Efficiency enhancement of organic light emitting diode via surface energy transfer between exciton and surface plasmon

Abstract

Organic light emitting diodes (OLEDs) with surface plasmon (SP) enhanced emission have been fabricated. Gold nanoclusters (GNCs) deposited using thermal evaporation technique has been used for localization of surface plasmons. Size of GNCs and distance of GNCs from the emissive layer have been optimized using steady state and time resolved photoluminescence (PL) results. 3.2 Times enhancement in PL intensity and 2.8 times enhancement in electroluminescence intensity of OLED have been obtained when GNCs of size 9.3 nm has been introduced at a distance of 5 nm from emissive layer. Distance dependence of energy transfer efficiency between exciton and SPs was found to be of 1/ R 4 type, which is typically the dependence for dipole-surface energy transfer.