SCAPS-1D Simulation of Various Hole Transport Layers' Impact on CsPbI₂Br Perovskite Solar Cells Under Indoor Low-Light Conditions

This study utilized SCAPS-1D solar simulation software to model how different hole transport layers (HTLs) affect the photoelectric conversion efficiency (PCE) of CsPbI₂Br perovskite solar cells under indoor low-light conditions. Simulation parameters include 300 K working temperature, white LED light source with 560 lux illuminance, 5700 K color temperature, equivalent to 0.661 mW/cm² power density. The investigation explores the influence of layer thickness and defect concentration on performance to identify optimal parameters. Simulation results revealed that among eight hole transport materials (CuSCN, Cu₂O, CuI, NiO, MoS₂, PTAA, P3HT, Spiro-OMeTAD), CuI achieved the best performance with open-circuit voltage (Voc) of 1.22 V, short-circuit current density (Jsc) of 0.153 mA/cm², fill factor (FF) of 83.84%, and PCE of 23.66%. Analysis of HTL and absorption layer thickness, bulk defect concentration, interface defect density, and HTL-free scenario showed that interface defect concentration and absorption layer parameters have greater influence than HTL thickness. Under optimized conditions of 0.87 μm absorption layer thickness, defect concentration of 10¹⁵ cm⁻³, and interface defect concentration of 10⁹ cm⁻³, PCE reached 26.13%, while the HTL-free structure achieved 19.57%. This study demonstrates that CuI as HTL provides excellent efficiency for CsPbI₂Br perovskite solar cells and highlights their potential in indoor low-light power generation applications.