Performance Optimization of Cs 2 AgInBr 6 -based Inorganic Perovskite Solar Cells via Hole Transport Layer Engineering: A SCAPS-1D Simulation Study

This study systematically explored the impact of four HTL materials (CuI, Se-Te:Cu 2 O, Cu 2 O, CuSCN) on the performance of Cs 2 AgInBr 6 -based inorganic perovskite solar cells based on the SCAPS-1D simulation platform. The J-V characteristics, energy band alignment (CBO/VBO) and carrier dynamics were deeply analyzed by constructing the n-i-p device structure (Glass/ITO/ZnSe/Cs 2 AgInBr 6 /HTL/Au). The study found that Se-Te:Cu 2 O aligns with the optimized energy band (CBO = -0.57 eV, VBO = +0.16 due to its high hole mobility (1297 cm 2 /Vs) shows optimal performance, and its physical mechanism is: a moderate CBO forms a "spike-type" energy band structure, which effectively blocks electron return while avoiding excessively high interface potential barriers; a slightly positive value of VBO promotes the efficient injection of holes from the perovskite layer to the HTL under the action of the built-in electric field. The high hole mobility significantly shortens the carrier transit time and reduces the body recombination probability, while good band alignment enhances the built-in electric field and thereby increases Voc. Thickness optimization shows that the 600 nm perovskite layer and 200 nm HTL can achieve the best balance of light absorption and recombination loss, ultimately achieving a device efficiency of 26.30%. This study reveals the selection mechanism of HTL materials from the physical nature of carrier transport and recombination, and provides a theoretical basis for interface engineering of high-performance inorganic perovskite batteries.