Electrical and optical properties of single As-doped ZnO nanowire field effect transistors

Abstract

ZnO nanowires with the average diameter of 20 nm and the length of longer than 10 μm were synthesized on GaAs substrate by chemical vapor deposition（CVD）. As-doped ZnO nanowires were obtained by annealing the samples at 600 ℃ for 30 min in oxygen. Single ZnO nanowire field effect transistors（FET） were fabricated by electron beam exposure and magnetron sputtering deposition and Ti/Au deposited as ohmic-contact electrodes. Based on the electrical properties of the single ZnO nanowire FET before and after annealing, we verified that p-type ZnO nanowire can be obtained by As doping effectively. The parameters of the single As doped ZnO nanowire FET were as follows: the transconductance was 35 nA/V, the hole density was 1.4×1018 cm-3, and the mobility was 6.0 cm2/V·s. We also obtained the photoluminescence spectrum of single As-doped ZnO nanowire: strong ultraviolet light at 383 nm, weaker yellow-green light, and red light due to the existence of AsZn-2VZn shallow acceptors.