Stacked Light Detectors With Shared Switching for Multi-Waveband Pixels
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Solution Overview
Problem
Conventional light detection devices have large pixel areas and small aperture ratios due to light detectors being arranged in the same layer, requiring complex color resist alignment and experiencing time differences in frequency sweep operations across different light wavebands, leading to prolonged sweep times.
Innovation Solution
The light detection device arranges first and second light detectors corresponding to different light wavebands in a stacked manner, sharing a single switch element for frequency sweep operations, eliminating the need for color resist alignment and ensuring synchronized frequency sweeps across different wavebands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If light detectors corresponding to different light wavebands are disposed in the same layer, then the device can detect multiple wavebands, but the overall size of area occupied by pixels becomes excessively large
Solution Approach 1:
The patent transitions from a planar arrangement of light detectors to a three-dimensional stacked configuration. Multiple light detectors corresponding to different light wavebands are arranged in different layers along the vertical direction, allowing multi-waveband detection while significantly reducing the horizontal pixel area occupied by each detector.
2Ease of operation
If different switch elements are used to control frequency sweep operations for light detectors corresponding to different light wavebands, then each detector can be independently controlled, but the aperture ratio of the light detection device becomes small
Solution Approach 1:
The patent merges multiple switch elements into a single shared switch element that controls frequency sweep operations for all light detectors corresponding to different light wavebands. This consolidation reduces the total area occupied by switch elements, thereby increasing the aperture ratio of the light detection device.
3Ease of operation
If different switch elements control frequency sweep operations for different light wavebands, then individual control is possible, but time differences exist in frequency sweep operations and the overall frequency sweep time becomes long
Solution Approach 1:
The patent combines multiple frequency sweep control operations into a single unified control operation executed by one switch element. This allows all light detectors corresponding to different light wavebands to perform frequency sweep operations simultaneously, eliminating time differences between wavebands and reducing the overall frequency sweep time.
4Measurement precision
If light detectors perform color resist alignment according to the corresponding light wavebands, then detection accuracy is improved, but the manufacturing process becomes complicated
Solution Approach 1:
The patent eliminates the need for color resist alignment by arranging light detectors corresponding to different light wavebands in a stacked configuration in the vertical direction. Each light detector is positioned to receive light of its specific waveband directly, achieving detection accuracy without requiring complex color resist alignment processes.
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 significantly reduces pixel area, increases aperture ratio, and shortens frequency sweep time by eliminating time differences and the need for complex alignment processes.
Implementation Method 1
A light detection device detects existence of light according to a process in which electromagnetic waves (light) generate electrical signals
Data Source
AI summary
A light detection device including a substrate, a first light detector, a second light detector, and a switch element is provided. The first light detector is disposed on the substrate and includes a first active layer. The second light detector is disposed between the substrate and the first light detector and includes a second active layer. The switch element is disposed on the substrate. A horizontal projection of the second active layer on the substrate completely falls within a horizontal projection of the first active layer on the substrate. A negative electrode of the first light detector and a negative electrode of the second light detector are electrically connected to the switch element via a first metal layer.