CN-122028502-A - Transistor and display device including the same

Abstract

A display device includes a substrate including a first region including a first subpixel and a transmissive portion and a second region including a second subpixel. The first transistor in the first region includes an oxide semiconductor active layer, a gate electrode, and first and second source-drain electrodes. The second transistor disposed in the first region includes an oxide semiconductor active layer including a first active layer and a second active layer, a gate electrode, and first and second source-drain electrodes. The light emitting element is disposed in the first region. The third transistor is connected between the second transistor and the light emitting element and includes an oxide semiconductor active layer including first and second active layers, a gate electrode, and first and second source-drain electrodes. The second active layer of the third transistor has a carrier mobility higher than that of the first active layer of the third transistor.

Inventors

• REN SHUYAN

Assignees

• 乐金显示有限公司

Dates

Publication Date

20260512

Application Date

20250930

Priority Date

20241112

Claims (20)

1. 1. A transistor, comprising: An active layer including an oxide semiconductor material, the active layer including a first active layer and a second active layer in contact with the first active layer, the second active layer having a carrier mobility higher than a carrier mobility of the first active layer; A gate electrode overlapping at least a portion of the first active layer and at least a portion of the second active layer of the active layer to form a channel region; A first source-drain electrode insulated from the gate electrode and connected to another portion of the second active layer not overlapping the gate electrode, and And a second source-drain electrode insulated from the gate electrode and connected to another portion of the first active layer not overlapping the gate electrode.
2. 2. The transistor of claim 1, wherein the first active layer and the second active layer are both disposed on an insulating layer and directly contact an upper surface of the insulating layer in a region overlapping the gate electrode.
3. 3. The transistor of claim 1, wherein the channel region comprises: a first channel region in which the gate electrode and the first active layer overlap each other, and And a second channel region in which the gate electrode and the second active layer overlap each other.
4. 4. The transistor of claim 3, wherein a length of the second channel region is greater than a length of the first channel region.
5. 5. The transistor of claim 3, wherein at least a portion of the first channel region does not overlap with at least a portion of the second active layer.
6. 6. The transistor of claim 1, wherein The second active layer overlaps the gate electrode by a length greater than the first active layer overlaps the gate electrode.
7. 7. The transistor of claim 1, wherein at least a portion of the first active layer extends up to a portion of the upper surface of the second active layer to cover at least the portion of the upper surface of the second active layer.
8. 8. The transistor of claim 1, wherein at least a portion of the second active layer extends up to a portion of the upper surface of the first active layer to cover at least the portion of the upper surface of the first active layer.
9. 9. The transistor of claim 1, wherein The second active layer includes a second lower active layer disposed under the first active layer, and a second upper active layer disposed on an upper surface of the first active layer, an The length of the second upper active layer of the second active layer is smaller than the length of the second lower active layer of the second active layer.
10. 10. The transistor of claim 1, wherein The first active layer includes a first lower active layer disposed under the second active layer, and a first upper active layer disposed on an upper surface of the second active layer, and The length of the first upper active layer of the first active layer is smaller than the length of the first lower active layer of the first active layer.
11. 11. The transistor of claim 1, further comprising: And a lower metal disposed under the active layer and electrically connected with the first source-drain electrode.
12. 12. The transistor of claim 1, wherein the active layer comprises a structure in which the first active layer and the second active layer are stacked at a central portion of the channel region.
13. 13. The transistor of claim 1, wherein the active layer comprises a structure in which the first active layer and the second active layer are alternately stacked at a central portion of the channel region.
14. 14. The transistor of claim 13, wherein the first active layer comprises a first lower active layer and a first upper active layer, wherein the second active layer is interposed between the first lower active layer and the first upper active layer of the first active layer.
15. 15. The transistor of claim 13, wherein the second active layer comprises a second lower active layer and a second upper active layer, wherein the first active layer is interposed between the second lower active layer and the second upper active layer of the second active layer.
16. 16. A display device, comprising: a substrate including a first region including a plurality of first sub-pixels and a transmissive portion, and a second region including a plurality of second sub-pixels and not including a transmissive portion; a light emitting element at the first region, and A transistor connected to the light emitting element at the first region having the transmissive portion, Wherein the transistor at the first region is the transistor according to claim 1.
17. 17. A display device, comprising: A substrate including a first region including a plurality of first sub-pixels and a transmissive part and a second region including a plurality of second sub-pixels; A first transistor disposed in the first region having the transmissive portion, the first transistor including an active layer including an oxide semiconductor material, a gate electrode, a first source-drain electrode, and a second source-drain electrode; A second transistor disposed in the first region having the transmissive portion, the second transistor including an active layer, a gate electrode, a first source-drain electrode, and a second source-drain electrode, the active layer including a first active layer and a second active layer, the first active layer and the second active layer each including an oxide semiconductor material; A light emitting element provided in the first region having the transmissive portion, and A third transistor electrically connected between the second transistor and the light emitting element, the third transistor including an active layer, a gate electrode, a first source-drain electrode, and a second source-drain electrode, the active layer including a first active layer and a second active layer, the first active layer and the second active layer each including an oxide semiconductor material, Wherein the second active layer of the third transistor has a carrier mobility higher than that of the first active layer of the third transistor.
18. 18. The display device according to claim 17, wherein The second source-drain electrode of the third transistor is connected to the first active layer of the third transistor, The first active layer of the third transistor has a carrier mobility lower than that of the second active layer of the third transistor, and The second source-drain electrode of the third transistor is electrically connected to the first electrode of the light emitting element.
19. 19. The display device according to claim 17, wherein a current flow direction during the operation of the third transistor proceeds toward the first electrode of the light emitting element in order of the first source-drain electrode of the third transistor, the second active layer of the third transistor, the first active layer of the third transistor, and the second source-drain electrode of the third transistor, the first active layer of the third transistor having a mobility lower than that of the second active layer of the third transistor.
20. 20. The display device according to claim 17, wherein The first transistor is a switching transistor, The second transistor is a driving transistor, and The third transistor is a light emitting transistor.

Description

Transistor and display device including the same Cross-reference to related applications The present application claims priority from korean patent application No. 10-2024-0160311, filed on 11/12 of 2024, which is incorporated herein by reference in its entirety as if fully set forth herein. Technical Field The present disclosure relates to a transistor and a display device including the same. Background Display devices configured to display images in TVs, monitors, smart phones, tablet computers, notebook computers, and the like use various systems and forms. Among display devices, a light emitting display device having a light emitting element in a display panel without a separate light source is considered as a competing application of compact and clear color representation. Display devices typically employ transistors to perform a variety of different functions. For example, a display device may include an active area having a plurality of pixels to realize an image, the active area being provided with transistors configured to control pixel operations on a pixel basis. In contrast, in an inactive area surrounding a plurality of pixels, the display device may include transistors for other functions, such as providing data and control signals to the plurality of pixels. However, transistors for different functions may require different characteristics, and thus, structural differences between various transistors are necessary. On the other hand, it is advantageous to form all the various transistors by the same process to reduce the processing steps. Accordingly, a display device having a transistor which has a structural difference but is manufactured by the same process is required. Disclosure of Invention Accordingly, the present disclosure is directed to a transistor and a display device including the same that substantially obviate one or more problems due to limitations and disadvantages of the related art. An object of the present disclosure is to provide a transistor capable of reducing occurrence of hot carrier stress phenomenon and a display device including the same. Another object of the present disclosure is to provide a transistor capable of increasing an area of a transmission portion of a display region and improving transmittance, and a display device including the transistor. It is still another object of various embodiments according to the present disclosure to provide a transistor capable of enhancing image quality while providing high brightness, and a display device including the transistor. It is a further object of various embodiments according to the present disclosure to set the S factor and the on current value differently according to the function of the transistor. Further, it is another object to provide a transistor which is advantageous for gray scale reproduction, stable, and finely controllable, and a display device including the same. In addition, another object is to achieve environmental/social/regulatory (ESG) goals by improving the reliability of transistors and reducing the power consumption of transistors. The objects of the present disclosure are not limited to the above objects, and other objects of the present disclosure that have not been described will be more clearly understood by those skilled in the art from the following description. To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a transistor includes an active layer including a first active layer including an oxide semiconductor material and a second active layer having carrier mobility higher than that of the first active layer, a gate electrode disposed to overlap the active layer to form a channel region of the active layer, a first source-drain electrode insulated from the gate electrode and connected to the second active layer, and a second source-drain electrode insulated from the gate electrode and connected to the first active layer. A transistor according to an embodiment of the present disclosure may include an active layer including a region where a second active layer and a gate electrode do not overlap. The first active layer and the second source-drain electrode may be connected to each other at a region where the second active layer and the gate electrode do not overlap each other. The second active layer and the first source-drain electrode may be connected to each other at a region where the first active layer and the gate electrode do not overlap each other. The channel region may include a first channel region in which the gate electrode and the first active layer overlap each other, and a second channel region in which the gate electrode and the second active layer overlap each other. The length of the second channel region may be greater than the length of the first channel region. In other embodiments, the transistor may include at least a portion of the first channel region that does not