Multiple phonon modes in Feynman path-integral variational polaron mobility

Anisotropic Electron–Phonon Interactions in 2D Lead-Halide Perovskites

“…To explain these findings, we turn to the Feynman variational polaron solution of the extended Fröhlich polaron model Hamiltonian. The original Feynman theory explicitly includes multiple phonon modes 70 and anisotropic effective masses. 71 Here, we use the calculated anisotropic modes in the LT phase, associate a Fröhlich dielectric mediated electron–phonon coupling with the infrared activity of each mode, and solve the finite temperature mobility theory for 300 K. We find a Fröhlich dimensionless electron–phonon coupling of 3.44 and 3.75 along the two in-plane lattice vectors; both considerable higher than in 3D halide perovskites.…”