Multiscale calculation of carrier mobility in organic solids through the fine-tuned kinetic Monte Carlo simulation

A multiscale approach is proposed to calculate carrier mobility (μ) in organic solids, bridging the molecular-level simulations and the kinetic Monte Carlo (kMC) method. The amorphous molecular supercell was prepared by the molecular dynamic simulation, then the density functional calculations were performed to obtain the relevant parameters for Marcus charge transfer between the constituent molecules. The on-lattice type kMC simulation implementing the Marcus transfer is systematically tuned to best mimic the profile of carrier transport in the simulated molecular supercell. The calculated μ readily reproduced the Pool-Frenkel field dependency, indicating that the present work well represents the typical behavior of carrier transport in organic systems. It is also shown that the calculation results of 4 anthracene-derivatives and 6 hole-transporting molecules agree well with the time-of-flight measurements from literature, while requiring the modest calculation cost in comparison with the similar calculations introduced elsewhere.