High-Efficiency Double-Heterojunction Based Dual-Absorber Perovskite Solar Cell via Numerical Optimization

In this study, a novel double-heterojunction perovskite solar cell (DHPSC) with the following structure: FTO/ZnO/CH3NH3PbI3−xClx/CH3NH3SnI3/p++ZnTe/Au was designed. It was optimized using the wxAMPS simulation software. A systematic parametric analysis was performed to investigate the influence of electron transport layer (ETL) ZnO and hole transport layer (HTL) thicknesses on photovoltaic performance. That includes short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (η). The results indicate that once a minimum ZnO thickness is achieved, further increases have a negligible effect on performance. Whereas variations in ZnTe thickness markedly influence Voc and η. The optimal configuration obtained, comprising a FTO (200 nm)/ZnO (600 nm)/CH3NH3PbI3−xClx (800 nm)/CH3NH3SnI3 (800 nm)/ZnTe (350 nm), achieved a Voc of 1.996 V, Jsc of 20.61 mA/cm2, FF of 93.11%, and 38.24%. Quantum efficiency analysis revealed superior spectral response, exceeding 95% across the visible spectrum. These findings demonstrate the potential of a thickness-optimized DHPSC device for achieving high performance, providing a pathway for future experimental validation and fabrication.