Exciton–phonon coupling in alanine-based hybrid lead bromide

Abstract

Recently, hybrid metal–halide perovskite-like compounds have emerged as promising materials for optoelectronic applications. Such materials show optical properties that are usually tunable by the so-called perovskite dimensionality as well as octahedral distortion and connectivity. In this study, we have investigated the optical properties of an alanine-based 2D hybrid lead bromide with simultaneous edge- and corner-sharing [PbBr₆]⁴⁻ octahedra. This compound has a large bandgap of 3.62 eV and broad photoluminescence, which are correlated through structural properties. Also, we showed that this emission exhibits a CCT of 3385 K corresponding to the “warm” white light emission characteristic of self-trapped exciton formation. Finally, we showed that the strong exciton–phonon interaction is the main mechanism of photoluminescence broadening.