Banerjee, A and Haldar, Ashim Kumar and Mondal, J and Sen, Amarnath and Maiti, Himadri Sekhar (2002) Bi-layer functionally gradient thick film semiconducting methane sensors. Bulletin of Materials Science, 25 (6). pp. 497-499. ISSN 0250-4707

PDF - Published Version Restricted to Registered users only Download (171Kb) | Request a copy

Abstract

Gas sensors based on metal oxide semiconductors like tin dioxide are widely used for the detection of toxic and combustible gases like carbon monoxide, methane and LPG. One of the problems of such sensors is their lack of sensitivity, which to some extent, can be circumvented by using different catalysts. However, highly reactive volatile organic compounds (VOC) coming from different industrial and domestic products (e.g. paints, lacquers, varnishes etc) can play havoc on such sensors and can give rise to false alarms. Any attempt to adsorb such VOCs (e.g. by using activated charcoal) results in sorption of the detecting gases (e.g. methane) too. To get round the problem, bi-layer sensors have been developed. Such tin oxide based functionally gradient bi-layer sensors have different compositions at the top and bottom layers. Here, instead of adsorbing the VOCs, they are allowed to interact and are consumed on the top layer of the sensors and a combustible gas like methane being less reactive, penetrates the top layer and interacts with the bottom layer. By modifying the chemical compositions of the top and bottom layers and by designing the electrode-lead wire arrangement properly, the top layer can be kept electrically shunted from the bottom layer and the electrical signal generated at the bottom layer from the combustible gas is collected. Such functionally gradient sensors, being very reliable, can rind applications in domestic, industrial and strategic sectors.

Item Type:	Article
Additional Information:	National Conference on Frontiers in Materials Science and Technology, INDIAN INST TECHNOL, KHARAGPUR, INDIA, FEB 22-23, 2002
Uncontrolled Keywords:	Sensor; Semiconductor; Tin dioxide; Functionally gradient
Subjects:	Electronics
Divisions:	Sensor and Actuator
Depositing User:	Bidhan Chaudhuri
Date Deposited:	22 Mar 2012 12:31
Last Modified:	22 Mar 2012 12:31
URI:	http://cgcri.csircentral.net/id/eprint/1328

Actions (login required)

View Item