Design, optimization and enhancement of power conversion efficiency exceeding 30% for lead-free all-inorganic double perovskite-based solar cells using dual active layers

Abstract

Here, we present a comprehensive simulation study focused on the design and optimization of power conversion efficiency (η) for lead-free, all-inorganic double perovskite-based solar cell (DPSC) device using SCAPS 1D. A non-toxic halide double perovskite layer, Cs2AgSb0.25Bi0.75Br6 is employed as absorber layer in designed solar cell along with various electron transport layers like ZnO, TiO2, C60, PCBM, IGZO and hole transport layers including NiO, Cu2O, MoO3, CuI, spiro-OMeTAD in n-i-p heterostructure configuration, aiming to achieve eco-friendly device with optimized efficiency and enhanced stability. The optimal configuration, FTO/C60/ Cs2AgSb0.25Bi0.75Br6/Cu2O/C, achieves a η ∼ 25.32% with Voc ∼ 1.58 V, Jsc ∼ 17.48 mA/cm2 and FF ∼ 91.4%. To further enhance the device performance, double active layers combining CsSnCl3 (band gap ∼ 1.52 eV) and Cs2AgSb0.25Bi0.75Br6 (band gap ∼ 1.80 eV) are introduced into the optimized device to leverage optical absorption for wide range of solar spectrum due to the graded optical band gap. Consequently, the power conversion efficiency of the cell elevated to ∼ 32.23% accompanied by Voc ∼ 1.36 V, Jsc ∼ 26.34 mA/cm2 and FF ∼ 90.3%, with a promise of creating high-efficiency solar cell devices, driving substantial progress in green energy technology.