The Optoelectronic Properties of PbS Nanowire Field-Effect Transistors

We report on the optoelectronic properties of individual PbS nanowires prepared by gas-phase substitution reaction of pregrown CdS nanowires. The PbS nanowires synthesized by this method were found to be single crystals with high quality. A combination of electron-beam lithography and a lift-off process was utilized to fabricate individual 62-nm-thick PbS nanowire field-effect transistors (FETs). The nanowire FETs showed pronounced photoconductivity under light illumination while they were highly resistive in the dark environment. The conductivity increased by more than 40 folds in the presence of light. Our results are the first demonstration of the highly efficient photoresponse of individual single-crystalline PbS nanowires and provide insights into future works on nanostructured PbS optoelectronics.