Control of Crystal Symmetry Breaking with Halogen-Substituted Benzylammonium in Layered Hybrid Metal-Halide Perovskites.
J Am Chem Soc
; 142(11): 5060-5067, 2020 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-32101409
ABSTRACT
Layered hybrid metal-halide perovskites with non-centrosymmetric crystal structure are predicted to show spin-selective band splitting from Rashba effects. Thus, fabrication of metal-halide perovskites with defined crystal symmetry is desired to control the spin-splitting in their electronic states. Here, we report the influence of halogen para-substituents on the crystal structure of benzylammonium lead iodide perovskites (4-XC6H4CH2NH3)2PbI4 (X = H, F, Cl, Br). Using X-ray diffraction and second-harmonic generation, we study structure and symmetry of single-crystal and thin-film samples. We report that introduction of a halogen atom lowers the crystal symmetry such that the chlorine- and bromine-substituted structures are non-centrosymmetric. The differences can be attributed to the nature of the intermolecular interactions between the organic molecules. We calculate electronic band structures and find good control of Rashba splittings. Our results present a facile approach to tailor hybrid layered metal halide perovskites with potential for spintronic and nonlinear optical applications.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Reino Unido