Maneuvering into Postsynthetic Solvent Interaction in PEA-Based Perovskites

Organic–inorganic hybrid perovskites (OIHPs) have a variety of optoelectronic applications owing to their remarkable stability, resistance to moisture, ease of production, and fascinating photophysical characteristics. Despite prior literature studies suggesting that the solvent plays a vital role in controlling the crystallinity of OIHPs, it is unclear how the solvent features, like dielectric effects, solvent polarity, hydrogen-bonding (H-bonding) ability, etc., affect the optoelectronic properties of these materials. We delve into the structural and photophysical characteristics of layered 2D lead-halide perovskites, the phenyl ethylammonium-lead bromide perovskite (PEBP), with a collection of postsynthetic solvent treatments. Using an array of solvents with diverse polarities, we highlight different structural changes of the OIHP by both structural and spectroscopic measurements. While the nonpolar solvents with a low dielectric and weak H-bonding ability assist in maintaining the crystal structure and improving the crystallite sizes, the solvents with a high dielectric constant and hydrogen bond acceptor ability do the reversal. The high-polarity solvents causing aggregation to the crystallites are due to strong H-bonding interactions between the solvent molecules and the positively charged phenyl-ethylammonium ion, which is also responsible for the quenching of photoluminescence of the material. Therefore, our findings emphasize the importance of intra- and intermolecular interactions present in layered OIHPs, which drive the material’s stability in various organic solvents for future use in device applications.