Enhanced performance of In₂O₃ nanowire field effect transistors with controllable surface functionalization of Ag nanoparticles

Indium oxide (In₂O₃) nanowire field effect transistors (FETs) have great potential in electronic and sensor applications owing to their suitable band width and high electron mobility. However, the In₂O₃ nanowire FETs reported previously were operated in a depletion-mode, not suitable to the integrated circuits result of the high-power consumption. Therefore, tuning the electrical properties of In₂O₃ nanowire FETs into enhancement-mode is critical for the successful application in the fields of high-performance electronics, optoelectronics and detectors. In the work, a simple but effective strategy was carried out by preparing Ag nanoparticle functionalized In₂O₃ NWs to regulate the threshold voltage (V_th) of In₂O₃ NW FETs, successfully achieving enhanced-mode devices. The threshold voltage can be regulated from −6.9 V to +7 V by controlling Ag density via deposition time. In addition, the devices exhibited high performance: huge I_on/I_off ratio > 10⁸, large maximum saturation current ≈ 800 mA and excellent carrier mobility ≈ 129 cm² Vċs⁻¹. The enhanced performance is attributed to the surface passivation by Ag nanoparticles to reduce the density of traps and the charge transfer between traps and the nanowires to regulate the V_th. The result indicates the application of metal nanoparticles significantly improve oxide NW for low-power FETs. (paper)