Structural optimization of inverted CsPbI₂Br perovskite solar cells for enhanced performance via SCAPS-1D simulation

The CsPbI2Br material benefits perovskite solar cells (PSCs) by balancing their efficiency with chemical and thermal stability. Herein, we performed numerical modeling of a p-i-n structured PSCs employing different electron transport layers (ETLs). In order to optimize the ETL, the simulation results showed bilayer ETL (PCBM/SnO2) yielded the best device performance. Then, by tweaking the absorber layer's defect density, thickness, electron affinity, and band gap, we optimized the device performance utilizing this bilayer ETL and yielded power conversion efficiency (PCE) of 12.51%, fill factor (FF) of 73.60%, open circuit voltage (V ( OC )) of 0.94 V, and short circuit current density (J ( SC )) of 17.94 mA cm(-2). These CsPbI2Br perovskite-based devices would have outstanding thermal stability in a range from 253 K to 323 K. Another important observation in these PSCs is that interfacial defect density plays a crucial for regulating the V ( OC.) We, therefore, anticipate that this research will aid in the development of extremely effective and stable inverted all inorganic PSCs.