Electrical transport, Meyer–Neldel rule and oxygen sensitivity ofBi2S3 nanowires

Abstract

The electrical properties of Bi2S3 nanowire bundles were investigated. The nanowires were synthesized usinga solventless reaction involving a single-source bismuth thiolate precursor andstabilizing organic ligands. For electrical testing, nanowires were dispersed insolution and drop cast onto a substrate with gold contact pads patterned byelectron beam lithography techniques (EBL). Electrical connections were madeby depositing platinum interconnect lines between the nanowires and the goldpads by focused ion beam (FIB) chemical vapour deposition. Current–voltage(I–V) curves were measured under nitrogen as a function of temperature. The data revealedactivated transport that followed a Meyer–Neldel relationship. Annealing under vacuumdecreased the nanowire resistance by nearly four orders of magnitude. The annealednanowires followed an inverse Meyer–Neldel relationship. Illumination with UV lightincreased the current, and air exposure decreased the current under constant applied bias.