Computational Study of Perovskite/Perovskite Lead-free Tandem Solar Cell Devices

Multi-junction (tandem) solar cells comprising several light absorbers with significantly diverse bandgaps demonstrates high potential in reaching the efficiency beyond the single junction Shockley–Queisser (S–Q) efficiency limit due to the absorption of solar spectrum in a wider range of wavelengths. Even though lead-based perovskite solar cells (PSCs) have demonstrated higher efficiencies the toxicity issue of lead restricts the usage of lead-based perovskites as efficient absorber in the solar cells. perovskite materials with low toxicity are being investigated for development of eco-friendly lead-free tandemPSC). We have simulated perovskite/perovskite lead-free tandem solar cells with CsSnGeI3 as top cells absorber and MasnI3 as bottom cells absorber. single-junction solar cells have shown an PCE of 21% and 15% respectively. Whereas the tandem structure has obtained an efficiency of 31%.