CH3NH3PbI3: precise structural consequences of water absorption at ambient conditions

Alla Arakcheeva; Dmitry Chernyshov; Massimo Spina; László Forró; Endre Horváth

doi:10.1107/S2052520616010428

CH₃NH₃PbI₃: precise structural consequences of water absorption at ambient conditions

Acta Crystallogr B Struct Sci Cryst Eng Mater. 2016 Oct 1;72(Pt 5):716-722. doi: 10.1107/S2052520616010428. Epub 2016 Sep 16.

Authors

Alla Arakcheeva¹, Dmitry Chernyshov², Massimo Spina¹, László Forró¹, Endre Horváth¹

Affiliations

¹ Laboratory of Physics of Complex Matter, Ecole polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
² SNBL, ESRF, 71 Avenue des Martyrs, 38043 Grenoble CEDEX 9, France.

PMID: 27698312
DOI: 10.1107/S2052520616010428

Abstract

The crystal structure of the pristine (I) and aged (II) crystals of CH₃NH₃PbI₃ (hereafter MAPbI₃) hybrid organic-inorganic lead iodide has been studied at 293 K with high-precision single-crystal X-ray diffraction using a synchrotron light source. We show that (I) and (II) are characterized by an identical tetragonal unit cell but different space groups: I422 for (I) and P4₂2₁2 for (II). Both space groups are subgroups of I4/mcm, which is widely used for MAPbI₃. The main difference between (I) and (II) comes from the difference in hydrogen bonds between the MA⁺ cation and the PbI₃ framework which is the direct consequence of H₂O insertion in the aged crystal (II).

Keywords: aged MAPbI3; hybrid organic–inorganic lead iodide; hydrogen bonding; perovskite; solar cells.