Pixel Driving TFT With Dual Work-Function Sub-Gates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity of forming pixel driving circuits in each pixel area of display apparatuses leads to deteriorated process efficiency and image quality due to differences in the electrical characteristics of the pixel driving circuits.
Innovation Solution
A display apparatus with a pixel driving circuit that includes a thin film transistor with a gate comprising a first sub-gate and a second sub-gate, where the second sub-gate has a higher work-function than the first sub-gate, and a semiconductor pattern with parallel sub-channels to improve the driving current and reliability of the pixel driving circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a pixel driving circuit is formed in each pixel area with a single gate structure, then the process is simpler, but the driving current is insufficient and image quality deteriorates
Solution Approach 1:
The gate electrode is divided into multiple sub-gates (first sub-gate, second sub-gate, third sub-gate) with different work functions. Each sub-gate independently controls a corresponding sub-channel region, allowing differentiated electrical characteristics across the channel to enhance driving current while maintaining a planar structure that simplifies manufacturing.
Solution Approach 2:
Different regions of the gate electrode are assigned different work functions (first sub-gate with lower work function, second sub-gate with intermediate work function, third sub-gate with higher work function) to create localized electrical characteristics. This enables each sub-channel region to have optimized charge carrier properties, improving overall transistor performance and driving current without increasing structural complexity.
2Power
If the channel region length is reduced to increase driving current, then the driving current increases, but the transistor control capability deteriorates
Solution Approach 1:
The channel is segmented into multiple sub-channel regions (first, second, third sub-channels) with different gate control characteristics. This segmentation allows the effective channel length to be maintained for control capability while the differentiated work functions enhance the driving current through improved charge carrier injection and transport in each region.
Solution Approach 2:
The work function parameter of the gate electrode is varied across different sub-gates to optimize the electrical characteristics of each sub-channel region. By changing the work function parameter rather than the physical dimensions, the driving current is enhanced while the channel length and transistor control capability are preserved.
3Reliability
If different thin film transistors are used for driving and switching functions, then the electrical characteristics are optimized, but the manufacturing process becomes complicated
Solution Approach 1:
The gate electrode is segmented into multiple sub-gates with different work functions within a single thin film transistor structure. This segmentation enables the transistor to exhibit different electrical characteristics in different regions, allowing it to perform both driving and switching functions with optimized characteristics, while maintaining a unified structure that simplifies the manufacturing process.
Solution Approach 2:
A single thin film transistor with a multi-sub-gate structure is designed to perform multiple functions (driving and switching) that traditionally required different transistor types. The different sub-gate work functions enable the same transistor structure to exhibit diverse electrical characteristics, reducing process complexity while maintaining optimized performance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances the reliability and efficiency of the pixel driving circuit by increasing the driving current without reducing the length of the channel region, thereby improving image quality and process efficiency.
Implementation Method 1
the second sub-gate overlapping the second sub-channel has a work-function greater than the first sub-gate overlapping the first sub-channel
Implementation Method 2
An electric field applied to the first sub-channel by the first sub-gate is different from an electric field applied to the second sub-channel by the second sub-gate
Data Source
AI summary
A display apparatus includes a pixel driving circuit including a thin film transistor; and a light-emitting device electrically connected to the pixel driving circuit, wherein a gate of the thin film transistor includes a first sub-gate and a second sub-gate electrically connected to the first sub-gate, wherein the thin film transistor has a semiconductor pattern that includes a first sub-channel and a second sub-channel, which are disposed parallel to each other between a drain region and a source region, and wherein the second sub-gate overlapping the second sub-channel has a work-function greater than the first sub-gate overlapping the first sub-channel, thus increasing a driving current and improving reliability without decreasing a threshold voltage.