Non-conventional charge transport in organic semiconductors: magnetoresistance and thermoelectricity
High mobility charge transport in various organic semiconductors is now well documented and well understood. As a result, research is now focussing on more exotic transport properties driving a new generation of organic electronic devices. This mini-review will focus on the two most prominent of these, magnetoresistance and thermoelectricity. Each requires additional properties of materials beyond their ability to transport charge, namely a large resistive response to a magnetic field, or in the case of thermoelectrics a large Seebeck coefficient combined with low thermal conductivity. This mini-review will explore the current state of the art in organic materials for these applications and will discuss current ideas on the molecular and structural origins of their properties with an outlook on future directions for molecular design.