Aurivillius Halide Perovskite: A New Family of Two-Dimensional Materials for Optoelectronic Applications

Abstract

Layered perovskites have attracted considerable attention in optoelectronic applications due to their excellent electronic properties and stability. In this work, the quasi-2D aurivillius halide perovskites are investigated using density functional theory. The single-layer aurivillius perovskite Ba2PbI6 is predicted to have a direct bandgap of 1.89 eV, which is close to that of the Ruddlesden–Popper perovskite Cs2PbI4. The electronic structures near the Fermi level are mainly governed by the [PbX6] octahedra, which leads to similar electronic properties to that of Cs2PbI4. Decomposition energies reveal that these aurivillius perovskites exhibit thermal instability. Increasing the number of [PbX6] octahedra layer can enhance the stability and reduce the bandgap. Bi- and In-based aurivillius perovskites are also calculated to evaluate the Pb-free alternatives. These calculations can serve as a theoretical support in exploring novel layered perovskites.<br>