The influence of Fe substitution into photovoltaic performance of p-CuO/n-Si heterojunctions

Abstract

Fe-substituted CuO thin films have been prepared by spin coating onto cleaned n-Si and glass substrates at various concentrations (2%, 6%, 10%). The AFM results show that the surface morphology of CuO thin films is strongly influenced by film thickness. The optical band gaps of the films were determined with Kubelka Munk function by using diffuse reflectance data and a reduction of 59 meV in the optical band gap was observed for 10% Fe doped CuO film. The ideality factors and barrier height values of the diodes have been varied between 3.17 and 2.74 and 0.82 and 0.71 eV with the 2%, 6%, and 10% Fe doping, respectively. Additionally, the series resistance (RS) values have been defined via employing the Cheung-Cheung method. The highest and lowest values of RS have been calculated as 1332 Ω for CuO/n-Si and 18 Ω for 6%Fe:CuO/n-Si, respectively. The electrical characteristics of these heterojunction structures have been examined under dark and different illumination intensities. Moreover, their photovoltaic performances have been compared. Furthermore, the power conversion efficiencies of CuO:Fe/n-Si have been calculated and found to be increased from 0.1 to 1.13% with increasing Fe doping.