Localized-surface-plasmon-enhanced GaN:Eu-based red light-emitting diodes utilizing silver nanoparticles

Abstract

GaN:Eu-based red light-emitting diodes (LEDs), characterized by spectrally stable and narrow-wavelength operation, have recently reached output-powers respectable for commercialization. Further enhancement of Eu3+ luminescence is currently being pursued in order to facilitate their implementation into next-generation applications, such as micro-LED displays. In this letter, we demonstrate localized-surface-plasmon (LSP)-enhanced GaN:Eu-based red LEDs utilizing Ag nanoparticles (NPs) as one of the approaches to enhance the output power. Size-controllable NPs are formed by Ag deposition on the GaN:Eu followed by thermal annealing. The photoluminescence intensity of the GaN:Eu LEDs with the NPs increases by 340% compared to those without the NPs. A shorter emission lifetime of the LEDs with the NPs demonstrates the coupling of Eu3+ ions to the LSPs. Furthermore, the LEDs with the NPs show an enhancement of the output power of 210% under current injection due to LSP coupling.