Light Emission Enhancement of GaN-Based Photonic Crystal With Ultraviolet AlN/AlGaN Distributed Bragg Reflector

In this study, we demonstrated two-dimensional (2-D) photonic crystal band-edge coupling operation in the ultraviolet wavelength range. The light extraction enhancement was obtained from the photonic crystal structure with an ultraviolet AlN/AlGaN distributed Bragg reflector (UVDBR). The DBR provides a high reflectivity of 85% with 15-nm stopband width. A fivefold enhancement in photoluminescence emission was also achieved compared with the emission from the unpatterned area on the same sample at 374 nm wavelength. We also study the photonic crystal bandedge coupling with finite-difference time-domain and plane-wave expansion methods.