Translator Disclaimer
1 December 1997 Light-emitting diodes with naphtalimide side-chain polymers: basic properties and role of polymer thickness in two-layer devices
Author Affiliations +
Abstract
We report the fabrication of efficient green light-emitting diodes using a side-chain polymer based on a high-electron affinity (EA) naphtalimide moiety (PNI). The chromophore is attached to a polymethacrylate backbone through a spacer, and emits in the green with high efficiency. In single-layer light-emitting diodes (LEDs), we find that the electroluminescence (EL) efficiency is not limited by Al cathodes as for poly(p-phenylene-vinylene), PPV, and we attribute this to the increased EA. We report maximum internal efficiencies of about 1.7 percent for Ca and 0.9 percent for Al in double-layer devices where PPV serves as both Hole-injector and emitter. Compared to some oxadiazole based electron injection/transport layer, PNI gives higher efficiencies at high currents, and longer lifetimes. Tuning of emission in the red is possible by dye-doping the PNI and causing the emission to happen in this layer. We discuss the properties of the different device configurations with a view to the electronic structure of the materials and in particular to the influence of the thickness of the individual layers on efficiency and driving conditions.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Franco Cacialli, Cecile-Maria Bouche, Pierre L. Le Barny, Hugues Facoetti, Francoise Soyer, Philippe Robin, and Richard H. Friend "Light-emitting diodes with naphtalimide side-chain polymers: basic properties and role of polymer thickness in two-layer devices", Proc. SPIE 3148, Organic Light-Emitting Materials and Devices, (1 December 1997); https://doi.org/10.1117/12.284173
PROCEEDINGS
8 PAGES


SHARE
Advertisement
Advertisement
Back to Top