Efficient blue phosphorescent organic light-emitting diodes enabled by Ag-nanoparticles-embedded hole transporting layer

Abstract We reported our effort to develop efficient blue phosphorescent organic light-emitting diodes (PhOLEDs) by embedding an ultrathin layer of Ag nanoparticles (NPs) in the hole transporting layer (HTL). The experimental results support the theoretical simulation in showing that the enhancement in EL performance of the PhOLEDs was attained via the coupling between the excitons and the localized surface plasmons, generated by the embedded Ag NPs in the HTL. Compared to the control device with a conventional organic HTL, the PhOLEDs with an Ag-NPs-embedded HTL have an enhanced luminous efficiency of 31.50 cd/A and a higher power efficiency of 19.08 lm/W, that were 2.5 times higher than the luminous efficiency of a control PhOLED (12.75 cd/A) and 2.4 times higher than the power efficiency of the control device (8.35 lm/W). The use of an Ag-NPs-embedded HTL also is beneficial for reducing the efficiency roll-off in blue PhOLEDs.