CAPACITANCE AND RESISTANCE ANALYSIS OF SnO2 THICK FILMS GAS SENSORS

M.A. PONCE, R. PARRA, M.S. CASTRO, C.M. ALDAO.

Toledo

Congreso; Electroceramics X; 2006

  The film resistance is broadly used to characterize a sensor. Studies of capacitance and resistance responses of SnO2 thick films after being exposed to an air atmosphere were carried out.  It was determined that adsorption of oxygen at the grain surface affects the resistance and electrical capacitance of the sensor. Schottky-type potential barriers at grain boundaries were assumed to analyze the sample resistance.  The presence of deep bulk traps were found to play an important role in these systems. Thermionic and tunnelling contributions to electrical conduction have been considered to explain the electrical behaviour of undoped SnO2 samples.