Gas Sensor Top Gate Electrode Eliminating Diffusion Bottleneck
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Solution Overview
Problem
Conventional gas sensors with thin film transistors (TFTs) face slow gas sensing speeds due to the time it takes for reaction products to diffuse into the TFT, affecting detection speed and accuracy.
Innovation Solution
The gas sensor design features a top gate electrode made of gas-sensitive material, such as nano gold or nano platinum, which directly contacts the gas, eliminating the need for an analyte layer and allowing for fast detection by changing voltage potential and current flow without relying on diffusion-based reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an analyte layer is coated on the semiconductor layer to enable gas detection, then gas detection capability is achieved, but the sensing speed becomes slow due to diffusion time of reaction products
Solution Approach 1:
The patent removes the analyte layer from the conventional gas sensor structure. Instead of using an analyte layer that requires diffusion-based reactions, the invention directly uses the gate electrode as the gas-sensitive element, eliminating the slow diffusion process while maintaining gas detection capability through direct electrical interaction.
Solution Approach 2:
The patent introduces a gate electrode as an intermediary component between the gas environment and the TFT. This gate electrode, made of gas-sensitive material, directly interacts with gas molecules and transduces the interaction into electrical signals, replacing the indirect diffusion-based mechanism of the analyte layer.
2Reliability
If an analyte layer is used for gas detection, then gas sensing function is provided, but detection accuracy is reduced due to slow diffusion process
Solution Approach 1:
The analyte layer is completely removed from the device structure. The gate electrode itself is configured to be directly exposed to the gas environment, eliminating the need for analyte layer-based detection and its associated diffusion limitations that compromise measurement precision.
Solution Approach 2:
The patent replaces the chemical diffusion mechanism (mechanical/physical process) with an electrical field-based detection mechanism. The gate electrode uses electrical interactions with gas molecules to produce detectable signals, substituting the slow diffusion process with a faster electrical transduction process.
3Reliability
If a conventional TFT structure with analyte layer is used, then gas detection is possible, but the device complexity increases due to multiple layers and components
Solution Approach 1:
The patent merges the gas-sensitive function directly into the gate electrode of the TFT, combining two previously separate functions (gate control and gas sensing) into a single integrated component. This eliminates the need for a separate analyte layer and reduces overall device complexity while maintaining gas detection capability.
Solution Approach 2:
The gate electrode is designed to serve dual functions: traditional electrical gate control for the TFT and gas sensing through its gas-sensitive material properties. This multi-functionality eliminates the need for dedicated separate components, simplifying the overall device structure.
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 design enables precise and rapid gas detection by utilizing the voltage potential changes of the top gate electrode, resulting in improved sensing speed and accuracy without the need for an analyte layer, preventing reaction product formation and enhancing detection efficiency.
Implementation Method 1
a top gate electrode 70 made of a gas-sensitive material such as nano gold and nano platinum
Data Source
AI summary
A gas sensor with instantaneous electrical response and thus detection of gas which meets it includes a substrate, a bottom gate electrode on a surface of the substrate, an insulating layer on the surface of the substrate carrying the bottom gate electrode and completely covering the bottom gate electrode. A semiconductor layer is on a surface of the insulating layer away from the substrate. Both the source electrode and the drain electrode, spaced apart, are located on a side of the semiconductor layer away from the substrate each being coupled to the semiconductor layer. The gas sensor further includes a passivation layer covering the semiconductor layer and a top gate electrode on the passivation layer, the top gate electrode being spaced from both the source and drain electrodes. The top gate electrode is made of electrically-conductive and gas-sensitive material. A method for making same is also disclosed.