Influence of the microstructure of semiconductor sensor materials on oxygen chemisorption on their surface

Abstract
The correlations between the microstructure and oxygen chemisorption on the surface of nanocrystalline SnO2 and In2O3 were established. The activation energy of oxygen chemisorption was estimated, and the chemisorbed species dominating in the temperature range 200–400°C (working temperature range of semiconductor gas sensors) was identified. An increase in the crystallite size tends to decrease the effective activation energy of oxygen chemisorption and to increase the surface coverage with chemisorbed oxygen and the contribution from atomic species.