Optimizing key parameters to enhance the performance of lead-free perovskite solar cells with a Cs2AgBiCl6 absorber layer using SCAPS-1D simulation

Lead-free double perovskites, characterized by the general formula A2BIBIIIX6, present a promising alternative to address the instability and toxicity issues associated with lead halide perovskite solar cells. Nevertheless, the advancement of lead-free perovskite solar cells is hindered by several challenges. Despite these obstacles, optimizing various parameters can facilitate the development of lead-free perovskite solar cells. The performance of perovskite solar cells (PSCs) is influenced by a range of internal and external factors, including the thickness of the perovskite layer, the electron transport layer (ETL), the hole transport layer (HTL), defect density at layers and interfaces, operating temperature, shunt resistance (Rsh), and series resistance (Rs). This study utilizes SCAPS-1D software to simulate and optimize these parameters in lead-free perovskite solar cells featuring a Cs2AgBiCl6 absorber layer. Through extensive numerical simulations, we observed notable enhancements in critical performance indicators such as open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE), while effectively minimizing recombination losses. Our results indicate that increasing the thickness of the perovskite layer improves light absorption and JSC; however, excessive thickness can lead to recombination losses, adversely affecting VOC, FF, and overall PCE. We identified optimal thicknesses for the ETL and HTL that strike a balance between charge extraction efficiency and resistive losses. Additionally, reducing defect densities across all layers significantly boosts PCE by limiting recombination pathways. Effective temperature management, along with the reduction of series resistance and enhancement of shunt resistance, is crucial for improving PCE.