Thin-film In-doped V-catalysed SnO2 gas sensors.

Thin-film In-doped V-catalysed SnO2 gas sensors are discussed and compared with Pt-catalysed In-doped or undoped SnO2 gas sensors. The In acceptors are implanted, while the catalysts are directly evaporated onto the active sensor layer. The V/In catalyst/dopant combination leads to thin-film sensors highly sensitive to NO2, while nearly no cross sensitivity to CO, CO2, H2 and CH4 is detectable. The maximum conductivity change of the V-catalyst In-doped SnO2 sensor in NO2-enriched synthetic air occurs at about 200 degree C.