Naphthalimide side-chain polymers for organic light-emitting diodes: band-offset engineering and role of polymer thickness

Experiment was conducted to examine the fabrication of efficient green light-emitting diodes using a side-chain random polymer based on a high electron affinity (EA) naphthalimide moiety (PNI). Results suggest that the electroluminescence quantum efficiency is not limited by Al cathodes as for poly(p-phenylene vinylene) which is attributed to the increased EA. Findings also indicate that PNI generates higher efficiencies at high currents and longer lifetimes.