Plasmonic effects of thermally evaporated aluminum nanoparticles on the electroluminescence of organic light-emitting diode subject to exciplex

摘要

We report the investigation of the influence of plasmonic aluminum nanoparticles (Al-NPs), randomly dispersed into the blue organic light-emitting diode (OLED) subject to exciplex emission. The results show that, on the one hand, for the device without Al-NPs, two emission peaks at 437 and 470 nm attributed to excitons of the emitting layer (EML) and exciplexes formed at the hole transport layer/EML interface, respectively. On the other hand, for the device with Al-NPs, the exciplex emission has almost disappeared due to the localized surface plasmonic resonance effect. Moreover, the effective coupling between excitons and localized surface plamson of Al-NPs improved the radiative emission rate of the EML. We observed an enhancement of 50% of the luminous efficiency of the plasmonic-OLED device. In addition to that, the exciton lifetime of the reference sample without metallic nanoparticles is found 1.6 ns, whereas that of the plasmonic sample is prominently decreased to 0.7 ns, emphasizing the plasmonic effect of Al-NPs on the emission of our blue-OLEDs. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)