Metal oxide based nanostructure engineering: electrical and gas sensitive properties of structurally modified SnO2 nanowires

Abstract

The paper presents results of the research aimed at the engineering of nanostructures (NSs). SnO2 nanowires (NWs) were grown via vapor-solid mechanism at a synthesis temperature of 900°С in a modified set-up allowing the NS morphology be encoded in a programmable way along its length. The Ti/Au (20/500 nm) electrical contacts to individual NWs were deposited via consequent PVD vacuum deposition process to obtain gas sensitive chemiresistors. Electrical properties and gas-sensing performance of the obtained monocrystalline NSs with a modified shape were investigated using hydrogen and oxygen gases. It was established that structurally modified NWs, due to the presence of narrow segments, exhibit better gas-sensitive characteristics in comparison with straight NWs. Obtained results are discussed from the positions of single-crystal “neck” formation in NSs and their influence on transport properties of NWs. 1. Introduction