We implement a simple, continuous, analytical model for exciton hopping in an energetically disordered molecular landscape. The model is parameterized against atomistic and lattice Monte Carlo simulations based on quantum-chemical calculations. It captures the essential physics of exciton diffusion in disordered media at different temperatures and yields a universal scaling law of the diffusion length with the dimensionless disorder parameter given by the ratio of the energetic disorder width to the thermal energy.
Athanasopoulos, S., Emelianova, E. V., Walker, A. B., & Beljonne, D. (2009). Exciton diffusion in energetically disordered organic materials. Physical Review B, 80(19), . https://doi.org/10.1103/PhysRevB.80.195209