Modeling of hole transport across grain boundaries in organic semiconductors for mesoscale simulations

Mesoscale carrier transport simulations for organic semiconductors with heterogeneous polycrystalline structures are very challenging because the charge transfer rates across the grain boundaries are unknown. To overcome this difficulty, we studied the process of hole transport across pentacene grain boundaries using large-scale quantum mechanics calculations. In this paper, we propose a simplified model for determining the hole transfer rates, which were found to be reduced considerably by hole barriers that were generated near the grain boundaries. By using this model, mesoscale simulations, such as the kinetic Monte Carlo method, can be applied to heterogeneous polycrystalline structures. (C) 2015 The Japan Society of Applied Physics