Device optimization of CsPbI2Br-based inorganic perovskite solar cells using different charge transport layers via SCAPS-1D

Perovskite solar cells (PSCs) have attracted considerable attention due to their high-power conversion efficiency (PCE) of more than 26 % in recent years. They can be produced at lowcost, and on flexible substrates. They have tunable bandgap making them suitable for a range of applications. However, the thermal instability of these devices is still a challenge for their commercialization. Recently, all-inorganic PSCs based on CsPbI2Br emerged as a new potential candidate for photovoltaic applications due to their long-term thermal stability. Solar Cell Capacitance Simulator (SCAPS-1D) software can be used to simulate and analyze the performance of perovskite solar cells. It can be used to study device modeling, solar cell parameter extraction, device optimization, and its comparison with experimental data. Here we have used SCAPS-1D to analyze the device parameters of inorganic perovskite solar cells (n-i-p configuration) with varying hole transport layers (HTLs) and electron transport layers (ETLs). Initially, different HTLs such as CuI, Cu2O, CuSCN, and MoOx are employed keeping ETL (TiO2) and the absorber layer (CsPbI2Br) fixed. The highest performance is obtained for devices containing CuSCN as HTL. Furthermore, device performance is further checked by varying the ETL such as ZnO, WS2, and SnO2 keeping HTL (CuSCN) and absorber layer (CsPbI2Br) constant. The results showed that the device with configuration FTO/TiO2/CsPbI2Br/CuSCN/Fe shows better performance. In addition, for each device configuration, the effect of the charge transport layer's thickness, the effect of absorber layer thickness, band gap, and defect density on the performance of the device has also been studied to obtain the best device performance. The thickness of the charge transport layers, and the absorber layer greatly affect the transport of photo-generated charges within the device. The highest power conversion efficiency (PCE) obtained for n-i-p configuration with TiO2 (10 nm), CuSCN (30 nm) and absorber layer CsPbI2Br (520 nm) is 14.66 %.The corresponding fill factor (FF) for the given configuration is 76.57 %, with short circuit current density (JSC) of 16.4 mA/cm2, and open circuit voltage (VOC) of 1.16 V. We hope our findings will contribute to understanding the Perovskite solar cells (PSCs) structure with different hole transport layers, and ultimately lead to the development of more efficient, stable, and cost-effective perovskite solar cells for commercial applications.