Transport energy in organic semiconductors with partially filled localized states

The charge transport in organic semiconductors has been investigated theoretically. An analytical model describing the effect of partially filled localized states on the concept of transport energy is presented, based on variable range hopping theory. The results illustrate that at low enough temperature the partially filled localized states in organic semiconductor systems play an important role on the transport energy. Moreover, the charge concentration will change the transport energy dramatically at higher carrier concentration. The paper also discusses the carrier-concentration-dependent mobility in organic semiconductors. (c) 2008 American Institute of Physics.