Flexible organic light emitting diodes (OLEDs) based on a blue emitting polyfluorene

Vasilopoulou, M., Palilis, L. C., Botsialas, A., Georgiadou, D. G., Bayiati, P., Vourdas, N., Petrou, P. S., Pistolis, G., Stathopoulos, N. A. and Argitis, P. (2008) Flexible organic light emitting diodes (OLEDs) based on a blue emitting polyfluorene. Physica Status Solidi (C) Current Topics in Solid State Physics, 5 (12), 3658-3662. (doi:10.1002/pssc.200780214).

Abstract

Flexible OLEDs were demonstrated using a highly efficient blue electroluminescent polyfluorene derivative. The flexible devices were fabricated on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates with a sheet resistance of 35 Ω per sq. The emitting layer was poly[9,9-di-(2′-ethylhexyl)fluorenyl-2,7-diyl] (PF). A significant improvement of the luminance and device efficiency was achieved by confining the exciton formation zone within PF by two wide band-gap materials, namely PVK as a hole transport layer (HTL) and an inorganic oxide layer (IOL) as an electron transport and hole blocking layer. In order to achieve full-color LEDs based on a common host material, we probed the use of suitable dye emitters dispersed in PF at appropriate concentrations. The selection of the emitters is based on their capability to be effective energy transfer acceptors from the blue emitting PF. In particular, energy transfer was demonstrated from blue to green for PF-doped with the green dye emitter 1-[4-(dimethylamino)phenyl]-6- phenylhexa-1,3,5,-triene (DMA-DPH), and from blue to red for PF-doped with the red dye emitter (4-dimethylamino-4′-nitrostilbene) (DANS). This demonstration paves the way for developing highly efficient blue, green and red flexible OLEDs based on a common blue emitting PF host.

This record has no associated files available for download.

Contributors

Author: D. G. Georgiadou

Download statistics