How the Structures and Properties of Two-Dimensional Layered Perovskites MAPbI₃ and CsPbI₃ Vary with the Number of Layers

This work aims to explore the intrinsic properties of two-dimensional (2D)-layered perovskites, (PEA)2PbI4(N) and Cs2PbI4(N), and demonstrating how their structures and properties vary with N. The results reveal that both (PEA)2PbI4(N) and Cs2PbI4(N) are direct bandgap semiconductors, their band/optical gaps and exciton-binding energies vary linearly with 1/N at N ≥ 3, and the effective masses slowly vary with N. Compared to the bulk phases, the...