The charge carrier dynamics in organic semiconductors has been traditionally discussed with the models used in inorganic crystalline and amorphous solids but this analogy has severe limitations because of the more complicated role of nuclear motions in organic materials. In this perspective, we discuss how a new approach to the modelling of charge transport is emerging from the alliance between the conventional quantum chemical methods and the methods more traditionally used in soft-matter modelling. After describing the conventional limit cases of charge transport we discuss the problems arising from the comparison of the theory with the experimental and computational results. Several recent applications of numerical methods based on the propagation of the wavefunction or kinetic Monte Carlo methods on soft semiconducting materials are reviewed.

In partially ordered organic semiconductors, the characteristic times of nuclear motion are comparable to those of charge carrier dynamics. It is impossible to describe charge transport using either static disorder models or temperature averaged electronic Hamiltonians. We build a model Hamiltonian which allows the study of charge transport whenever carrier and nuclear dynamics are not easily separable. Performing nanoseconds long molecular dynamics of a columnar mesophase of a discotic liquid crystal and evaluating electronic couplings, we identify realistic parameters of the Hamiltonian. All modes which are coupled to the electron dynamics can be described in the model Hamiltonian by a limited number of Langevin oscillators. This method can be applied to systems with both slow (nanoseconds) and fast (hundreds of femtoseconds) nuclear motions, i.e., with both dynamic and static disorder.