Engineering and Technology Journal

Abstract

In this work a colloid of nanocrystalline ZnO particles is prepared by
chemical method, and then sprayed on porous silicon substrate which is prepared
by electrochemical etching under a current density of 15mA/cm2 for 10 min. The
initial radius of the ZnO particles is found to be (2.2 nm). FTIR spectra exhibit the
presence of Zn – O bond which indicates the formation of ZnO particles. Also
spectra reveals the formation of SiHx (x=1-2) and Si-O bond which indicates the
presence of porous layer. High performance rectifying was obtained, with high
photoresponsivety of 0.54 A/W at 400 nm. The corresponding quantum efficiency
was 166.7%.The results show that ZnO on porous silicon (PS) structures will act as
good candidates for making highly efficient photodiodes.