Photoconductive Enhancement of Single-Layer Tin Oxide-Coated ZnO Nanowires

Abstract

In this study, zinc oxide nanowires (ZnO NWs) coated with crystalline tin oxide (SnO(2)) by an ultrasonic spray pyrolysis were investigated. High resolution transmission electron microscopy analysis confirms that a continuous single SnO(2) layer of about 10 nm has been coated on the ZnO NWs. Photoconductivity measurements revealed that the ZnO NWs coated with the single uniform SnO(2) layer had a higher photoconductivity ratio by about a factor of 8 compared to the pristine ZnO NWs, attributed to the multi-photoexcited electrons. Under a steady radiation of UV light (lambda=325 nm), a substantial increase in the steady-state photocurrent is noticeable, suggesting that extra photoinduced charges are transferred from SnO(2) to ZnO NWs.