Influence of Anti-Solvents on the Performance of Cesium Bismuth Iodide Perovskite Solar Cells

In this paper, the influence of anti-solvents on the properties of cesium bismuth iodide (CBI – Cs 3 Bi 2 I 9 ) perovskite solar cells (PeSCs) that were dripped with different anti-solvents, i.e., isopropanol, chlorobenzene (CB), and toluene during the spin-coating process was evaluated. Scanning electron microscopy images visually depicted the presence of extremely flat and homogeneous film with highly compactness for the Cs 3 Bi 2 I 9 fabricated with isopropanol compared to other anti-solvents. A strong absorption band was observed at around the wavelength of 500 nm for all the CBI films, and we found that the maximum absorption percentage reached as high as 85%, while the current-voltage measurement showed that the CBI film fabricated with isopropanol showed twenty-one times increment than CB, in terms of power conversion efficiency and short circuit current density. Our findings suggest a further improvement of CBI film morphology by the anti-solvent for enhanced morphology and better solar cell performance in the future.