On the correlation between morphology and gas sensing properties of RGTO SnO2 thin films

Abstract In this paper, we present the results of studies on optimalisation of morphology of the SnO 2 thin films grown by RGTO technique for application as gas sensor structures. The Sn thin films were grown on Si(111) wafer and Al 2 O 3 ceramic plate heated in the range 235–295 °C and subsequently oxidized in dry oxygen atmosphere at high temperature, up to 700 °C. Our studies confirmed that the highest surface coverage of Sn droplets can be reached for the substrate temperature of about 265 °C leading to the highest surface-to-volume ratio of SnO 2 thin films. It was in a good correlation to the optimal gas sensor response and sensor sensitivity of RGTO SnO 2 thin films to nitrogen dioxide NO 2 .