Photodiode-TFT Layout With Integrated Light Blocking
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Solution Overview
Problem
Existing detection devices require additional manufacturing processes to implement light-blocking layers for thin-film transistors, increasing complexity and cost.
Innovation Solution
A detection device design that incorporates a thin-film transistor with a semiconductor layer between a light-blocking layer and a photodiode, and an electrode layer between the semiconductor layer and the photodiode, reducing the number of manufacturing processes needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If light-blocking layers are provided on both sides of the semiconductor with the semiconductor interposed therebetween, then light blocking to the thin-film transistor is improved, but the number of manufacturing processes increases
Solution Approach 1:
The patent extracts the light-blocking function from a separate layer and integrates it into the electrode layer that already exists in the thin-film transistor structure. The electrode layer is designed to serve dual purposes: electrical conduction and light blocking, thereby eliminating the need for additional light-blocking layers and reducing manufacturing complexity
Solution Approach 2:
The electrode layer is designed to perform multiple functions simultaneously: it serves as both the electrical electrode for the thin-film transistor and as the light-blocking layer. This multi-functional design reduces the total number of layers and manufacturing processes while achieving effective light blocking to prevent photovoltaic effects
2Measurement precision
If additional light-blocking layers are added to block light to the thin-film transistor, then detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent merges the electrode layer and light-blocking layer into a single integrated structure. The electrode layer is positioned and designed to simultaneously perform electrical function and optical blocking function, thereby achieving accurate detection without increasing device complexity
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 effectively blocks light to the thin-film transistor using fewer manufacturing processes, enhancing efficiency and reducing costs while maintaining detection accuracy.
Implementation Method 1
Optical sensors capable of detecting a fingerprint pattern and/or a vein pattern are known
Implementation Method 2
light blocking is required to reduce malfunctions that are caused by a photovoltaic effect of a semiconductor
Data Source
AI summary
A detection device includes a photodiode, and a thin-film transistor coupled to the photodiode. The thin-film transistor includes a semiconductor layer between a light-blocking layer and the photodiode, and an electrode layer between the semiconductor layer and the photodiode, and the electric layer includes a source electrode and a drain electrode of the thin-film transistor. The source electrode extends to a position facing the light-blocking layer with the semiconductor layer interposed therebetween.