Numerical simulation of Cs2AgInBr6/Cs4CuSb2Cl12 heterojunction perovskite solar cell: A path to achieve optimized performance

Abstract

In a recent study, inorganic perovskite solar cells based on Cesium continually enhanced solar cell performance. The exceptional stability and performance of the Cs₂AgInBr₆ layer in all-inorganic PSCs make it stand out among the other materials. Unfortunately, the Cs₂AgInBr₆ leads to poor solar energy utilization, significantly reducing light absorption. Based on the matching band structures of Cs₄CuSb₂Cl₁₂ and Cs₂AgInBr₆, the present simulation suggests that Cs₂AgInBr₆/Cs₄CuSb₂Cl₁₂ heterojunction incorporating Cs₄CuSb₂Cl₁₂ rather than HTL. It is then optimized and simulated using simulation software SCAPS-1D to improve sunlight absorption as well as solar cell performance. The open circuit voltage (V_oc) of the Cs₄CuSb₂Cl₁₂ layer is very large compared to other materials due to its wide bandgap (1.6 eV). The large value of V_oc for the proposed heterojunction perovskite solar cell gives a large value of power conversion efficiency. In the final or optimized structure of the heterojunction solar cell, the thickness of Cs₂AgInBr₆ and Cs₄CuSb₂Cl₁₂ layers were selected as 1000 nm and 200 nm, respectively. The Cs₂AgInBr₆ layer had a doping concentration of 1 × 10¹⁷cm³, N_T of 1 × 10¹⁰cm³, and an E_g of 1.47 eV. The Cs₄CuSb₂Cl₁₂ layer has a band gap of 1.6 eV, a defect density of 1 × 10¹⁰ cm³, and an N_A of 1 × 10²⁰ cm⁻³. After the optimization study, the device operates at an ideal stage where V_oc (V) = 1.225, J_sc (mA/cm²) = 29.037, FF (%) = 89.42, and PCE (%) = 31.83. The optimized Cs₂AgInBr₆/Cs₄CuSb₂Cl₁₂ heterojunction has a device efficiency of 31.83 %, which is considerably greater than the power conversion efficiency of 12.91 % for a single layer of Cs₂AgInBr₆. Thus, this study shows that the Cs₂AgInBr₆/Cs₄CuSb₂Cl₁₂ heterojunction PSCs can pave the way for the promising afterward of Cs-based PSCs for real-world uses in optoelectronics and photovoltaics.