The progress in modeling of charge transport in disordered organic semiconductors on various length scales, from atomistic to macroscopic, is reviewed. This includes evaluation of charge transfer rates from first principles, parametrization of coarse‐grained lattice and off‐lattice models, and solving the master and drift‐diffusion equations. Special attention is paid to linking the length scales and improving the efficiency of the methods. All techniques are illustrated on an amorphous organic semiconductor, DPBIC, a hole conductor and electron blocker used in state of the art organic light emitting diodes (OLEDs). The outlined multiscale scheme can be used to predict OLED properties without fitting parameters, starting from chemical structures of compounds.

We present the results of a modeling study of the three-dimensional current density in single-carrier sandwich-type devices of disordered organic semiconductors. The calculations are based on a master-equation approach, assuming a Gaussian distribution of site energies without spatial correlations. The injection-barrier lowering due to the image potential is taken into account, so that the model provides a comprehensive treatment of the space-charge-limited current as well as the injection-limited current (ILC) regimes. We show that the current distribution can be highly filamentary for voltages, layer thicknesses, and disorder strengths that are realistic for organic light-emitting diodes and, that, as a result, the current density in both regimes can be significantly larger than as obtained from a one-dimensional continuum drift-diffusion device model. For devices with large injection barriers and strong disorder, in the ILC transport regime, good agreement is obtained with the average current density predicted from a model assuming injection and transport via one dimensional filaments [A. L. Burin and M.

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On page 1955 P. Kordt, D. Andrienko, and colleagues illustrate different approaches for modeling the charge transfer of an amorphous phase of DPBIC, a compound used in hole‐conducting and electron‐blocking layers in blue phosphorescent organic light‐emitting diodes. In particular, it is shown how material properties such as density, radial distribution functions, ionization potentials and electron affinities, energetic disorder, charge mobility, and current–voltage characteristics can be extracted from simulations.