Controlling Secondary Crystallization with 1-Butanol for High-Efficiency Perovskite Solar Cells.

Regulating nucleation and crystallization is crucial for achieving high-quality, pinhole-free, and defect-minimized perovskite films for efficient solar devices. This study explores the impact of alcoholic anti-solvents as eco-friendly alternatives to the commonly used chlorobenzene (CB) on the optoelectronic properties of perovskite films, including crystallization, film quality, and defect density in perovskite films. Our findings show that 1-butanol (BuOH) is the most effective, promoting both primary and secondary crystallization, reducing defects, and enhancing film quality. Time-dependent studies indicate that shorter BuOH application times improves crystalline growth, albeit with some impact on surface morphology. A champion power conversion efficiency (PCE) of 25.45% along with an open-circuit voltage (VOC) of 1.223 V is achieved in perovskite solar cells with a bandgap of 1.59 eV, highlighting the potential of alcoholic anti-solvents for enhancing performance and offering a sustainable, scalable solution for high-efficiency device fabrication.