Scrutinizing the untapped potential of emerging ABSe₃ (A = Ca, Ba; B = Zr, Hf) chalcogenide perovskites solar cells

ABS₃chalcogenide perovskites (CPs) are emerging as promising alternatives to lead halide perovskites due to their unique properties. However, their bandgap exceeds the Shockley-Queisser limit. By substituting S with Se, the bandgap is significantly reduced, shifting it from the visible into the near-infrared region. Hence, we have investigated the potential of Se-based absorbers with device structure FTO/TiO₂/ABSe₃ (A = Ca, Ba; B = Zr, Hf)/NiO/Au using SCAPS-1D. We analyzed the critical parameters impacting each layer of the solar cell. Notably, we achieved an enhanced light absorption (~ 26.5%) at an optimal absorber thickness (500 nm), intensifying carrier generation. Additionally, we observed an increase in V_OC (1.03 V) due to improved quasi-Fermi level splitting and a reduction in energy loss (0.45 V) across all solar cells with an optimal absorber carrier concentration (10¹⁶  cm^-3). Overall, the optimization resulted in improvements in PCE by the difference of 20.14%, 20.44%, 14.33%, and 14.56% for CaZrSe₃, BaZrSe₃, CaHfSe₃, and BaHfSe₃ solar cells, respectively. The maximum PCE of over 30% was attained for both CaZrSe₃and BaZrSe₃ solar cells, attributed to their narrow bandgap, enhanced light absorption (53.60%), high J_SC (29 mA/cm²), and elevated generation rate of 1.19 × 10²² cm^-2s^-1. Thus, these significant outcomes highlight the potential of these absorbers for fabricating high-efficiency CP solar cells.