The influence of deuteration on the crystal structure of hybrid halide perovskites: a temperature-dependent neutron diffraction study of FAPbBr<sub>3</sub>
Alexandra Franz, Daniel M. Többens, Frederike Lehmann, M. Kärgell, Susan Schorr
Abstract
This paper discusses the full structural solution of the hybrid perovskite formamidinium lead tribromide (FAPbBr 3 ) and its temperature-dependent phase transitions in the range from 3 K to 300 K using neutron powder diffraction and synchrotron X-ray diffraction. Special emphasis is put on the influence of deuteration on formamidinium, its position in the unit cell and disordering in comparison to fully hydrogenated FAPbBr 3 . The temperature-dependent measurements show that deuteration critically influences the crystal structures, i.e. results in partially-ordered temperature-dependent structural modifications in which two symmetry-independent molecule positions with additional dislocation of the molecular centre atom and molecular angle inclinations are present.