Kinetics of Ion-Exchange Reactions in Hybrid Organic-Inorganic Perovskite Thin Films Studied by In Situ Real-Time X-ray Scattering

Alessandro Greco; Alexander Hinderhofer; M Ibrahim Dar; Neha Arora; Jan Hagenlocher; Andrey Chumakov; Michael Grätzel; Frank Schreiber

doi:10.1021/acs.jpclett.8b02916

Kinetics of Ion-Exchange Reactions in Hybrid Organic-Inorganic Perovskite Thin Films Studied by In Situ Real-Time X-ray Scattering

J Phys Chem Lett. 2018 Dec 6;9(23):6750-6754. doi: 10.1021/acs.jpclett.8b02916. Epub 2018 Nov 13.

Authors

Alessandro Greco¹, Alexander Hinderhofer¹, M Ibrahim Dar², Neha Arora², Jan Hagenlocher¹, Andrey Chumakov³, Michael Grätzel², Frank Schreiber¹

Affiliations

¹ Institute for Applied Physics , University of Tübingen , Auf der Morgenstelle 10 , 72076 Tübingen , Germany.
² Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering , École Polytechnique Fédérale de Lausanne , CH-1015 Lausanne , Switzerland.
³ European Synchrotron Radiation Facility , 71, Avenue des Martyrs, CS 40220 , 38043 Grenoble Cedex 9 , France.

PMID: 30400741
DOI: 10.1021/acs.jpclett.8b02916

Abstract

The exchange of ions in hybrid organic-inorganic perovskites with the general formula APbX₃ (A = MA, FA; X = I, Cl, Br) is studied in five different systems using in situ real-time grazing incident X-ray diffraction (GIXD). In systems where the organic cation is exchanged, we find a continuous shift of the lattice parameter. The relative shift compared to the pure materials is used to quantify the exchange. Whether or not a conversion is possible, as well as the amount of exchanged cations, depends on the halide used. In the case of the interconversion of MAPbI₃ and MAPbCl₃, we observe a decay of the diffraction peaks of the original perovskite and the emergence of new peaks corresponding to the structure with the alternative halide. Moreover, we determined the relevant time scales of the growth and decay of the perovskite structures.