Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Measurement and modeling of carrier transport and exciton formation in blue polymer light emitting diodes

[+] Author Affiliations
R. Coehoorn

Philips Research Labs. (Netherlands) and Eindhoven Univ. of Technology (Netherlands)

S. Vulto, M. Bartyzel

Philips Research Labs. (Netherlands)

S.L.M. van Mensfoort, J. Billen

Eindhoven Univ. of Technology (Netherlands)

H. Greiner, R. Assent

Philips Research Labs. (Germany)

Proc. SPIE 6192, Organic Optoelectronics and Photonics II, 61920O (April 26, 2006); doi:10.1117/12.663096
Text Size: A A A
From Conference Volume 6192

  • Organic Optoelectronics and Photonics II
  • Paul L. Heremans; Michele Muccini; Eric A. Meulenkamp
  • Strasbourg, France | April 03, 2006

abstract

An experimental and modelling study has been carried out of the current-voltage-luminance (J-V-L) characteristics of blue polyfluorene-based organic light emitting devices, with a PEDOT:PSS anode and a Ba/Al cathode. The polymer contains copolymerized hole transporting units that facilitate hole injection. The luminous efficacy for perpendicular emission as a function of the voltage shows a pronounced peak; for an 80 nm thick device, it is equal to 3.3 cd/A at 8 V. At the peak voltage, the external quantum efficiency is 2.2 %. We are working on a comprehensive device model that should provide a framework within which these results can be understood, and present in this paper our intermediate results. Hole and electron transport were studied using devices with a Au and Al cathode and anode, respectively. For hole-only devices a fair description of the temperature and layer thickness dependent J-V curves could be obtained by using a 'conventional' model for the mobility, involving a Poole-Frenkel factor for the field-dependence. For electron-only devices, the analysis is complicated by the presence of an approximately 0.5 eV injection barrier. We have found a parametrization scheme that provides a good description of the experimental J-V curves. A double carrier model that is based on the results of these studies of single-carrier devices provides a good description of the J-V curves of double carrier devices. We have developed a numerical model for the light outcoupling from the optical cavity. For the model parameters assumed, the calculated peak position and shape of the lumunous efficacy as a function of V are in good agreement with the experimental results at room temperature. An analysis is given of the factors that determine the peak height. We argue that a solid physical basis for the model used to describe the electron injection and mobility is still lacking, so that continued electron transport studies will be required.

© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

R. Coehoorn ; S. Vulto ; S.L.M. van Mensfoort ; J. Billen ; M. Bartyzel, et al.
"Measurement and modeling of carrier transport and exciton formation in blue polymer light emitting diodes", Proc. SPIE 6192, Organic Optoelectronics and Photonics II, 61920O (April 26, 2006); doi:10.1117/12.663096; http://dx.doi.org/10.1117/12.663096


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.