Optoelectronic properties of ZnO/PS/n-Si Heterojunctions


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