科研之友
微信
新浪微博
Facebook
分享链接
摘要
Ultraviolet photoconductivity in zinc oxide ( ZnO) nanoneedles grown on the surface of a multilayer structure comprised of ZnO film ( 50 nm)/Zn layer ( 20 nm)/ZnO film ( 2 mu m) fabricated on a stainless steel substrate using an unbalanced magnetron sputtering technique is reported. It was observed that the multilayered structure with ZnO nanoneedles exhibited enhanced ultraviolet photoconductivity in comparison to the ZnO films that were without nanoneedles. The enhancement in the photoconductivity is attributed to the increase in the quantum yield of the photogenerated charge carriers due to the presence of nanoneedles. A successive slow photoresponse transient following after a fast rise is due to the establishment of equilibrium between the charge carriers in the conduction band and the trapping centers created due to the shallow defects in the ZnO film. The observed photoresponse is critically analyzed on the basis of trapping levels created by the oxygen species during the high pressure deposition of the ZnO multilayer. Results show the promise of ZnO nanostructures in ultraviolet detection applications.
- 出版日期2007-11-28
