Display Pixel Driving Transistor Offset Structure for Leakage Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices face issues with leakage currents from driving transistors unintentionally setting light-emitting elements into a light emission state, leading to unwanted illumination.
Innovation Solution
Incorporating a driving transistor with an offset structure featuring an insulator between the gate and the semiconductor region forming a source or drain, which reduces the electric field and minimizes leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional driving transistor structure is used, then the device complexity is low, but leakage current increases causing unintended light emission
Solution Approach 1:
The driving transistor is segmented into multiple regions including a first semiconductor region, second semiconductor region, third semiconductor region, and fourth semiconductor region with different conductivity types. This segmentation creates distinct functional zones that control electric field distribution to suppress leakage current while maintaining manageable structural complexity.
Solution Approach 2:
Different semiconductor regions are assigned different conductivity types (first conductivity type and second conductivity type) to create local quality variations. The offset structure is implemented locally at specific positions where leakage current suppression is most critical, allowing targeted improvement without uniformly increasing overall device complexity.
2Manufacturing precision
If the electric field in the semiconductor region is increased to improve current control, then the current control precision improves, but leakage current increases causing unintended light emission
Solution Approach 1:
The offset structure creates equipotential regions by introducing semiconductor regions with opposite conductivity types adjacent to the gate. This reduces the electric field strength in critical areas, preventing excessive current control that would generate harmful leakage currents while maintaining necessary current precision through the structured conductivity variations.
Solution Approach 2:
The offset structure acts as an intermediary element between the gate and the main current path. It mediates the electric field distribution, allowing precise current control to be achieved without directly increasing the electric field strength in regions where it would cause leakage current and unintended light emission.
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
This configuration effectively suppresses leakage currents, preventing unintended light emission and enabling high-quality black display in light-emitting devices.
Implementation Method 1
If an electric field in a semiconductor region forming a source or a drain of the driving transistor is large, for example, a leakage current flowing between the source and the drain is accelerated and increased by the electric field
Data Source
AI summary
A light-emitting device includes a plurality of pixels arranged in a substrate. Each pixel includes a light-emitting element, a driving transistor configured to supply a current to the light-emitting element, and a write transistor configured to supply a signal voltage to a gate of the driving transistor. The driving transistor has an offset structure that includes an insulator between the gate and a semiconductor region forming one of a source and a drain of the driving transistor in an orthogonal projection to a main surface of the substrate.