Numerical Study of the Influences of ZnGeO Buffer on Electrical Features of Cu2O Solar Cell

In this paper, the effect of germanium content in Zn1-xGexO as a buffer layer on the performance and efficiency of a solar cell based copper oxide (Cu2O) is investigated. The physical parameters of the solar cell model were selected according to the experimental data and then the new parameters of ZnGeO buffer layer was calculated based on the interpolated parameters of the energy levels of the band structure of binary compounds ZnO and GeO2 to study the solar cell performance for the germanium composition, ranged from 0.35 to 0.75. First, the accuracy of the initial model of the solar cell was verified by comparing its electrical characteristics with experimental data. Then, the characteristics of the initial model were analyzed and characterized in presence of buffer layer. By examining the cell efficiency for the changes of buffer composition (35% to 75% germanium), the minimum efficiency was observed 5.31% at x = 0.35 and the maximum was 7.02% at x = 0.65. The results show that using Zn0.35Ge0.65O buffer, the short circuit current of the cell reaches 11.15 mA with an open circuit voltage up to 1.08 volts.