Multi-Band Resonant Cavity Photodetector for Visible-NIR Absorption
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Solution Overview
Problem
Existing photodetectors have limited wide spectrum detection capabilities due to narrow band coverage, high power consumption, and low light wave absorption and utilization, particularly failing to simultaneously enhance visible light and near-infrared detection.
Innovation Solution
A wide spectrum multi-band detection structure with selective absorption enhancement is achieved through a substrate with square well-shaped microstructures and metal electrodes, where each sub-pixel unit is designed for specific bands, forming resonant cavities to improve light absorption efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional single-band detection structures are used, then the device is simple to manufacture, but the spectrum coverage is narrow and light absorption efficiency is low
Solution Approach 1:
The detection device is segmented into multiple sub-pixel units, each equipped with specific wavelength filters (red, green, blue, near-infrared) to detect different spectral bands. This segmentation enables multi-band detection capability while maintaining a relatively simple overall structure that can be integrated into existing detector architectures.
Solution Approach 2:
The detection device achieves multi-functionality by integrating multiple detection bands (visible light and near-infrared) into a single device. Each sub-pixel unit is designed to handle specific wavelength ranges, allowing the device to perform wide-spectrum detection without requiring separate detectors for different bands, thus improving versatility while controlling complexity.
2Productivity
If conventional flat detection surfaces are used, then the manufacturing process is simple, but the light absorption and utilization rate is low
Solution Approach 1:
The patent introduces square well-shaped microstructures with curved side surfaces instead of flat detection surfaces. These microstructures form resonant cavities that trap and absorb incident light waves more effectively, significantly improving light absorption efficiency. The curved geometry creates multiple internal reflections, increasing the optical path length and absorption probability without requiring excessively complex structures.
3Adaptability or versatility
If multiple separate detectors are used for different bands, then each detector can be optimized for its band, but the overall device volume and weight increase
Solution Approach 1:
The patent merges multiple detection bands (visible light and near-infrared) into a single integrated detector device. By combining multiple sub-pixel units with different wavelength filters on one detector substrate, it achieves multi-band detection capability while reducing the overall volume and weight compared to using separate detectors for each band. This integration maintains optimization for each band while achieving compact form factor.
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 structure enhances detection efficiency and sensitivity by almost completely absorbing incident light waves across visible and near-infrared bands, integrating multi-band detection units in a single device.
Implementation Method 1
The upper openings of the square well-shaped microstructures are hollow to form a resonant cavity, and the adjacent square well-shaped microstructures in the same sub-pixel unit form a resonant cavity
Implementation Method 2
The principle of photodetectors is that the conductivity of irradiated materials is changed due to radiation
Data Source
AI summary
The invention relates to a wide spectrum multi-band detection structure with selective absorption enhancement and its preparation method. The structure comprises a plurality of sub-pixel units capable of detecting incident light in different bands. Each sub-pixel unit is composed of a square well-shaped microstructure array and a metal lower electrode (2), a photosensitive layer (3) and an upper electrode (4) on the surface thereof. The size and array spacing of square well-shaped microstructures in different sub-pixel units are determined according to the detection bands of the sub-pixel units where they are located. The upper openings of the square well-shaped microstructures are hollow to form a resonant cavity, and the adjacent square well-shaped microstructures in the same sub-pixel unit form a resonant cavity, thus solving the problem that the detector structure in the prior art cannot simultaneously realize visible light-near infrared multi-band absorption enhancement detection.