Optoelectronic coupling of perovskite/silicon heterojunction tandem solar cell by SCAPS simulation

As for perovskite/silicon heterojunction tandem solar cell, we systematically studied on the impact of bulk defect density, electron/hole capture cross sections, perovskite bandgap, and thickness on the performance of perovskite top cells by SCAPS simulation. Additionally, we also explored how the thickness of both the silicon and the transparent conductive oxide (TCO) films influences the efficiency of the crystalline silicon bottom cells. The highest efficiency (η) achieved for a perovskite solar cell was 28.72% (Jsc=28.00 mA/cm2, Voc=1.24 V, FF=82.73%), while for a silicon solar cell, it reached 29.06% (Jsc=42.65 mA/cm2, Voc=0.80 V, FF=85.16%. Moreover, by optimizing parameters such as a perovskite bandgap of 1.50 eV with a thickness of 354 nm and a silicon substrate thickness of 125 µm, we successfully engineered optoelectronic coupling through current matching, achieving an optimal efficiency of 43.97% (Jsc=26.76 mA/cm2, Voc=2.04 V, FF=80.54%) for a two-terminal (2-T) tandem solar cell. Similarly, when the bandgap of perovskite is set at 1.45 eV with a thickness of 500 nm and silicon substrate thickness at 125 µm, we obtained an optimal four-terminal (4-T) tandem solar cell η reaching up to 43.96%. These results have important implications for the selection of bandgap and thickness of perovskite and silicon substrate thickness in the practical preparation of 2-T and 4-T tandem solar cells.