Electronic properties of light-emitting p-n hetero-junction array consisting of p(+)-Si and aligned n-ZnO nanowires

Abstract

Hetero-junction array of p(+)-Si/n-ZnO nanowires (NWs) was fabricated via contacting of aligned ZnO NWs onto a patterned p(+)-Si substrate. Current-voltage (I-V) measurement on the p-n junction showed a rectification behavior with a high rectification ratio of 10(4) at +/- 3V. In addition, the enhancement of forward current as well as the decrease of the turn-on voltage was observed with the application of negative gate bias and noticeable p-type gate dependence, which was explained in terms of asymmetric shift of the Fermi levels with gate bias in the suggested energy band diagram. Such formed hetero-junction devices showed strong UV sensitivity of 2 x 10(4) under reverse bias of -3 V and electroluminescence in both UV and visible ranges, suggesting its potential applicability in optoelectronic devices. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792302]