Design insights into eco-friendly K2TiI6/MASnI3 perovskite-based tandem solar cell

Perovskite materials have gained significant attention due to their exceptional optical and electronic properties, which have transformed solar cell technology. In addition, their high light absorption capacity, long carrier mobility, tunable bandgap, and affordable cost of production make perovskites desirable as ideal materials for solar cell technology. In this article, a double-absorber-based solar cell is designed and optimized using SCAPS-1D solar simulation software. The study used K₂TiI₆ and MASnI₃ organic-inorganic perovskite as the top and bottom adsorber layers, respectively. The primary objective of this research is to evaluate the compatible components for the electron-transporting layers (ETL) and hole-transporting layers (HTL). Also, this research aims to determine optimal values for active layer thickness, temperature, absorbing defect density, and metal work functions to enhance photovoltaic cell performance. Upon optimizing the proposed solar cell architecture by changing various elements in the ETL and HTL, the optimal configuration has achieved the FTO/TiO₂/K₂TiI₆/MASnI₃/Cu₂O/W structure, which demonstrates an open circuit voltage of V_oc = 1.138 V, a fill factor (FF) of 82.38 %, a short-circuit current of J_sc = 34.834 mA/cm², and a maximum power conversion efficiency (PCE) of 32.67 %. Progress is achieved by utilizing TiO₂ as the ETL and Cu₂O as the HTL in the configuration when the thickness of the MASnI₃ absorber was set at 1 μm, the K₂TiI₆ absorber was at 0.15 μm, and back contact metal W (5.22eV). The light and flexible structure of K₂TiI₆ and MASnI₃ perovskite makes it promising for next-generation photovoltaic technology. This model of current silicon and lead-based photovoltaic technologies can be an alternative, making solar energy use more accessible and efficient.