Numerical Simulation Analysis of Two-Terminal Monolithic Perovskite-CIGS Tandem Solar Cell for Enhanced Photovoltaic...

This research designs and simulates a high-efficiency tandem solar cell (TSC) using SCAPS-1D (3.3.12), exploiting tandem perovskite technology for enhanced performance. The agenda of our work is here to minimize the two largest losses associated with single-junction solar cells like thermalization and transmission losses by absorbing a broader spectrum of sunlight using CsGeI₃/CIGS tandem solar cell technology. To ensure the accuracy of the simulated results, the authors first calibrate both the top and bottom solar cells using experimental data and compare the simulated results with experimental findings. This study investigates the impact of thickness, parasitic resistance, temperature, quantum efficiency, band diagram, absorption coefficients, and two-diode model equivalent circuit parameters on solar cell performance. This work optimizes lead-free, wide bandgap (1.6 eV) CsGeI₃ perovskite and narrow bandgap (1.1 eV) CIGS solar cells individually and then proposes a tandem solar cell structure using a filtered spectrum approach. The proposed CsGeI₃/CIGS tandem solar cell device structure is studied in detail and simulated using SCAPS 1D. A tandem configuration, with a thickness of a 273 nm top cell (simulated under AM1.5G) and a 1000 nm bottom cell, achieved conversion efficiencies of 16.93% and 16.49%, respectively, with respective J_SC values of 19.31 mA cm^-2/19.32 mA cm^-2. By adding the voltages at same current points to make the tandem J-V curve, this design yielded a 26.06% efficient perovskite-CIGS tandem cell with V_OC of 1.73 V, J_SC of 19.32 mA cm^-2, and FF of 77.98%. This perovskite-CIGS tandem design demonstrates a promising route for developing high-efficiency, low-cost TSCs.