Volatile gas sensing properties of phase and composition gradient SnO x thin films by combinatorial sputter deposition

Abstract

Compositionally gradient tin oxide thin films were prepared by co-sputtering from tin and tin oxides targets. After annealing at 450°C, gradient crystalline phases of SnO and SnO2 were fabricated on a single sensor. Acetone, ethanol, and ethylene were utilized to investigate sensing properties of the gradient tin oxide sensor. Coexisting p-type SnO and n-type SnO2 affect the direction of electrical resistance and the response during gas reaction and recovery. Construction of gradient tin oxide film in terms of composition and crystalline phase demonstrates the design of a gas sensor for the selective gas detection via the combinatorial approach. © 2012 The Electrochemical Society.