Development of Tin Oxide based Thick Film Array for Chemical Gas Sensors

Abstract

This project report focused on the development of an array of chemical gas sensor are intended to detect various gases using four different types of Tin oxide based gas sensor. Gas sensor array based on metal oxide semiconductor materials like tin oxide offer several advantages over its counterparts like simple and fast operation, low cost capability to detect ppm concentration of various gases. The gas sensing mechanism depends on the structural, chemical and electronic properties of the material. It is mainly influenced by the surface region of the grains. Tin oxide semi conducting layers incorporating small amounts of metal and metal oxide dopants (Ce, In, WO3, etc.) are prepared by thick film technology. Tin oxide has been widely used for gas sensing applications where resistance change is used to detect the gases. In this project, we had prepared a wide range of different molar solution of SnO2 to get paste and are deposited by thick film technology. These films were then characterized. Thus by controlling the dopant and its operating temperature the required selectivity and sensitivity for desired gas can be achieved. iv