, the thin-film transistors provided in the embodiments of this application can be top-gate structures or bottom-gate structures. The thin-film transistors can also be back-channel etched thin-film transistors or top-gate self-aligned thin-film transistors. By doping terbium or simultaneously doping terbium and tin in the active layer of the above-mentioned thin-film transistors, the heterostructure in the active layer can be increased, the crystallinity of the active layer can be reduced, thereby improving the uniformity and stability of the thin-film transistors.

[0064] Based on the thin-film transistors provided in the above embodiments of this application, embodiments of this application also provide a display panel. Please refer to FIG2. The display panel includes the thin-film transistors provided in any of the above embodiments. The display device provided in the embodiments of this application can achieve the same technical effects as the thin-film transistors provided in any of the above embodiments, which will not be elaborated here.

[0065] In some embodiments, the display panel 1 is a liquid crystal display panel, which includes an array substrate, a counter substrate, and a liquid crystal layer (not shown in the figure). The counter substrate is disposed opposite to the array substrate, and the liquid crystal layer is disposed between the array substrate and the counter substrate. The array substrate includes thin-film transistors. When the color filter layer is disposed on one side of the counter substrate, the counter substrate can also be regarded as a color filter substrate.

[0066] In some embodiments, the display panel is an organic light-emitting diode (OLED) display panel or a micro-LED display panel. Specifically, the display panel may include an array substrate and a light-emitting device layer. The array substrate includes thin-film transistors, and the light-emitting device layer is disposed on the array substrate. The light-emitting device layer has multiple light-emitting devices, which may be organic light-emitting diodes or micro-LED chips.

[0067] Based on the display panel provided in the above embodiments of this application, embodiments of this application also provide a display device. Please refer to FIG3, which is a schematic diagram of the display device provided in the embodiments of this application. The display device 10 includes a display panel 1, which can be the display panel provided in any of the above embodiments. The display device provided in the embodiments of this application can achieve the same technical effects as the display panel provided in any of the above embodiments, and will not be described in detail here.

[0068] The beneficial effects of the embodiments of this application are as follows: The embodiments of this application provide a thin film transistor, a display panel, and a display device. The thin film transistor includes an active layer and a gate. By doping the oxide semiconductor material of the active layer with a first metal element including terbium, the heterostructure in the active layer is increased and the crystallinity of the active layer is reduced, thereby improving the uniformity and stability of the thin film transistor.

[0069] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying 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, "multiple" means two or more, unless otherwise explicitly specified.

[0070] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0071] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0072] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A thin-film transistor, comprising: Active layer; A gate is disposed on one side of the active layer; The active layer comprises an oxide semiconductor material and a first metal element doped in the oxide semiconductor material, wherein the first metal element comprises terbium.

2. The thin-film transistor of claim 1, wherein, The oxide semiconductor material is also doped with a second metal element, which is in a positive tetravalent state.

3. The thin-film transistor of claim 2, wherein, The atomic percentage of the first metal element is greater than 0 and less than or equal to 3%, and the atomic percentage of the second metal element is greater than 0 and less than or equal to 20%.

4. The thin-film transistor as claimed in claim 2 or 3, wherein, The second metallic element includes tin.

5. The thin-film transistor of claim 1, wherein, The oxide semiconductor material includes indium and gallium.

6. The thin-film transistor of claim 5, wherein, The atomic percentage of indium is greater than or equal to 60% and less than or equal to 90%, and the atomic percentage of gallium is greater than or equal to 0 and less than or equal to 20%.

7. The thin-film transistor of claim 1, wherein, The carrier concentration of the active layer is greater than or equal to 10. 19 cm -3 and less than or equal to 10 20 cm -3 .

8. The thin-film transistor of claim 1, wherein, The bandgap of the active layer is greater than or equal to 3 eV and less than or equal to 3.8 eV.

9. The thin-film transistor of claim 1, wherein, The active layer is in a crystalline state.

10. The thin-film transistor of claim 1, wherein, The active layer is in an amorphous state.

11. The thin-film transistor of claim 1, wherein, The thin-film transistor further includes a source and a drain, the source and the drain being connected to the active layer respectively; When the gate is configured to have no gate voltage applied, the current between the source and the drain is configured to be less than or equal to 10. -10 A.

12. The thin-film transistor of claim 11, wherein, The gate is disposed on the side of the active layer away from the source electrode, or the gate is disposed on the side of the active layer closer to the source electrode.

13. A display panel including thin-film transistors, the thin-film transistors comprising: Active layer; A gate is disposed on one side of the active layer; The active layer comprises an oxide semiconductor material and a first metal element doped in the oxide semiconductor material, wherein the first metal element comprises terbium.

14. The display panel as claimed in claim 13, wherein, The oxide semiconductor material is also doped with a second metal element, which is in a positive tetravalent state.

15. The display panel as claimed in claim 14, wherein, The atomic percentage of the first metal element is greater than 0 and less than or equal to 3%, and the atomic percentage of the second metal element is greater than 0 and less than or equal to 20%.

16. The display panel as claimed in claim 14 or 15, wherein, The second metallic element includes tin.

17. The display panel as claimed in claim 13, wherein, The oxide semiconductor material includes indium and gallium.

18. The display panel as claimed in claim 17, wherein, The atomic percentage of indium is greater than or equal to 60% and less than or equal to 90%, and the atomic percentage of gallium is greater than or equal to 0 and less than or equal to 20%.

19. The display panel as claimed in claim 13, wherein, The carrier concentration of the active layer is greater than or equal to 10. 19 cm -3 and less than or equal to 10 20 cm -3 .

20. A display device comprising a display panel as described in claims 13 to 19.

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