Design and optimization of bifacial double perovskite solar cells under albedo conditions

This study Investigates an optimized design of a bifacial perovskite solar-cell using a non-toxic, high-efficiency Cs₂AgBiI₆ absorber. An efficient device configuration was proposed, integrating indium zinc oxide as the transparent front electrode, MoS₂ as ETL, and MgCuCrO₂ as HTL. The proposed design is systematically evaluated against conventional design employing TiO₂ and ZnTe as the charge transport layers, respectively. Through numerical simulations, the study carried out an extensive optimization process adjusting absorber and transport layer thicknesses, fine-tuning doping concentrations, and improving interface quality. These refinements were aimed to reducing losses, and enhancing the efficiency. To assess real-world performance, surface reflectance from various environments, including grass, concrete, and snow, was also considered. As a result, the optimized bifacial structure achieved notable gains in performance. Under front-side illumination, it recorded a Voc of 1.06 V, a Jsc of 22.18 mA/cm² a FF of 81.5 %, and an efficiency of 19.23 %. The rear-side illumination also yielded a strong response, with an even higher efficiency of 19.21 %, FF of 82.92 %. Jsc of 11.10 mA/cm² and Voc of 1.04 V underscoring the effectiveness of the design improvements. Besides, a further detailed investigation into alternative CTL materials is conducted to enhance performance and suppress interface defect losses. Candidate materials included WS₂, SnS₂, BCP, and BaSnO₃ as ETLs, and NiO, MoO₃, FeS₂, and Cu₂O as HTLs. Among these, the SnS₂/Cu₂O configuration demonstrated superior performance, achieving 22.54 % efficiency under front-side illumination and 25.07 % under back-side illumination. These results highlight the importance of careful CTL selection and justify the use of SnS₂ and Cu₂O in the proposed architecture. Altogether, the findings demonstrate the strong potential of lead-free, double PSC in bifacial photovoltaic applications.