Used in perovskite solar cells as a key additive to improve device efficiency and stability. It helps in forming two-dimensional (2D) perovskite layers on the surface of 3D perovskite films, which enhances moisture resistance and reduces defect density. This chemical passivates grain boundaries and interfaces, leading to better charge transport and reduced recombination. It is also explored in optoelectronic devices for bandgap tuning and improving film morphology during fabrication.