Enhancement-mode field-effect transistors based on Ti-doped In2O3 nanowires fabricated by electrospinning

Abstract

Recently, indium oxide (In2O3) semiconducting nanowires (NWs) have been extensively explored as building blocks for numerous electronic applications. However, most of the field-effect transistors (FETs) based on In2O3 NWs were operated in depletion mode (D-mode), which exhibits negative threshold voltage (VTH) and non-zero current with zero bias. Besides, these devices based on In2O3 NWs still suffer from high leakage current and low on-off current ratios (Ion/off). In this report, high-performance enhancement-mode (E-mode) FETs based on Ti doped In2O3 NWs were successfully integrated. It was found that the device performance could be effectively modulated by adjusting the doping concentration of Ti. The FETs based on In2O3 NWs with Ti doping concentration of 3 mol% exhibited a saturation current of 4.69 × 10−4 A, a subthreshold swing (SS) of 1.54 V/decade, an on/off current ratio of ~1.5 × 108, and a field-effect mobility of 2.53 cm2 V−1 s−1. When high-κ ZrOx dielectrics were successfully integrated into the FETs, the mobility and SS of the designed device were improved to 12.67 cm2 V−1 s−1 and 150 mV/decade, respectively. The inverters based on InTiO NWs/ZrOx FETs were constructed and showed a gain of ~9.5. All of these results demonstrate that Ti-doped In2O3 NWs are promising candidates for large-scale, high-performance and low-power electronic devices.