Specific response of ultra‐thin metal oxide films to gas

Abstract

Tin and indium oxide ultra‐thin film (UTF) based structures are investigated in the present study. Current‐voltage characteristics (IVC) are measured in the samples by a contact current mode of scanning probe microscopy (SPM). It is proved that the IVC splits into two paths corresponding to increase and decrease of applied voltage, respectively. Detailed investigations of the electrical properties of the ultra‐thin metal oxide (MOX) films revealed a dependence of the IVC on the structure of the films, on initial conductivity and on the surrounding gases. It was proved that the IVC is typically split only if the maximum dc‐voltage exceeds some critical magnitude that is not the same in indium and tin oxide based films. The properties of the ultra‐thin MOX structures are explained in terms of distribution of stoichiometry in MOX based nanometer systems. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)