Optimization of efficient monolithic perovskite/silicon tandem solar cell

Solar cells based on multi-junctions are considered to be the most efficient way of improving the cell's sunlight to electrical energy conversion efficiency. In this paper, we simulated monolithic tandem solar cell comprised of high and low bandgap materials i.e., perovskite/silicon layers, separated by a recombination layer made of Spiro-MeOTAD/Silicon, a window layer formed from zinc oxide (ZnO), a buffer layer formed from cadmium sulfide (CdS), and a heavily doped back surface field layer made of n⁺⁺Si to stop the recombination at the back surface. The stated structure is investigated numerically and optimized for different parameters, which include bandgap, thickness of active layers, and dopant concentration. The obtained photovoltaic parameters are: open circuit voltage (V_oc) =1.779V, short circuit current density (J_sc) =20.19 mA/cm², fill factor (FF) = 82.22 %, and efficiency (η) = 28.50 %, respectively. Additionally, we tested the optimized solar cell design for high temperatures, and it turned out that temperature had very little effect on the cell, showing superior performance than conventional multi-junction structures.