Tuning electronic properties of In2O3 nanowires by doping control

We present two effective routes to tune the electronic properties of single-crystalline In2O3 nanowires by controlling the doping. The first method involves using different O2 concentrations during the synthesis. Lightly (heavily) doped nanowires were produced by using high (low) O2 concentrations, respectively, as revealed by the conductances and threshold voltages of nanowire-based field-effect transistors. Our second method exploits post-synthesis baking, as baking heavily doped nanowires in ambient air led to suppressed conduction and a positive shift of the threshold voltage, whereas baking lightly doped nanowires in vacuum displayed the opposite behavior. Our approaches offer viable ways to tune the electronic properties of many nonstoichiometric metal oxide systems such as In2O3, SnO2, and ZnO nanowires for various applications.