[摘要]:The magnetoelectroluminescence (MEL)of organic light emitting devices with a N,N'-bis(1-naphthyl)- N,N'-diphenyl-1,1'-biphentl-4,4'-diamine:tris-(8-hydroxyquinoline)aluminum (NPB: Alq(3)) mixed emission layer (EML) has been investigated. We find that MEL is maximized when the volume ratio of NPB of the mixed EML reaches 30% and the EML thickness is 40 nm. The features of MEL under various magnetic field strengths are insensitive to the change in EML thickness and mixing ratio. Meanwhile, MEL has a close relationship with the carrier mobility. We have conducted a theoretical study to further verify the relationship. Our experimental and theoretical results confirm that MEL can function as a tool to indicate the mobility. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3505343]