Device modelling and numerical analysis of high-efficiency double absorbers solar cells with diverse transport layer materials

Recently, a lot of focus has been placed on cesium lead iodide (CsPbI₃) since it is considered a potentially useful inorganic halide perovskite with improved stability. Moreover, another potential absorber material is the mixed chalcogenide CZTSSe, which is abundant on Earth, cheap, environmentally acceptable, and has excellent photovoltaic performance. This research numerically simulated a novel double absorber solar cell structure employing CsPbI₃ and CZTSSe absorbers in the active layer in SCAPS-1D. The current study analyses the effects of various electron and hole transport materials, back contact material's work functions, working temperatures, variations in defect concentration, and absorber thickness on the performance of photovoltaic devices. After researching a variety of distinct arrangements of double absorber solar cells, it was realized that the FTO/STO/CsPbI₃/CZTSSe/NiO/W cell configuration exhibited the best overall performance with an open circuit voltage (V_oc) at 1.0207 V, a short circuit current density (J_sc) at 41.815426 mA/cm², Fill Factor (FF) at 87.50 %, and a Power Conversion Efficiency (PCE) at 37.35 %. The modeling of the device showed that a thickness of around 1.4 µm for the CZTSSe absorber is optimal. This simulation shows that when the working temperature in the cell and the defect concentration in the absorber increase, the efficiency of the device reduces uniformly, and the device is stable at 300 K temperature. In conclusion, if the material's work function is greater than 5.20 eV, then it is suitable for use as an anode.