Performance analysis of a novel lead-free monolithic perovskite/silicon tandem solar cell using SCAPS-1D

Abstract

In solar cells, efficiency is the most critical parameter. In single-junction solar cells, efficiency is always limited, so to increase the efficiency beyond a specific range, we need to switch to a tandem configuration. Tandem configuration is the stacking of two different cells together, termed as top and bottom cells, where the electrical properties of these two cells are different. ln this paper, free perovskite material with a wide band gap of 1.5 eV (CsSnGeI3) is used to make the top cell, and a narrow band gap of 1.12 eV crystalline silicon is used to create a bottom cell. The advantage of using perovskite material is its high light conversion rate, which leads to better efficiency. Power conversion efficiency (PEC) for perovskite cells is up to 30%. The proposed cell is simulated by SCAPS-1D. In this process, the top and bottom cells are calibrated in the standalone conditions before analyzing the tandem configuration, where the optimized thickness for the top cell is 100 nm and that of the bottom cell is 200 nm. To combine both cells, the current of both cells should be matched, where the top cell current acts as a limiting factor. By changing the width of the top cell for a filtered spectrum and integrated filtered power, a matched current of 18.34 mA cm−2 is obtained for the top/bottom cell. The resultant parameters of the proposed tandem solar cell are PCE of approximately 26%, open circuit voltage (Voc) of 1.576 V, fill factor (FF) of 90%, and short circuit current (Jsc) of 18.34 mA cm−2. The proposed device can help develop low-cost applications and high-efficiency tandem solar cells.