Journal of Polymer Research

, Volume 13, Issue 1, pp 79–84

Miscibility and Luminescence Properties of MEH-PPV/DPO-PPV Polyblends

Authors

  • Hsuan-Liang Chou
    • Department of Material Science and EngineeringNational Taiwan University
    • Department of Material Science and EngineeringNational Taiwan University
  • Ding-Chang Wang
    • Ritekdisplay Corporation
Article

DOI: 10.1007/s10965-005-9017-7

Cite this article as:
Chou, H., Lin, K. & Wang, D. J Polym Res (2006) 13: 79. doi:10.1007/s10965-005-9017-7

Abstract

Poly(2-methoxy-5-(2′-ethyl-hexyloxy)-p-phenylenevinylene) (MEH-PPV) and poly(2,3-diphenyl-5-octyl-p-phenylenevinylene) (DPO-PPV) are basically immiscible as verified by fluorescence spectroscopy and differential scanning calorimetry. This immiscibility results in insufficient energy transfer from DPO-PPV to MEH-PPV in photoluminescence. A vertically segregated structure with DPO-PPV green domains dispersing on the MEH-PPV-rich matrix was observed in a spin-cast film by two-photon excitation microscopy. The turn-on voltages for electroluminescence (EL) of polyblends were lower than those of their individual pristine polymers, while their EL quantum efficiencies were higher. Because both the highest occupied molecular orbital and the lowest unoccupied molecular orbital levels of MEH-PPV are higher than those of the DPO-PPV, the energy gap of the vertical heterojunction (1.98 eV) in polyblends is lower than that of the pristine MEH-PPV (2.14 eV), which is believed to result in the improved EL properties.

Key words

conjugated polymersluminescencepolymer light-emitting diodepoly(2-methoxy-5-(2′-ethyl-hexyloxy)-p-phenylenevinylene)polyblends

Copyright information

© Springer 2005