Room temperature hydrogen sensor with ultrahigh-responsive characteristics based on Pd/SnO2/SiO2/Si heterojunctions

A series of Pd/SnO2/SiO2/Si heterojunction sensors were produced using magnetron sputtering method. It is found that the Pd/SnO2/SiO2/Si heterojunction exhibits ultrahigh H-2 response of similar to 17363% to 1.0% H-2 at room temperature, and has fast response and recovery, excellent stability and selectivity. Therefore, this kind of heterojunction may be a promising candidate for effective H-2 detection at room temperature. The H-2 response characteristics and the optimum operating voltage of the sensors is modulated by the interface barrier potential between SnO2 and Si, which can be understood by the interfacial energy band characteristics of the Pd/SnO2/SiO2/Si heterojunction. (C) 2015 Elsevier B.V. All rights reserved.