title: How the Structures and Properties of Two-Dimensional Layered Perovskites MAPbI3and CsPbI3Vary with the Number of Layers.
abstract: 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 structures of ultrathin (PEA)2PbI4(N) are more flexible and deformable than Cs2PbI4(N). The giant spin-coupling effect greatly decreases the band gaps of both 2D materials; however, it only induces the spin splitting in the bands of (PEA)2PbI4(N). This work suggests that the ultrathin 2D materials can be a potential candidate for nano-optoelectronic devices, and that the nanoplates with N ≥ 3 could have similar performances with bulk materials in the carrier migration and exciton separation so that they can be effectively applied in photovoltaic cells.
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, People's Republic of China.
authors.forename: WanZhen
authors.identifier: http://orcid.org/0000-0002-5931-2901
authors.initials: W
authors.lastname: Liang