Display Panel Pixel Island Shielding for TFT Threshold Stability
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Solution Overview
Problem
The stability of the light emission effect in display panels is compromised due to light-induced threshold drift in the thin-film transistors of the pixel circuit, leading to reduced lifetime.
Innovation Solution
Incorporation of light-blocking structures, including reflective and/or light-absorbing structures on the sidewalls of pixel circuit islands, to prevent light from affecting the semiconductor layer of the transistors, combined with insulating layer modifications to enhance light transmission and electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the thin-film transistor is continuously irradiated by light to drive the light-emitting element, then the light emission function is achieved, but the threshold voltage drifts and the lifetime is reduced
Solution Approach 1:
The pixel circuit island is divided into distinct functional regions: a light-emitting region containing the light-emitting element, and a circuit region containing the thin-film transistor. This spatial segmentation allows the light-emitting element to receive light for operation while the transistor is protected from direct light exposure through the insulating layer structure.
Solution Approach 2:
An insulating layer is introduced as an intermediary between the light-emitting element and the thin-film transistor. This insulating layer selectively transmits light to the light-emitting element while blocking harmful light from reaching the transistor's semiconductor layer, thus protecting the transistor from light-induced threshold voltage drift.
2Productivity
If the insulating layer is modified to enhance light transmission, then the light emission efficiency is improved, but the protection against light interference may be reduced
Solution Approach 1:
The insulating layer is designed with spatially varying optical properties: in the light-emitting region, the insulating layer has high light transmission to enable efficient light emission, while in the circuit region, the insulating layer has light-blocking properties to protect the transistor. This local differentiation of optical characteristics resolves the contradiction between light transmission and light protection.
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
Enhances the stability of the pixel circuit performance by shielding the transistors from light interference, maintaining consistent light emission and improving the display panel's light transmission rate.
Implementation Method 1
light-blocking structures including at least one of a reflective structure or a light-absorbing structure
Implementation Method 2
light-blocking structures including at least one of a reflective structure or a light-absorbing structure
Implementation Method 3
An active layer of the thin-film transistor is usually made of a semiconductor material having a photoelectric effect
Data Source
AI summary
Provided are a display panel and a display device. In an embodiment, the display panel includes: a substrate; pixel circuit islands provided at a side of the substrate, one of the pixel circuit islands includes at least one pixel circuit; light-emitting elements provided at a side of the pixel circuit islands away from the substrate and respectively electrically connected to the pixel circuits of the pixel circuit islands; and light-blocking structures including at least one of a reflective structure or a light-absorbing structure. In an embodiment, the light-blocking structures include first light-blocking structures, each of which is provided on at least one sidewall of one pixel circuit island of the pixel circuit islands. In an embodiment, the first light-blocking structure prevents light out of the pixel circuit island from entering the pixel circuit island through the sidewall of the pixel circuit island.