GaN-Based LEDs With Air Voids Prepared by One-Step MOCVD Growth

The authors report the formation of air voids at GaN/cone-shaped pattern sapphire substrate interface by laser scribing and lateral etching with one-step growth. With 5 and 20 min lateral etching, it was found that pyramid-like air voids were formed with an average height of 0.98 and 1.9 μm, respectively, on top of each cone of the substrate. It was also found that we can enhance LED output power by 11.5% by etching the wafers for 20 min. It was also found that the simulated results agree well with the experimentally observed data.