Organotin films deposited by laser-induced CVD as active layers in chemical gas sensors

In this work, an organotin film obtained by L-CVD at 193 nm from tetramethyltin was used as active layer in a conductometric gas sensor. As it was stated by in situ surface analysis, the 'as deposited' material contained Sn and C. However, exposure to a large dose of O2 or air determined the formation of a thin SnO2 layer covering the remaining film, which was less oxidised and had an oxygen concentration gradient in its depth. Electrical tests of the sensors showed high sensitivity and short response time for the detection of NO2. Satisfactory performances were observed also with reducing gases. In this case, the high sensitivity measured for H2 and ethanol, in comparison to CO and hydrocarbons, indicated the possibility to use the sensor for selective revelation. © 1998 Elsevier Science S.A. All rights reserved.