title: Engineering of CH3 NH3 PbI3 Perovskite Crystals by Alloying Large Organic Cations for Enhanced Thermal Stability and Transport Properties.
abstract: The number of studies on organic-inorganic hybrid perovskites has soared in recent years. However, the majority of hybrid perovskites under investigation are based on a limited number of organic cations of suitable sizes, such as methylammonium and formamidinium. These small cations easily fit into the perovskite's three-dimensional (3D) lead halide framework to produce semiconductors with excellent charge transport properties. Until now, larger cations, such as ethylammonium, have been found to form 2D crystals with lead halide. Here we show for the first time that ethylammonium can in fact be incorporated coordinately with methylammonium in the lattice of a 3D perovskite thanks to a balance of opposite lattice distortion strains. This inclusion results in higher crystal symmetry, improved material stability, and markedly enhanced charge carrier lifetime. This crystal engineering strategy of balancing opposite lattice distortion effects vastly increases the number of potential choices of organic cations for 3D perovskites, opening up new degrees of freedom to tailor their optoelectronic and environmental properties.
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Wei
authors.initials: W
authors.lastname: Peng
authors.affiliation: Imaging and Characterization Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Xiaohe
authors.initials: X
authors.lastname: Miao
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, M5S 3G4, Canada.
authors.forename: Valerio
authors.initials: V
authors.lastname: Adinolfi
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Erkki
authors.initials: E
authors.lastname: Alarousu
authors.affiliation: Analytical Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Omar
authors.initials: O
authors.lastname: El Tall
authors.affiliation: Imaging and Characterization Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Abdul-Hamid
authors.initials: AH
authors.lastname: Emwas
authors.affiliation: Imaging and Characterization Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, M5S 3G4, Canada.
authors.forename: Grant
authors.initials: G
authors.lastname: Walters
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Jiakai
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, M5S 3G4, Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Ouellette
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Jun
authors.initials: J
authors.lastname: Pan
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Banavoth
authors.initials: B
authors.lastname: Murali
authors.affiliation: Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, M5S 3G4, Canada.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Sargent
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Omar F
authors.initials: OF
authors.lastname: Mohammed
authors.affiliation: Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia. osman.bakr@kaust.edu.sa.
authors.forename: Osman M
authors.initials: OM
authors.lastname: Bakr
keywords: crystal engineering; organic-inorganic hybrid composites; perovskite phases; photovoltaics