Rotor Lattice Model of Ferroelectric Large Polarons

Abstract

We present a minimal model of charge transport in hybrid perovskites, which provides an intuitive explanation for the recently proposed formation of ferroelectric large polarons. We demonstrate that short-ranged charge--rotor interactions lead to long-range ferroelectic ordering of rotors, which strongly affects the carrier mobility. In the nonperturbative regime, where our theory cannot be reduced to any of the earlier models, we predict polaron properties in good agreement with experiment. This shows the potential of simple models to reveal electronic properties of molecular materials.