Preparation and Investigation of Photodetectors based on ZnO Crystals

The nanocrystal and microcrustal ZnO are formed by Atmosphere Pressure Chemical vapor deposition (APCVD) on single crystalline as well as Porous Silicon substrate. ZnCl2 and O2 were used as Zn and O sources respectively, while N2 used as a carrier gas. The effect of deposition temperatures in range 450-750oC on the formation and ZnO crystlinity are investigated. The chemical bonds, structural, morphological, and atomic composition of ZnO crystal were studied by using Fourier Trans Formation Infrared Radiation (FTIR), X-ray diffraction(XRD), Filed Emission Scanning Electron Microscopy (FESEM) and Energy dispersive of X-ray (EDX). The FTIR spectra at different anodic showed the characteristics of vibration modes of Porous Silicon, the spectra is also used to study the types for vibration modes for ZnO/Si and ZnO/PSi at different deposition temperatures. The X-ray diffraction showed a polycrystalline structure for ZnO having hexagonal wurtzite lattice distribution reflection peaks (002), (101) and (100). The best ZnO crystalline is obtained at a substrate temperature (6500C).