Twinning in MAPbI3 at room temperature uncovered through Laue neutron diffraction

Joachim Breternitz,Susan Schorr,Michael Tovar

doi:10.1038/s41598-020-73487-1

Joachim Breternitz, Susan Schorr + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-73487-1

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Abstract

The crystal structure of MAPbI3, the signature compound of the hybrid halide perovskites, at room temperature has been a reason for debate and confusion in the past. Part of this confusion may be due to twinning as the material bears a phase transition just above room temperature, which follows a direct group–subgroup relationship and is prone to twinning. Using neutron Laue diffraction, we illustrate the nature of twinning in the room temperature structure of MAPbI3 and explain its origins from a group-theoretical point-of-view.

Highlights

The crystal structure of M APbI3, the signature compound of the hybrid halide perovskites, at room temperature has been a reason for debate and confusion in the past
While the rise in efficiency has provoked a huge interest in applied research—with some 4000 papers published on halide perovskites in 2 0194, the efforts in structural elucidation have not always been commensurate
In the case of MAPbI3 at room temperature, this would correspond to inversion twins in this case, as the inversion symmetry is lost between I4/mcm and I4cm

Summary

Introduction

The crystal structure of M APbI3, the signature compound of the hybrid halide perovskites, at room temperature has been a reason for debate and confusion in the past. Part of this confusion may be due to twinning as the material bears a phase transition just above room temperature, which follows a direct group–subgroup relationship and is prone to twinning. One important factor in the structural elucidation of hybrid halide perovskites in general[20,22] and MAPbI3 in particular[23,24,25,26] is their tendency for twinning This twinning can be associated with the phase transition from the high-temperature phase in the cubic aristotype to the lower temperature hettotypes. We studied a crystal that was synthesised at room

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Conclusion