Electrical response analysis of doped tin oxide gas sensors under different gases atmospheres

L. FRAIGI, E. MANGANO, M.A. PONCE, C.M. ALDAO, C. MALAGU, M.C. CAROTTA, G. MARTINELLI

Rio de Janeiro, Brasil

Conferencia; 11th International Conference on Advanced Materials; 2009

Semiconductor gas sensors based on tin oxide have been widely accepted for detecting and monitoring oxidizing or reducing gases. The electrical resistance of TixSn1-xO2 sensors under diferent atmospheres was analyzed. Possible mechanisms responsible for the found responses, under different gases conditions, are proposed (1-4). The influence of temperature on the oxygen diffusion into the grains annihilating oxygen vacancies was studied. To fit the experimental results, a simple circuit model that considers a capacitance and a resistance in parallel was employed. An explanation for the resistance variation considering spherical grains with different characteristics is proposed.