Multilayer Optical Sensor Structure for Visible-to-Mid-IR Detection
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Solution Overview
Problem
Current optical sensors are limited in their ability to detect light across a wide spectrum, particularly in the visible, near-infrared, short-wave infrared, and mid-infrared ranges, due to the lack of effective multi-layer structures that can efficiently absorb and process light across these wavelengths.
Innovation Solution
The optical sensing apparatus incorporates multiple photo-detecting layers with specific absorption regions, buffer layers, and doping configurations, including silicon, black phosphorus, and germanium, to enhance light absorption and carrier amplification, with graphene or other two-dimensional materials used to improve performance across the visible to mid-infrared spectrum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple photo-detecting layers are stacked to detect different wavelength ranges, then the spectral detection range is improved, but the device complexity increases
Solution Approach 1:
The optical sensing apparatus divides the detection spectrum into multiple segments by stacking different photo-detecting layers (first photo-detecting layer for visible/NIR, second photo-detecting layer for SWIR/MIR) with buffer layers between them. Each layer is optimized for specific wavelength ranges, allowing comprehensive spectral coverage while maintaining manageable structural complexity through systematic segmentation.
Solution Approach 2:
The patent implements a nested multi-layer structure where photo-detecting layers and buffer layers are stacked sequentially, with each layer nested within the overall device architecture. The buffer layers are positioned between and around the photo-detecting layers, creating a nested configuration that integrates multiple functional layers into a compact vertical structure.
2Measurement precision
If buffer layers are added between photo-detecting layers to prevent carrier relaxation and oxidation, then the sensitivity is improved, but the device complexity increases
Solution Approach 1:
Buffer layers serve as intermediary elements positioned between the first and second photo-detecting layers. These buffer layers mediate the interaction between adjacent photo-detecting layers by preventing carrier relaxation and material oxidation, thereby protecting the photo-detecting layers while maintaining a relatively simple overall structure.
Solution Approach 2:
The buffer layers are designed as thin protective layers (graphene or other two-dimensional materials) that provide essential protection against carrier relaxation and oxidation. These relatively thin buffer layers offer effective protection with minimal impact on device complexity, acting as cost-effective protective barriers.
3Productivity
If charge carrier amplification is implemented in the first photo-detecting layer, then the detection efficiency is improved, but the device complexity increases
Solution Approach 1:
The first photo-detecting layer incorporates localized p-type or n-type doping regions to create charge carrier amplification zones. This local quality enhancement allows efficient charge carrier multiplication in specific areas of the first photo-detecting layer without requiring complex doping structures throughout the entire device, thereby improving detection efficiency while controlling 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
This configuration enables optical sensors to detect light across a wide spectrum, from visible to mid-infrared, improving sensitivity and efficiency by amplifying charge carriers and preventing carrier relaxation and material oxidation, thus enhancing their applicability in various sensing applications.
Implementation Method 1
a first photo-detecting layer having a first absorption region configured to absorb light in at least a visible spectrum
Implementation Method 2
a second photo-detecting layer formed over the first photo-detecting layer, the second photo-detecting layer having a second absorption region configured to absorb light in at least a mid-infrared spectrum
Implementation Method 3
the first photo-detecting layer includes a charge region configured to amplify charge-carriers generated in the second absorption region
Data Source
AI summary
An optical sensing apparatus includes a first photo-detecting layer having a first absorption region configured to absorb light in at least a visible spectrum; a second photo-detecting layer formed over the first photo-detecting layer, the second photo-detecting layer having a second absorption region configured to absorb light in at least a mid-infrared spectrum; a first buffer layer formed over the second photo-detecting layer; and a second buffer layer formed over the first photo-detecting layer and under the second photo-detecting layer.