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

Layered perovskites have attracted considerable attention in optoelectronic applications because of 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 band gap 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 electronic properties similar to that of Cs2PbI4. Decomposition energies reveal that these Aurivillius perovskites exhibit thermal instability. However, increasing the number of the [PbX6] octahedra layer can enhance the stability and reduce the band gap. Our results indicated that for n ≥ 5, it is possible to synthesize the thermally stable Cl-based Aurivillius perovskite Ba2Csn-1PbnCl3n+3. 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 for optoelectronic applications.