Boosting bifacial efficiency in inverted perovskite solar cells: 95% bifaciality and 28% PCE through materials and device engineering

Abstract

This study reports a breakthrough in bifacial inverted perovskite solar cells (BIPSCs) by achieving one of the highest reported bifacial efficiencies through advanced drift-diffusion simulations in SCAPS-1D. Unlike conventional approaches, which often focus solely on front illumination, this work optimizes BIPSCs for both front and rear illumination, attaining an impressive bifaciality factor of 95%. The initial device architecture, FTO/Me-4PACz/MAPbI₃/LiF–C₆₀–SnO₂/AZO, exhibited simulated power conversion efficiencies (PCEs) of ∼24% under front illumination and ∼23% under rear illumination, with a high bifaciality factor (B_f) of 95%. To further enhance performances, various hole transport layers (HTLs), including CuCrO₂, CBTS, CuAlO₂, Me-4PACz, and Mg:CuCrO₂, as well as electron transport layers (ETLs) such as BaSnO₃, NiCo₂O₄, Cd_0.5Zn_0.5S, ZnOS, and MZO, were investigated for their effects on charge transport, energy level alignment, recombination losses, and stability. Critical device parameters including series and shunt resistances, layer thickness, bandgap, and defect density were analyzed to determine the optimal configuration. The optimized structure, rGO/Me-4PACz/MAPbI₃/Cd_0.5Zn_0.5S/AZO, incorporating ohmic contacts and rGO as front contact, exhibited a remarkable PCE of 27.98% under front illumination and 26.66% under rear illumination. These results provide valuable insights for advancing high-efficiency bifacial MAPbI₃-based perovskite solar cells. By combining cutting-edge material selection, strategic device engineering, and in-depth performance optimization, this work represents a significant leap forward in bifacial perovskite solar cell technology, paving the way for next-generation high-efficiency, stable, and commercially viable photovoltaic systems.