Design and analysis of inorganic tandem architecture with synergistically optimized BaSnS3 top and AgTaS3 bottom perovskite Sub-Cells

Perovskite materials are revolutionizing the solar cell (SC) industry, continually enhancing their properties and establishing a prominent photovoltaic technology. Among these, BaSnS₃ (BTS) and AgTaS₃ (ATS) stand out for their strong potential as absorber layers. These inorganic chalcogenide perovskites address the drawbacks of their organic counterparts, being both lead-free and non-toxic, thereby making them highly suitable for photovoltaic (PV) applications. The exploration of BTS and ATS as absorber layers in a tandem solar cell’s top and bottom cells has yielded remarkable outcomes. The innovative tandem solar cell design features a top cell structured as n-WS₂/p-BaSnS₃/p⁺-MoS₂ and a bottom cell configured as n-WS₂/p-AgTaS₃/p⁺-GeS. This theoretical study using SCAPS-1D demonstrates a high efficiency of 42.57 % with a V_OC of 2.03 V, a J_SC of 23.29 mA/cm², and an FF of 89.85 %. These impressive results are achieved with adjusted layer thickness, carrier doping and defect levels, highlighting the strong potential of BaSnS₃ and AgTaS₃ photoactive materials. The findings reveal the viability of innovative, all-inorganic perovskite-based tandem solar cells, offering a promising avenue for future sustainable and high-efficiency photovoltaic device technologies.