Enhanced optical output and reduction of the quantum-confined Stark effect in surface plasmon-enhanced green light-emitting diodes with gold nanoparticles.

We report the optical properties of localized surface plasmon (LSP)-enhanced green light-emitting diodes (LEDs) containing gold (Au) nanoparticles embedded in a p-GaN layer. The photoluminescence (PL) and electroluminescence (EL) intensities of a green LED with Au nanoparticles were enhanced by the coupling between excitons and LSPs. Excitation power-dependent PL and injection current-dependent EL measurements revealed that the blue-shift of PL and EL peaks with increasing carrier density was smaller for the LSP-enhanced LED compared with that for a conventional LED. The increased optical output power and decrease in blue-shift of the LED with Au nanoparticles were attributed to the increased radiative recombination efficiency of carriers induced by the LSP-coupling process and the compensation of the polarization-induced electric fields with LSP-enhanced local fields, both of which suppressed the quantum-confined Stark effect.