Display Panel Photosensor Structure for Low Dark Current Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
It is difficult to integrate ambient photosensitive devices into conventional display panels at a low cost due to the need for external attachment, which increases manufacturing costs.
Innovation Solution
A display panel design that integrates a photosensitive device with a thin-film transistor (TFT) device, featuring a vertical heterojunction structure and a barrier component, allowing for reduced photomask usage and cost by sharing manufacturing processes with existing layers, thereby integrating the photosensitive device into the array substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ambient photosensitive devices are integrated into array substrates using conventional methods, then manufacturing cost is reduced, but device complexity and manufacturing difficulty increase due to the need for additional photomasks and process steps
Solution Approach 1:
The patent merges the photosensitive device structure with the TFT device structure by sharing common layers including the active layer, gate insulating layer, gate electrode, source electrode, drain electrode, and interlayer insulating layer. This integration allows both devices to be manufactured using the same photomasks and process steps, reducing manufacturing cost while avoiding increased device complexity
Solution Approach 2:
The common layers serve dual functions: they form the TFT device for display control and simultaneously form the photosensitive device for ambient light detection. The active layer, gate, source, and drain structures are universally used by both devices, eliminating the need for separate manufacturing processes
2Reliability
If the second lightly-doped part has large contact area with the connector electrode, then electrical connection is improved, but dark current increases reducing sensitivity
Solution Approach 1:
The patent applies local quality by creating different doping regions (heavily-doped, lightly-doped, and intrinsic parts) within the active layer at different locations. The lightly-doped part provides good electrical contact with the connector electrode, while the surrounding heavily-doped and intrinsic parts create a barrier structure that blocks dark current, thus achieving both reliable electrical connection and low dark current
Solution Approach 2:
The barrier component acts as an intermediary structure between the lightly-doped part and the environment. It blocks dark current while allowing the lightly-doped part to maintain good electrical contact with the connector electrode, thus mediating between the conflicting requirements of electrical connection and dark current suppression
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 approach reduces the dark current of the photosensitive device, enhancing sensitivity and allowing for cost-effective integration of ambient light detection functions into display panels, improving their competitiveness and functionality.
Implementation Method 1
a barrier component, the second active pattern comprises a second intrinsic part, a second heavily-doped part, a second lightly-doped part
Implementation Method 2
the first electrode, the second electrode, the connector electrode, and the second active pattern constitute a vertical heterojunction structure
Implementation Method 3
the second active pattern comprises a second intrinsic part, a second heavily-doped part, a second lightly-doped part
Data Source
AI summary
A display panel is disclosed. The display panel includes a photosensitive device. The photosensitive device includes a barrier component and a second active pattern. The second active pattern includes a second lightly-doped part, a second intrinsic part surrounding the second lightly-doped part, and a second heavily-doped part surrounding the second intrinsic part. In a film thickness direction, the barrier component overlaps the second intrinsic part. A dark current of the photosensitive device is reduced by the second intrinsic part, thereby improving sensitivity.