Design and performance exploration of Pb-free low-cost all-inorganic perovskite-inspired CuAgBi₂I₈ solar cells: theoretical approach

Abstract Organic–inorganic halide perovskites have demonstrated great potential for photovoltaic applications owing to their unprecedented optoelectronic properties and low manufacturing costs. However, the commercialization of this technology is hindered by its thermal instability and inherent toxicity. In this study, SCAPS-1D simulation software was used to study the performance of solar cell based on CuAgBi 2 I 8 , which is a novel inorganic non-toxic lead-free perovskite-inspired material. Different electron transport layers (TiO 2 , In 2 S 3 , ZnO, Zn 0.75 Mg 0.25 O,SnO 2 and SrTiO 3 ) and hole transport layers (CuI, PEDOT:PSS, CuSCN and Cu 2 O) were studied, our research indicated that SnO 2 and NiO formed the optimal combination. Further analysis revealed that the optimal absorption layer thickness was 900 nm, the absorption layer doping concentration should be less than 1 × 10 13 cm −3 and the defect density should be less than 1 × 10 14 cm −3 . The optimal thickness of SnO 2 and NiO was 30 nm, the optimal doping concentration of SnO 2 and NiO was 1 × 10 20 cm −3 , the defect density of absorber layer/SnO 2 and absorber layer/NiO interfaces should be less than 1 × 10 12 cm −3 , C was the optimal back electrode material. Consequently, the optimal device configuration was identified as FTO/SnO 2 /CuAgBi 2 I 8 /NiO/C, the efficiency was improved from original 2.76% to 19.10% after above optimization. These results indicate that solar cell with CuAgBi 2 I 8 as the absorber layer is a potential alternative to organic–inorganic lead halide perovskite solar cells.