Capacitive detection of organic vapours at low ppm level by porous silicon: Role of molecular structure in sensing mechanism

Abstract

Purpose - The purpose of this paper is to present the dependence of capacitive sensing of organic vapours by porous silicon (PS) on its molecular structure for the realization of a organic vapour sensor, compatible with existing silicon technology, with desired miniaturization and selectivity. Design/methodology/approach - The method introduces large surface area of PS obtained by electrochemically etching of silicon wafer for characterization of organic vapours through capacitive sensing. Findings - The method provides a comparative study of sensor response for organic vapour molecules of different structures and leads to an insight into the sensing mechanism. Research limitations/implications - The surface of PS has been stabilized by thermal oxidation process. Practical implications - The method is useful for the development of a simple, cost-effective sensor for selective gas analysis. Originality/value - The result is an outcome of regular experimental work carried out to observe the capacitive sensing behavior of PS for different organic vapours. © 2010 Emerald Group Publishing Limited. All rights reserved.