Microscopic theory of Raman scattering for the rotational organic cation in metal halide perovskites

Abstract

A gap exists in microscopic understanding the dynamic properties of the rotational organic cation (ROC) in the inorganic framework of the metal halide perovskites (MHP) to date. Herein, we develop a microscopic theory of Raman scattering for the ROC in MHP based on the angular momentum of a ROC exchanging with that of the photon and phonon. We systematically present the selection rules for the angular momentum transfer among three lowest rotational levels. We find that the phonon angular momentum that arising from the inorganic framework and its specific values could be directly manifested by Stokes (or anti-Stokes) shift. Moreover, the initial orientation of the ROC and its preferentially rotational directions could be judged in Raman spectra. This study lays the theoretical foundation for the high-precision resolution and manipulation of molecular rotation immersed in many-body environment by Raman technique.

Rotor Lattice Model of Ferroelectric Large Polarons

“…In addition, studies that connect the abstract model parameters with realistic material properties will be crucial. The possibility of angulon formation affecting molecular mobility [52][53][54][55][56] and of the halogen-metal hybridization modifying the molecule-carrier interaction [57,58] might also be relevant for reliable modeling of HOIP properties with rotor lattice setups.…”