Improving Charge Transport in Perovskite Solar Cells Using Solvent Additive Technique

Perovskite solar cells (PSCs) have demonstrated remarkable progress in performance in recent years, which has placed perovskite materials as the leading promising materials for future renewable energy applications. The solvent additive technique in perovskite composition is a simple but effective process used to improve the surface quality of the perovskite layers and to improve the performance and charge transport processes essential to the functions of PSCs. These additives can have a considerable effect on the topography, crystallinity, and surface properties of the perovskite active layer, ultimately influencing the stability of the PSCs. A “two-step spin coating” deposition method to make PSCs in ambient air laboratory conditions was employed. Acetonitrile (ACN) was conventionally utilized as a chemical additive to enhance the performance of PSCs. In this study, our film properties exhibited that the incorporation of ACN in the triple cation perovskite precursor led to the passivation of surface defects and a noticeable increase in the size of the crystal grains of the perovskite films, which led to enhanced stability of devices. The efficiency achieved for PSCs prepared with 10% ACN was 15.35%, which is 30% higher than devices prepared without ACN. In addition, devices prepared with ACN have shown a lower hysteresis index and more stable behavior compared to devices prepared without ACN. This work presents an easy, low-cost method for the fabrication of high performance PSCs prepared under ambient air laboratory conditions.