High-Performance GaN-Based Vertical-Injection Light-Emitting Diodes With TiO$_{2}$–SiO $_{2}$ Omnidirectional Reflector and n-GaN Roughness

We have designed and fabricated a new type of GaN-based thin-film vertical-injection light-emitting diode (LED) with TiO
₂
-SiO
₂
omnidirectional reflector (ODR) and n-GaN roughness. The associated ODR designed for LED operation wavelength at 455 nm was integrated with patterned conducting channels for the purpose of vertical current spreading. With the help of laser lift-off and photo-electrochemical etching technologies, at a driving current of 350 mA and with chip size of 1 mm times 1 mm, the light-output power and the external quantum efficiency of our thin-film LED with TiO
₂
-SiO
₂
ODR reached 330 mW and 26.7%. The result demonstrated 18% power enhancement when compared with the results from the thin-film LED with Al reflector replace