Single-crystalline GaN microdisk arrays grown on graphene for flexible micro-LED application.

We report the growth of single-crystalline GaN microdisk arrays on graphene and their application in flexible light-emitting diodes (LEDs). Graphene layers were directly grown on-sapphire substrates using chemical vapor deposition and employed as substrates for GaN growth. Position-controlled GaN microdisks were laterally overgrown on the graphene layers with a micro-patterned SiOmask using metal-organic vapor-phase epitaxy.