Multifunctional Dye Interlayer Enhances the Power Conversion Efficiency of Cs2AgBiBr6 Lead-Free Inorganic Perovskite Solar Cell in a SCAPS-1D Simulation

This study presents a simple, yet efficient method for improving the performance of Cs2AgBiBr6 perovskite solar cells (PSCs) by adding a N719 dye as an interlayer between the absorber and the hole transport layer (HTL). This was achieved through device simulation using solar capacitance simulation software in one dimension (SCAPS-1D), which based on Poisson and continuity equations. The presence of the N719 dye promotes faster hole extraction, improves energy level alignment within the device structure, decreases charge carrier recombination, and increases the range of light absorption. The open circuit voltage (Voc), current density (Jsc), fill factor (FF), and power conversion efficiency (PCE) of the pure Cs2AgBiBr6-based device were 0.81V, 7.61 mA/cm2, 46.68%, and 2.89%, respectively, whereas the Voc, Jsc, FF, and PCE of the N719 modified Cs2AgBiBr6 device were 1.15 V, 8.05 mA/cm2, 59.89%, and 5.53% respectively. Consequently, optimizing the electron transport layer (ETL) ND, ETL Nt, absorber layer band gap, thickness, and absorber Nt, to obtain the optimal values of 1020 cm-3, 1015 cm-2, 1.9 eV, 0.4 μm, and 1011 cm-2, respectively, led to achieve a remarkable PCE of 14.09%, which is a notable improvement over the Cs2AgBiBr6-based perovskite solar cells that have been previously documented in the literature.