Large-area and nanoscale n-ZnO/p-Si heterojunction photodetectors

Abstract

The article reports the results of our experimental investigation on the effect of UV light on the characteristics of n-ZnO/p-Si heterojunction. c-Axis oriented zinc oxide (ZnO) films were deposited by thermal evaporation technique on p-type silicon (Si) substrates to form ZnO/Si heterojunctions. Both large-area and nanoscale heterojunction configurations were studied. The measured current-voltage characteristics in dark and illuminated conditions confirm the rectifying behavior of the heterojunctions and an excellent UV response. The responsivity values were measured to be of 0.18 and 0.12 A/W to UV light (365nm) for large-area and nanoscale heterojunctions, respectively. The values are comparable with those offered by other commercial UV detectors. The nanoscale heterojunction device can find applications in nanophotonics. © 2011 American Vacuum Society.