  We present a simple model of the local order in amorphous organic
semiconductors which naturally produces a spatially correlated exponential
density of states (DOS). The dominant contribution to the random energy
landscape is provided by electrostatic contributions from dipoles or
quadrupoles. An assumption of the preferable parallel orientation of neighbor
quadrupoles or antiparallel orientation of dipoles directly leads to the
formation of the exponential tails of the DOS even for a moderate size of the
ordered domains. The insensitivity of the exponential tail formation to the
details of the microstructure of the material suggests that this mechanism is
rather common in amorphous organic semiconductors.
