Improved efficiency of green GaN LEDs via exciton–surface plasmon coupling by Au nanoclusters embedded in a micro-hole patterned p-GaN layer

We report green light emitting diodes (LEDs) with Au nanoclusters in a micro-hole patterned p-GaN layer (ANCs-MHPP) to improve the light emission efficiency. Low-temperature photoluminescence (PL) and time-resolved PL showed that green LEDs with ANCs-MHPP demonstrated higher internal quantum efficiencies and faster decay times compared to conventional green LEDs. In addition, the opto-electronic performance of green LEDs with ANCs-MHPP was remarkable. These results can be attributed to the exciton–surface plasmon coupling between excitons in multi-quantum wells and surface plasmons of Au nanoclusters and the surface texturing effect caused by the geometrical shape of the micro-hole patterned p-GaN layer.