Tandem solar cells represent a transformative approach in overcoming the efficiency ceiling of single‐junction photovoltaics by harnessing a wider portion of the solar spectrum. In this study, a high‐performance two‐terminal tandem device is designed by integrating a CsSn 0.5 Ge 0.5 I 3 perovskite top subcell (Front contact/ZnO/CsSn 0.5 Ge 0.5 I 3 /MoS 2 / Back contact) with a crystalline silicon bottom subcell (Front contact/n ‐ Si/pSi/p + Si/Back contact). In standalone conditions, the optimized top perovskite subcell achieved a power conversion efficiency (PCE) of 19.66%, delivering an open‐circuit voltage (V oc ) of 1.08 V, short‐circuit current density (J sc ) of 20.69 mA/cm 2 , and fill factor (FF) of 87.79%. The complementary bottom silicon sub‐cell exhibited a PCE of 25.52% with V oc = 0.69 V, J sc = 43.24 mA/cm 2 , and FF = 84.48%. When configured in tandem and optimized under current‐matching conditions with different input material parameters, the device achieved remarkable performance with significantly enhanced with an impressive overall efficiency of 31.42%, V oc = 1.76 V, J sc = 20.69 mA/cm 2 , and FF = 86.24%. This significant enhancement in V oc and FF underscores the synergistic effect of combining a narrow‐bandgap silicon absorber with a wide‐bandgap CsSn 0.5 Ge 0.5 I 3 perovskite in tandem configuration. The findings highlight the immense potential of hybrid perovskite–silicon tandem architectures to drive the next generation of high‐efficiency, cost effective photovoltaic technologies.
Islam et al. (Sun,) studied this question.