Optical and passivation properties of ZnO:fe on silicon substrates

In this study, undoped and Fe doped ZnO thin films were prepared by simple and low cost co-precipitation and then were deposited by spin-coating technique on silicon substrates. The influence of Fe-doping concentration on structural and opto-electronic properties of the prepared films was discussed. Crystalline structure and surface morphology of the deposited films were investigated by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) techniques. Investigations on surface passivation and reflectivity for Fe-doped and undoped zinc oxide thin films indicates the degree of surface passivation which is assessed using FTIR and photoconductance-based methods. As a result, with a minority carrier density (n) of 1013 cm−3, the effective minority carrier lifetime increases from 2 to 95 µs. However, following Fe doped ZnO onto silicon coating, shows that the reflectance is lowered from 32% to roughly 6%.