Simulation of High open-circuit voltage Perovskite/CIGS-GeTe tandem cell

This research work aims to improve the performance of the tandem solar cells based on a novel design that uses perovskite material as an absorber layer of the top sub-cell and Copper indium gallium selenide (CIGS) and Germanium telluride (GeTe) materials as absorber layers of the bottom sub-cell. Using two different materials with different energy gaps and distinct doping levels as absorbers of the bottom sub-cells leads to improvement of the sub-cell performance. These two absorbers, of the bottom sub-cell layers, act electrically series-connected, which improves the sub-cell voltage but at the same time limits the current density of the sub-cell to the minimum one of the used materials. After studying the performance of both sub-cells with AM 1.5 incident spectrum at room temperature, both are used to configure Perovskite/CIGS-GeTe tandem cells. The performance of the designed tandem cell was studied to find the optimum thickness with the variation of the top sub-cell absorber layer thickness. The results show that PVK/CIGS-GeTe tandem cell has a high power conversion efficiency of 33.48%, open-circuit voltage of 1.972 V, short-circuit current of 20.50 mA/cm², and fill factor of 82.81 %.