Interface instabilities in polymer light emitting diodes due to annealing

Autor: L.J. van IJzendoorn, M.J.A. de Voigt, Martijn Kemerink, F.J.J. Janssen, H.F.M. Schoo, A. W. Denier van der Gon, HH Hidde Brongersma, Jacobus Marinus Sturm
Přispěvatelé: Molecular Materials and Nanosystems
Jazyk: angličtina
Rok vydání: 2003
Předmět:
Zdroj: Organic Electronics, 4(4), 209-218. Elsevier
ISSN: 1566-1199
DOI: 10.1016/S1566-1199(03)00017-X
Popis: In polymer light emitting diodes (PLEDS) with an (ITO/PPV/Ca) structure we obsd. a significant redn. of both the current and the light output at const. voltage after heat treatment for only 30 min at 65 DegC. Electroluminescence spectroscopy expts. showed that the shape as well as the amplitude of the spectra were changed.The redn. of current and light output was investigated by measuring I-V and E-V (current-voltage and brightness-voltage) characteristics of PLEDs, I-V characteristics of single carrier devices, and by performing low energy ion scattering and XPS expts. on the Ca/PPV interface.It was concluded that the current and light output redn. could be ascribed to the degrdn. of the Ca/PPV and the ITO/PPV interfaces. The degrdn. of the ITO/PPV interface resulted in a redn. of the zero field hole mobility and a small increase of the field dependence of the mobility. The degrdn. of the Ca/PPV interface, probably by diffusion of calcium into the PPV, resulted in carrier traps and quenching sites, which influenced the field dependent electron mobility
Databáze: OpenAIRE