Abstract : Hybrid organic-inorganic perovskites have become one of the most promising low-cost alternatives to traditional semiconductors in the field of photovoltaics and light emitting devices. It combines both attractive features of organic and inorganic materials within a single composite, for instance with excellent electronic properties. We used x-ray diffraction to reveal a sub-structure within CH 3 NH 3 PbI 3 single crystals. We could observe the presence of additional peaks with a square symmetry in several monocrystalline samples. We discuss these results in terms of two different models: a superstructure modulated in two in-plane orthogonal directions, and a model with tilted domains with a shallow angle of ~0.6°. In both cases, the modulated or tilted domains appear in regions with small lattice expansion. We show that this last model appears to be the most likely to explain our observations.
V.L.R. Jacques 1 A Gallo-Frantz 1 Antonio Tejeda 1 D Le Bolloc’h 1 Ferdinand Lédée 2 Gaëlle Trippé-Allard 2 Damien Garrot 3 Pierre Fertey 4 Emmanuelle Deleporte 2 Olivier Plantevin 5
1 LPS – Laboratoire de Physique des Solides
2 LAC – Laboratoire Aimé Cotton
3 GEMAC – Groupe d’Etude de la Matière Condensée
4 SSOLEIL – Synchrotron SOLEIL
5 CSNSM – Centre de Sciences Nucléaires et de Sciences de la Matière
