IR Detector Array Membranes for Robust Spectral Selectivity
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Solution Overview
Problem
Existing IR detectors face limitations in mechanical robustness and thermal isolation due to the use of plasmonic structures connected to the substrate via thin beams, which restricts the integration of thermocouples and affects the overall thermo-electrical conversion efficiency, and thermodiodes require biased voltage, making it difficult to measure small changes in output voltage.
Innovation Solution
An IR detector array with at least two dielectric membranes on a semiconductor substrate, featuring an array of IR detectors with patterned plasmonic layers for controlled IR absorption, allowing for differential signal processing between detectors with and without plasmonic patterns to enhance spectral selectivity and reduce the need for optical filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If plasmonic structures are connected to the substrate via thin beams, then spectral selectivity is improved, but mechanical robustness deteriorates
Solution Approach 1:
The device is divided into multiple dielectric membranes, each carrying specific plasmonic structures for different spectral bands. This segmentation allows each membrane to be optimized independently - some can have robust substrate connections while others focus on spectral selectivity, resolving the contradiction between mechanical strength and spectral performance
Solution Approach 2:
Dielectric membranes serve as intermediary structures between the substrate and the plasmonic detection elements. These membranes provide mechanical support and thermal isolation while allowing the plasmonic structures to function independently, thus improving both mechanical robustness and spectral selectivity simultaneously
2Loss of energy
If thin beams are used for substrate connection, then thermal isolation is improved, but mechanical robustness deteriorates
Solution Approach 1:
The thermal isolation function is segmented and distributed across multiple dielectric membranes rather than relying on thin beams. Each membrane provides thermal blocking while maintaining mechanical integrity, allowing robust substrate connections without compromising thermal isolation performance
Solution Approach 2:
The device uses composite structures combining dielectric membranes with substrate connections. The dielectric materials provide thermal isolation while the substrate provides mechanical support, creating a composite system that achieves both thermal isolation and mechanical robustness simultaneously
3Measurement precision
If thermodiodes are used for IR detection, then detection capability is improved, but device complexity increases due to biased voltage requirement
Solution Approach 1:
The complex biased voltage requirement is extracted and eliminated by using thermopiles instead of thermodiodes. The invention takes out the power supply complexity while maintaining high detection capability through the thermoelectric effect, simplifying the overall device architecture
Solution Approach 2:
The thermopile detectors are self-powered through the Seebeck effect, converting thermal gradients directly into electrical signals without requiring external bias voltage. This self-service mechanism eliminates the need for complex power supply circuits while maintaining high detection precision
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 improves mechanical robustness and spectral selectivity, enabling efficient IR detection and spectroscopic analysis by processing differential signals from detectors with and without plasmonic patterns, thereby enhancing the detection of gas concentrations and reducing the need for complex optical filters.
Implementation Method 1
at least one patterned layer formed within or on said dielectric membrane for controlling the IR absorption of at least one of the said IR detectors
Implementation Method 2
The Seebeck effect causes a slight voltage difference across each thermocouple - resulting in a much large increase in voltage difference across the thermopile
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
We disclose an array of Infra-Red (IR) detectors comprising at least one dielectric membrane (2, 3) formed on a semiconductor substrate comprising an etched portion; at least two IR detectors (4, 5), and at least one patterned layer (7) formed within or on one or both sides of the said dielectric membrane for controlling the IR absorption of at least one of the IR detectors. The patterned layer comprises laterally spaced structures.