Enhancing efficiency of CIGS solar cell using BSF layer integration technology through numerical simulation

This new study explores cesium tin iodide (CsSnI₃) as a lead-free perovskite BSF layer in CIGS solar cells, utilizing its ideal band alignment and high conductivity to improve charge carrier extraction and diminish recombination losses, ultimately improving photovoltaic performance. The proposed novel device structure (Ni/CsSnI₃/CIGS/ZnS:In/ZnO/Al) has been examined utilizing the SCAPS-1D simulation tool. The solar cell's performance, in the presence and absence of Back surface field (BSF) layer is assessed by adjusting several factors for optimizing the device performance. Under the AM 1.5 G spectrum, and considering series resistance of 0.5 Ω-cm² and shunt resistance of 10⁷ Ω-cm² to maintain the realistic condition for simulation of the device structure. Aluminium and nickel are taken as front and rear contact electrode material with work functions of 4.2 eV and 5.15 eV respectively. The newly suggested passivated solar cell designs give an efficiency of 27.66%, with V_OC of 0.78 V, J_SC of 43.02 mA cm⁻², and FF of 81.80%. The designed solar cell integrated with perovskite BSF layer cesium tin iodide (CsSnI₃) performs better than the traditional CIGS solar cell design and opens up new avenues for cutting-edge solar cell research. The authors calibrated CIGS solar cells with experimental data before designing and simulating a new structure to ensure accurate simulation results. This research offers valuable insights for manufacturers aiming to produce cost-effective CIGS solar cells. Furthermore, the proposed device structure demonstrates strong potential for future advancements in tandem solar cell applications.