Mixed-Gate TFT Pixel Circuit for High-Resolution Display Stability
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Solution Overview
Problem
Current display technologies face challenges in achieving both high resolution and stability in TFT devices due to the use of same structure type TFTs, which cannot meet the differing stability requirements of switching and driving TFTs in pixel circuits.
Innovation Solution
Implementing a display device with a bottom-gate switching TFT and a novel top-gate driving TFT configuration, where the first gate is positioned below the first active layer and the second gate is positioned above the second active layer, enhancing stability while maintaining high resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If bottom-gate TFT structure is used, then TFT size is reduced and resolution is enhanced, but device stability deteriorates
Solution Approach 1:
The invention divides the TFT devices into two segments: bottom-gate TFTs for switching functions (where size matters) and top-gate TFTs for driving functions (where stability matters). This segmentation allows each TFT type to be optimized for its specific function, resolving the contradiction between resolution and stability.
Solution Approach 2:
Different gate structures are applied to different functional locations within the pixel circuit. Bottom-gate structure is used where size reduction is critical (switching TFT), while top-gate structure is used where stability is critical (driving TFT). This local differentiation resolves the contradiction by matching structure to functional requirements.
2Reliability
If top-gate TFT structure is used, then device stability is improved, but TFT size increases and resolution deteriorates
Solution Approach 1:
The pixel circuit is segmented to use top-gate TFTs only for driving functions where stability is required, while bottom-gate TFTs handle switching functions. This segmentation prevents the stability benefit from being lost to size increase in critical resolution areas.
Solution Approach 2:
Top-gate structure is selectively applied to driving TFTs where stability is the priority, rather than uniformly across all TFTs. This local application maintains stability where needed without compromising overall resolution.
3Device complexity
If same structure type TFT is used for both switching and driving functions, then device complexity is reduced, but inability to meet different stability requirements worsens performance
Solution Approach 1:
The invention segments the TFT population by function: bottom-gate TFTs for switching and top-gate TFTs for driving. This functional segmentation allows each type to meet its specific stability requirements while maintaining overall circuit functionality.
Solution Approach 2:
Different gate structures are assigned to different functional roles within the pixel circuit. Switching TFTs use bottom-gate structure optimized for size, while driving TFTs use top-gate structure optimized for stability, matching structure to local functional requirements.
Data Source
AI summary
A display device and a manufacturing method thereof are provided. The display device includes a substrate, a switching thin film transistor, and a driving thin film transistor. The switching thin film transistor includes a first gate, a first active layer, a first source, and a first drain disposed on the substrate, wherein the first source and the first drain are disposed on a side of the first active layer away from the substrate. The driving thin film transistor includes a second source, a second drain, a second active layer, and a second gate disposed on the substrate, wherein the second active layer is positioned on a side of the second source and the second drain away from the substrate.