title: Transition from the Tetragonal to Cubic Phase of Organohalide Perovskite: The Role of Chlorine in Crystal Formation of CH3NH3PbI3 on TiO2 Substrates.
abstract: The role of chlorine in the superior electronic property and photovoltaic performance of CH3NH3PbI(3-x)Clx perovskite has attracted recent research attention. Here, we study the impact of chlorine in the perspective of the crystal structure of the perovskite layer, which can provide important understanding of its excellent charge mobility and extended lifetimes. In particular, we find that in the presence of chlorine (PbCl2 or CH3NH3Cl), when CH3NH3PbI3 films are deposited on a TiO2 mesoporous layer instead of a planar TiO2 substrate, a stable cubic phase rather than the commonly observed tetragonal phase is formed in CH3NH3PbI3 perovskite at room temperature. The relative peak intensity of two major facets of cubic CH3NH3PbI3 crystals, (100)C and (200)C facets, can also be easily tuned, depending on the film thickness. Furthermore, compared with pristine CH3NH3PbI3 perovskite films, in the presence of chlorine, CH3NH3PbI3 crystals grown on planar substrates exhibit strong preferred orientations on (110)T and (220)T facets.
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Miaoqiang
authors.initials: M
authors.lastname: Lyu
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Yun
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Chen
authors.affiliation: Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland , Brisbane, Queensland 4072, Australia.
authors.forename: Lianzhou
authors.initials: L
authors.lastname: Wang
keywords: CH3NH3PbI3 perovskite; phase transition; tetragonal/cubic phase