Effect of gold nanorods and nanocubes on electroluminescent performances in organic light-emitting diodes and its working mechanism

In this manuscript we investigated the influence of Au nanoparticles on electrical and electroluminescent (EL) performances in organic light-emitting diodes (OLEDs) via doping as-synthesized Au nanorods (NRs) or nanocubes (NCs) into hole transport layer (HTL). Through accurately controlling the distance between the Au NRs and the emitting layer, altering the guest emitter’s lifetime, and replacing Au NRs with Au NCs to satisfy a better spectrum overlap with the emission guest, we got a conclusion that doping Au NRs or NCs into HTL has no significant influence on the device’s electrical and EL performances, although we observed an increase in the spontaneous emission rate in a fluorescent material by the exciton-surface plasmon-coupling. Our results suggest that a further research on emission mechanism in surface plasmon-enhanced OLEDs is still in process.