Space-charge-limited conduction in ethyl–hexyl substituted polyfluorene

  • S. GuhaEmail author
  • M. Arif
  • S. Gangopadhyay
  • U. Scherf


Ethyl–hexyl substituted polyfluorene (PF2/6) is a model blue-emitting polymeric system where the space-charge-limited conduction model within discrete single-level shallow traps can be applied to describe charge transport. Thermal cycling the PF2/6 film to a crystalline phase prevents creation of additional trap states, which is seen in the as-is polymer at higher voltages. These results shed new light on the mechanism of charge transport in polymers. Although PF2/6 has a high degree of interchain disorder, the as-is polymer shows regions of ordering that impacts charge transport through the polymer. Current–voltage characteristics as a function of the polymer thickness reveal the origin of the trap states.


Charge Transport Trap State Polymer Thickness Bulk Trap High Luminescence Efficiency 
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We gratefully acknowledge the support of this work through the National Science Foundation under Grant No. ECCS-0523656. We thank Prof. Kartik Ghosh of Missouri State University for providing us with the ITO substrates.


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© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Department of Physics and AstronomyUniversity of Missouri-ColumbiaColumbiaUSA
  2. 2.Department of Electrical and Computer EngineeringUniversity of Missouri-ColumbiaColumbiaUSA
  3. 3.Makromolekulare ChemieBergische Universität WuppertalWuppertalGermany

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