Capacitance and resistance measurements of SnO2 thick-films

Abstract

Impedance spectroscopy measurements on SnO2 thick films were carried out in an air atmosphere and for temperatures between 25 0C and 425 0C. Capacitance and resistance analyses reveal the mechanisms responsible for experimental responses. Four different contributions to the overall capacitance and resistance were distinguished and assigned to the bulk, the grain boundary, the electrodes, and the presence of deep traps. The effects of trap states on the electrical behavior of the sensor were explored and a modified equivalent circuit model is proposed.