Fabrication and Characterization of GaN-Based Resonant-Cavity Light-Emitting Diodes with Dielectric and Metal Mirrors

摘要

We demonstrated GaN-based resonant-cavity light-emitting diodes (RCLEDs) fabricated on a copper substrate by electroplating and laser lift-off techniques. A TiO2/SiO2 dielectric distributed Bragg reflector (DBR) and an aluminum metal reflector were employed as top and bottom mirrors, respectively. As compared to the conventional LED without a top mirror, improved performances were achieved in RCLED devices due to the resonant cavity effect. We also investigated the effects of the top TiO2/SiO2 dielectric DBR on device characteristics. By tuning the reflectivity of the top dielectric DBR, the optimum RCLED device with the top DBR reflectivity of 55% shows a high output power of 62 mW, an external quantum efficiency of 14.8%, a full width at half maximum (FWHM) of 12 nm for emission spectrum, a 50% viewing angle of 122. and a -3 dB modulation bandwidth of 48 MHz. The results show that the RCLED device with the optimum reflectors has considerable potential for future high-performance application. (C) 2018 The Electrochemical Society.