Effect of Ga doping on the electrical and optoelectronic properties of single indium oxide nanowire photodetector

Abstract

Undoped and Ga-doped indium oxide nanowires are synthesized by chemical vapor deposition methods. And single nanowire devices are fabricated by micro-nano processing technology. The electrical and optoelectronic properties of the single undoped and Ga-doped indium oxide nanowire devices are studied. When the undoped and Ga-doped indium oxide nanowires work as a field effect transistor, after Ga doping, the field effect transistor changes from depletion mode to enhancement mode. The hysteresis is suppressed. The dark current of indium oxide nanowire photodetector decreases. From the transfer characteristic curves, the dark current decrease from 4.5 × 10⁻⁷ A to 7.3 × 10⁻¹⁴ A at V_gs= 0 V. The I_light/I_dark ratio and the responsivity become larger. Importantly, the I_light/I_dark ratios at V_gs= 0 V under 245 nm and 365 nm become quite larger after Ga doping, which change from 25.6 and 37.5 to 2.3 × 10⁷ and 1.27 × 10⁸, the I_light/I_dark ratio has been improved for 6 orders of magnitude after Ga doping. Besides, the photoresponse time also becomes shorter. They may be related to the decreased defect states after Ga doping. The results show that Ga doping is beneficial to improve the optoelectronic properties of indium oxide nanowires and promote their further applications in actuator technology with high precision.