Computational hole mobilities in (pseudo-)amorphous organic semiconductors

Abstract

The development of novel organic semiconductors with enhanced conducting properties is often hindered by the challenge of accurately describing and modeling charge transport within the (pseudo-)amorphous films typically found in optoelectronic devices. In this study, we present a multiscale computational protocol to predict hole mobilities of non-crystalline hole-transporting materials with order-of-magnitude accuracy. Our approach, which integrates density functional theory, molecular dynamics, docking, and kinetic Monte Carlo simulations, reveals the impact of modeling different film morphologies—amorphous and pseudo-amorphous films as well as docking aggregates—on the charge transport properties of these materials. In particular, we demonstrate that experimentally observed mobility trends across a family of ten hole-transporting molecules, including the enhancement associated with increased aromatic core planarity and extended π-conjugation, can only be reproduced when both amorphous disorder and locally ordered molecular aggregates are explicitly considered. This work establishes a robust, morphology-aware framework for the rational, in silico design and optimization of next-generation organic semiconductors.