Surface Properties of Nanocrystalline SnO 2 – x Thin Films with Yb and Sb Additives for Resistive Gas Sensors

Nanocrystalline films of tin dioxide with ytterbium and antimony additives are prepared from a composite target by reactive magnetron sputtering. The electrical resistance of the films increases upon heating from 180 to 400°C due to the field effect caused by surface-adsorbed oxygen, which subsequently captures electrons from the film, and decreases because of the reaction between oxygen ions and the vapor of organic reagents. Resistive gas sensors show enhanced sensitivity and selectivity to a number of organic solvents.