Surface plasmon enhanced graphene/p-GaN heterostructure light-emitting-diode by Ag nano-particles

Putting a piece of graphene over p-GaN can form shallow P-N junction near the surface, which can act as light emitting diodes (LEDs) and promise many kinds of light manipulation methods. Herein, we introduce high performance surface plasmon enhanced graphene/p-GaN LEDs by inserting Ag nano-particles (Ag NPs) into the graphene/p-GaN interface. Bidirectional LEDs have been realized with a broad band emission from 550 nm to 650 nm at a forward bias of graphene side and a sharp emission of ~400 nm at a reversed bias of graphene. The emission intensity of graphene/Ag NPs/p-GaN is largely enhanced in both forward and reverse bias situation when compared with the bare graphene/p-GaN heterostructure, which is attributed to the surface plasmon resonance of Ag NPs. These results indicate that graphene/Ag NPs/p-GaN heterojunction is a promising candidate for high brightness LEDs.