Investigation on organic magnetoconductance based on polaron-bipolaron transition

Abstract

We explore the magnetoconductance (MC) effect in an organic semiconductor device based on the magnetic field related bipolaron formation. We present the transition among spin-parallel spin-antiparallel polaron pairs and bipolarons with a group of dynamic equations. The transition rates are adjusted by the external magnetic field as well as the hyperfine interaction. By considering the mobility of polarons different from that of bipolarons, we obtain the MC in an organic semiconductor device. The theoretical calculation is well consistent to the experimental results. It is predicated that a maximum MC appears at a suitable branching ratio of bipolarons. © 2012 American Institute of Physics.