Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors

Layered halide hybrid organic-inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells and revisited for light-emitting devices. In this review, we combine classical solid-state physics concepts with simulation tools based on density functional theory to overview the main features of the optoelectronic properties of layered HOP. A detailed comparison between layered and 3D HOP is performed to highlight differences and similarities. In the same way as the cubic phase was established for 3D HOP, here we introduce the tetragonal phase with D symmetry as the reference phase for 2D monolayered HOP. It allows for detailed analysis of the spin-orbit coupling effects and structural transitions with corresponding electronic band folding. We further investigate the effects of octahedral tilting on the band gap, loss of inversion symmetry and possible Rashba effect, quantum confinement, and dielectric confinement related to the organic barrier, up to excitonic properties. Altogether, this paper aims to provide an interpretive and predictive framework for 3D and 2D layered HOP optoelectronic properties.
The work at FOTON is supported by Agence Nationale pour la Recherche (SNAP and SuperSansPlomb projects) and was performed using HPC resources from GENCI-CINES/IDRIS Grant 2016-c2012096724. The work at ISCR is supported by Agence Nationale pour la Recherche (TRANSHYPERO project). J.E.’s work is supported by the Fondation d’entreprises banque Populaire de l’Ouest under Grant PEROPHOT 2015. The work at Los Alamos National Laboratory (LANL) was supported by LANL LDRD program and was partially performed at the Center for Nonlinear Studies and at the Center for Integrated Nanotechnologies, a U.S. Department of Energy, Office of Science user facility. The Groningen team would like to acknowledge funding from European Research Council (ERC Starting Grant “Hy-SPOD” No. 306983) and by the Foundation for Fundamental Research on Matter (FOM), which is part of The Netherlands Organization for Scientific Research (NWO), under the framework of the FOM Focus Group “Next Generation Organic Photovoltaics”. ICN2 acknowledges support from the Severo Ochoa Program (MINECO, Grant SEV-2013-0295). This project received funding from the European Union's Horizon 2020 research and innovation programme under the grant agreement no. 687008.