Effects of Au Nanoparticles Suspended in Chlorobenzene Antisolvent on Mixed-Halide Perovskites

In this work, Au nanoparticles (NPs) were synthesized by laser ablation in liquids (LASiS) by using chlorobenzene, resulting in a stable suspension with a plasmon resonance band around 560 nm. This Au NPs suspension was subsequently used in the antisolvent step for the preparation of the CsFAMA perovskite films. Morphological analyses revealed an increase in the grain size in the Au NPs-modified films, attributed to Au NPs-assisted heterogeneous nucleation. In situ GIWAXS measurements were conducted during film crystallization, pointing out that in the Au NPs-modified films prepared with diluted suspension, the peaks corresponding to the cubic α-phase formed faster and with reduced PbI₂ content, when compared to the control film produced without Au NPs. The characterization of solar cell devices fabricated with Au NPs-modified CsFAMA films presented the influence of the NPs concentration on photovoltaic performance. Devices prepared with diluted Au NPs suspensions exhibited a higher power conversion efficiency (PCE) over time, improved stability, and a reduced hysteresis index.