Tuning of operation mode of ZnO nanowire field effect transistors by solvent-driven surfacetreatment

Abstract

We report on the adjustment of the operation voltage in ZnO nanowire field effecttransistors (FETs) by a simple solvent treatment. We have observed that by submergingZnO nanowires in isopropyl alcohol (IPA), the surface of the ZnO nanowires is etched,generating surface roughness, and their defect emission peak becomes stronger. Inparticular, ZnO nanowire FETs before IPA treatment operate in the depletion-mode, butare converted to the enhancement-mode with a positive shift of threshold voltage aftersubmersion in IPA. This solvent treatment can be a useful method for controlling theoperation mode of ZnO nanowire FETs for wide applications of nanowire-based electronicdevices and circuits.