SnO2-nanowires grown by catalytic oxidation of tin sputtered thin films for formaldehyde detection

The aim of the present work is to test the sensing behaviour of tin dioxide nanowires, which have been grown directly onto a sensing device. This device consists in an alumina substrate provided with platinum interdigitated microelectrodes and a Pt heater on the reverse side. The nanowire growing process based on a vapour–liquid–solid method consists of three steps: deposition of a tin thin film by DC sputtering, a 5 nm-thick Au layer deposition and an annealing treatment in the presence of oxygen for the growth of the SnO2 nanowires.These samples have been tested under different concentrations of formaldehyde (HCHO), showing a high sensitivity and very short response and recovery times even at low operating temperatures (130 °C).