In this work, a colloid of nanocrystalline ZnO particles was prepared by chemical method, and sprayed on porous silicon (PS) substrate which was prepared by electrochemical etching under a current density of 15 mA/cm2 for 10 min. The initial radius of the ZnO particles was 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. Highperformance rectification was obtained, with high photoresponsivity of 0.54 A/W at 400 nm. The corresponding quantum efficiency was 166.7%. The results show that ZnO on PS structures act as good candidates for making highly efficient photodiodes.
Keywords: ZnO nanoparticles; porous silicon.
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