Simulation and performance study of Thin film CdSe/GaAs Solar Cell

In this paper we have used P-I-N structure to simulate the current-voltage characteristics of thin film CdSe/GaAs tandem solar cell. The proposed structure contains CdSe with direct band gap of 1.74eV as top cell and GaAs with direct band gap of 1.42eV as bottom cell. The top cell contains the photovoltaic absorption layer with a band gap larger than bottom solar cell. It has been observed that there is increase in photocurrent by increasing in the optical path length where electron hole pairs are produced as more photons have chances to get absorbed, results in increasing the efficiency of the solar cell. There is a significant improvement in parameters like, short circuit current density I
sc
, the open circuit voltage V
oc
, the fill factor FF and the Conversion efficiency has been observed in comparison to conventional structure. The power conversion efficiency of solar cell increases by 31.4%, short circuit current increases by 19.9%, open circuit voltage by 5.7%, Fill factor by 4.87%.