Optical Gas Sensor Using Nanostructure Photoluminescence
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Solution Overview
Problem
Existing gas sensors are either expensive and difficult to use in situ, or non-selective and prone to contamination, with nanostructure-based sensors facing challenges in conductivity measurement and fragility.
Innovation Solution
An optical gas sensing device utilizing an array of semiconductor-based nanostructures with a high surface-to-volume ratio, which undergo photo-induced adsorption of gas molecules, altering photoluminescence to detect gases without electrical contacting, allowing for reversible and reproducible gas detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct optical spectroscopy methods are used for gas detection, then measurement precision and selectivity are improved, but device cost and operational complexity increase
Solution Approach 1:
The patent replaces complex mechanical/optical spectroscopy systems with a simplified photoluminescence-based detection system. Instead of using elaborate optical paths, monochromators, and detectors required for direct optical spectroscopy, the invention utilizes the natural photoluminescence response of semiconductor nanostructures that directly changes upon gas adsorption, eliminating the need for complex optical measurement apparatus while maintaining detection precision
Solution Approach 2:
The patent changes the detection parameter from measuring direct optical absorption spectra to measuring photoluminescence intensity changes. This parameter transformation simplifies the measurement system while preserving gas detection capability, as the photoluminescence signal directly reflects gas concentration through surface adsorption effects on the semiconductor nanostructures
2Measurement precision
If nanostructure-based sensors with electrical contacting are used, then sensitivity is improved, but reliability and ease of operation deteriorate due to conductivity measurement complexity and fragility
Solution Approach 1:
The patent replaces electrical conductivity measurement systems with optical photoluminescence detection. Instead of requiring electrical contacts, wire bonding, and complex conductivity measurement circuits that introduce fragility and handling complexity, the invention uses optical excitation and photoluminescence signal detection, which are inherently more robust and easier to implement reliably in nanostructure-based sensors
Solution Approach 2:
The patent introduces photoluminescence as an intermediary signal mechanism between gas adsorption and detection. The semiconductor nanostructures serve as transducers that convert gas adsorption events into photoluminescence intensity changes, providing a reliable and contactless detection pathway that avoids the fragility and complexity associated with direct electrical conductivity measurements
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 device is simple, inexpensive, highly sensitive, and reliable, with low energy consumption, suitable for mobile and aggressive environments, and capable of detecting specific gases without hysteresis or fragility issues.
Implementation Method 1
the nanostructures each having a surface which is capable of photo-induced adsorption of gas molecules
Implementation Method 2
The basic principle of the optical gas sensing device relies on the photoluminescence response of semiconductor-based nanostructures upon their exposure to gases
Data Source
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AI summary
An optical gas sensing device (10) is specified comprising a gas detecting unit (1) wherein the gas detecting unit (1) comprises an array of semiconductor based nanostructures (1a), the nanostructures (1a) each having a surface which is capable of photo-induced adsorption of gas molecules (3) leading to a non-radiative surface-related recombination.