simulation and characterization of multi-junction solar cells with perovskite/silicon absorbers

As global demand for sustainable energy continues to rise, research into photovoltaic technologies has accelerated significantly. however, the presence of toxic lead in conventional perovskite solar cells poses serious environmental and regulatory challenges, impeding large-scale commercialization. to address this issue, this study investigates the replacement of the conventional ch₃nh₃pbi₃ absorber with the non-toxic ch₃nh₃gei₃ in a perovskite/silicon tandem configuration. the proposed device, structured as fto / tio₂/ ch₃nh₃gei₃ / c-si(n) / c-si(p) / c-si(p⁺), was numerically simulated using scaps-1d software. simulation outcomes indicate enhanced performance, achieving a power conversion efficiency (pce) of 28.98%, short-circuit current density (jsc) of 43.51 ma/cm², open-circuit voltage (voc) of 0.78 v, and fill factor (ff) of 85.10%. these findings confirm the potential of ch₃nh₃gei₃ as an eco-friendly and high-performing replacement for lead-based absorbers in tandem solar cell applications, yielding a 0.9% absolute increase in pce over the reference lead-containing cell.