In this work, 4x4 organic light emitting diode passive matrices based on new poli(2,7-fluorene phenylidene) (PFP) derivatives have been developed. The fabrication process has involved spin-cast heterostructures that improve charge carrier injection, processing of devices by means of photolithography, together with metallic contact evaporation. Electroluminescent diodes using different polymer derivatives as active layer, and different geometries, have been fabricated and compared. Electrical characterization was carried out in terms of pulsed current-voltage (I-V) measurements. Dependence of the threshold voltage on active material and structural parameters is obtained from the I-V curves, yielding values from 10 V to 25 V. Electroluminescence spectra recorded from the new PFP based devices, as well as commercial polymers, are in good agreement with similar devices found in literature. Finally, experimental data have been fitted using a theoretical model considering several injection and transport mechanisms, including thermionic, reverse, tunnelling, ohmic and space charge limited currents.

Date Published: 7 July 2005
PDF: 9 pages
Proc. SPIE 5840, Photonic Materials, Devices, and Applications, (7 July 2005); doi: 10.1117/12.619152

Published in SPIE Proceedings Vol. 5840:
Photonic Materials, Devices, and Applications
Goncal Badenes; Derek Abbott; Ali Serpenguzel, Editor(s)