The Effect of Ru Substitution on the Electrical and Humidity Sensor Properties of Semiconductor Tin Oxide Film

Abstract

In this study, pure SnO2 and Ru-SnO2 thin films were deposited on Si and glass substrates via sol-gel technique for humidity sensor applications. Transparent solutions were prepared from Sn and Ru based precursors. The solutions were deposited on Si (100) and glass substrates by using spin coating technique which provides thin and smooth films. The thin films were annealed at 600o C for 1 hour in air to obtain SnO2 based films. The structural and electrical properties of the films were characterized by XRD, SEM, source/meter system respectively. The AC and DC electrical conductivity of the pure and Rudoped SnO2 films were determined. Humidity sensing properties were measured changing the electrical resistance for different humidity levels at room temperature. The humidity adsorbtion kinetics of these films was investigated by quartz crystal microbalance (QCM) technique.