Development of a Classical Interatomic Potential for MAPbBr(3)

作者：Hata Tomoyuki; Giorgi Giacomo; Yamashita Koichi; Caddeo Claudia; Mattoni Alessandro

来源：Journal of Physical Chemistry C, 2017, 121(7): 3724-3733.

DOI：10.1021/acs.jpcc.6b11298

We develop a classical interatomic potential for MAPbBr(3). The model belongs to the class of MYP force-fields for hybrid perovskites based on two-body Buckhingam-Coulomb and dispersive terms to describe organic inorganic interactions and already successfully applied to MAPbI(3). The model calibration is based on a simplified procedure able to extend one existing parametrization to a different halide by suitable scaling of selected subgroups of parameters. The main static and dynamical properties of MAPbBr(3) are well reproduced by the developed model: the lattice constant, cohesive energy curve, bulk modulus, energy barriers for cation rotations (both static and dynamic), the phase transition temperatures, and structural parameters evolution with temperature. The model also provides a valid relationship between MAPbBr(3) and MAPbI(3): MAPbBr(3) has shorter lattice constant, higher cohesive energy, lower phase transition temperatures, and larger anisotropy in orthorhombic phase. The good comparison also extends to the vibrational properties at finite temperatures that have been benchmarked on experimental and DFT results. The developed MAPbBr(3) model is further used to calculate the MA dynamics in MAPbBr(3) at room temperature finding a reorientation time of similar to 3ps in good agreement with experimental data. Present work represents an important step toward the large-scale atomistic modeling of MAPbBr(3) and the development of a general class of force fields for hybrid perovskites.

• 出版日期2017-2-23