Successful Fabrication of GaN Epitaxial Layer on Non‐Catalytically‐grown Graphene

Abstract

Sapphire is widely used as a substrate for the growth of GaN epitaxial layer (EPI), but has several drawbacks such as high cost, large lattice mismatch, non‐flexibility, and so on. Here, we first employ graphene directly grown on Si or sapphire substrate as a platform for the growth and lift‐off of GaN‐light‐emitting diode (LED) EPI, useful for not only recycling the substrate but also transferring the GaN‐LED EPI to other flexible substrates. Sequential standard processes of nucleation/recrystallization of GaN seeds and deposition of undoped (u‐) GaN/AlN buffer layer were done on graphene/substrate before the growth of GaN‐LED EPI, accompanied by taping and lift‐off of u‐GaN/AlN or GaN‐LED EPI. This approach can overcome the limitations by the catalytic growth and transfer of graphene, and make the oxygen‐plasma treatment of graphene for the growth of GaN EPI unnecessary.