  Bloch-Boltzmann transport theory fails to describe the carrier diffusion in
current crystalline organic semiconductors, where the presence of
large-amplitude thermal molecular motions causes substantial dynamical
disorder. The charge transport mechanism in this original situation is now
understood in terms of a transient localization of the carriers' wavefunctions,
whose applicability is however limited to the strong disorder regime. In order
to deal with the ever-improving performances of new materials, we develop here
a unified theoretical framework that includes transient localization theory as
a limiting case, and smoothly connects with the standard band description when
molecular disorder is weak. The theory, which specifically adresses the
emergence of dynamical localization corrections to semiclassical transport, is
used to determine a "transport phase diagram" of high-mobility organic
semiconductors.
