AlGaN/GaN/AlGaN double-heterojunction blue LEDs on 6H-SiC substrates

Blue LEDs with double-heterojunction (DH) have been produced in AIN-GaN system grown on n-type 6H-SiC substrates via metalorganic chemical vapor deposition (MOCVD). These devices employ a GaN active layer bordered by Mg doped p-type Al0.1Ga0.9N and Si doped n-type Al0.1Ga0.9N. A vertical device design was utilized with a p-type Au contact centered on the chip top side for wire bonding. The backside contact to the SiC is Ni. The peak emission from these devices is 430 nm with a FWHM of 65 nm, producing a deep blue color. The output power is 1.7 mW at 20 mA which corresponds to an external quantum efficiency of 3%.