Contents
How does a metal oxide gas sensor work?
MOS sensors detect concentration of various types of gases by measuring the resistance change of the metal oxide due to adsorption of gases. Atmospheric oxygen residing on the MOS surface is reduced by the target gases, allowing more electrons in the conduction band of the metal oxide material.
What is metal oxide based gas sensor?
Sensing Mechanism As shown in Figure 1 [23], when O2 molecules are adsorbed on the surface of metal oxides, they would extract electrons from the conduction band Ec and trap the electrons at the surface in the form of ions.
How does a semiconductor gas sensor work?
When semiconductor particles (typically tin dioxide) are heated in air at high temperature, oxygen is adsorbed on the particle surface by capturing free electrons. Until the border is reached, the adsorption equilibrium is attained by increasing the depletion layer thickness.
Where are gas sensors used?
They are commonly used to detect toxic or explosive gasses and measure gas concentration. Gas sensors are employed in factories and manufacturing facilities to identify gas leaks, and to detect smoke and carbon monoxide in homes. Gas sensors vary widely in size (portable and fixed), range, and sensing ability.
Are there gas sensors based on conducting metal oxides?
Gas Sensors Based on Conducting Metal Oxides: Basic Understanding, Technology and Applications focuses on two distinct types of gas sensors based on conducting metal oxides. Ion co read full description The Chapter deals with solid-state electrolyte gas sensors.
What is the gas sensing reaction in oxide semiconductors?
The gas sensing reaction in oxide semiconductors consists of the diffusion of the analyte gas from the ambient atmosphere toward the surface of the oxide semiconductor and the charge-transferring interaction between the analyte gas and the oxide surface.
What are the different types of gas sensors?
Gas sensors mainly include semiconductor gas sensors, electrochemical gas sensors, and contact combustion gas sensors, among which the most promising ones are the semiconductor gas sensors. With the application of a series of oxide semiconductors, including NiO, ZnO, SnO 2, and CdO, the research into metal oxide for gas sensing is popular.
What can MOS-based gas sensors be used for?
However, the sensing properties of MOS-based gas sensors also need to be further enhanced to satisfy the higher requirements for specific applications, such as medical diagnosis based on human breath, gas detection in harsh environments, etc.