Journal of Electronic Materials

, Volume 20, Issue 11, pp 945–948

Improved efficiency in semiconducting polymer light-emitting diodes


  • D. Braun
    • Institute for Polymers and Organic SolidsUniversity of California
  • A. J. Heeger
    • Institute for Polymers and Organic SolidsUniversity of California
  • H. Kroemer
    • Department of Electrical and Computer EngineeringUniversity of California

DOI: 10.1007/BF02816037

Cite this article as:
Braun, D., Heeger, A.J. & Kroemer, H. Journal of Elec Materi (1991) 20: 945. doi:10.1007/BF02816037


We report visible light emission from metal-polymer diodes made from semiconducting polymers, with indium-tin oxide as the “ohmic” contact, and a variety of metals as the barrier metal. Our results, which confirm the discovery by the Cambridge group [Nature347, 539 (1990)], demonstrate that light-emitting diodes can be fabricated by casting the polymer film on indium-tin oxide from solution with no subsequent polymer processing or heat treatment required. Electrical characterization reveals diode behavior with rectification ratios greater than 105 at sufficiently high voltages. Use of an electrode material with low work function leads to more than an order of magnitude improvement in the room-temperature efficiency of the devices. For example, the most efficient devices made with calcium as the rectifying contact display efficiencies of 0.01 photons per electron.

Key words

Bariumcalciumelectroluminescenceindiumlight-emitting diode (LED)magnesiumpoly(2-methoxy,5-(2’-ethyl-hexoxy)-l,4-phenylene-vinylene)semiconducting polymer
Download to read the full article text

Copyright information

© The Minerals, Metals & Materials Society 1991