Proceedings of nanoGe Spring Meeting 2022 (NSM22)
DOI: https://doi.org/10.29363/nanoge.nsm.2022.126
Publication date: 7th February 2022
Two-dimensional (2D) hybrid organic−inorganic perovskites are attracting interest thanks to their wide range of applications for solar energy conversion and beyond. Among their advantages, the tunability of their structural and optical properties is unique. For example, as the structural features of the organic spacers vary, the distancing between the inorganic layers can be affected – which affects the quantum confinement and hence the bandgap of the 2D perovskite. To experimentally elucidate the effect of the organic spacer on the optical and structural properties of perovskites, we applied hydrostatic pressures up to 375 MPa onto 2D materials with different spacers - e.g. butylammonium, benzylammonium, phenylehtylammonium, naphthalene-O-propylammonium, and perylene-O-ehtylammonium. In addition to a different degree of rigidity and extent of bandgap shift of the 2D materials for different spacers, we found that when butylammonium is used as the spacer, the 2D material undergoes a first-order phase transition at 350 MPa. By studying the specific effect of aromaticity and alkyl chain length of the organic spacers on the overall rigidity (hence, bandgap shift) of the 2D material and finding a pressure-dependent phase transition in one of the studied materials, our work is essential to designing 2D perovskites with finely tuned optical and structural properties.