Tunable Light Emission from GaN-Based Photonic Crystal with Ultraviolet AlN/AlGaN Distributed Bragg Reflector

Abstract

In this paper, the characteristics of GaN-based two-dimensional (2D) photonic crystal bandedge coupling operation with an ultraviolet AlN/AlGaN distributed Bragg reflector (DBR) have been investigated and analyzed. The 25-pair AlN/Al(0.2)GaN(0.8) DBR shows a high reflectivity of 85% at 375nm with the stop-band width of 15nm. A strong light emission was observed from GaN photonic crystals within high reflectivity region of DBR. The emission wavelength can be also manipulated by varying the radius to lattice constant ratio. The photonic crystal bandedge mode was also characterized with three-dimensional plane-wave expansion (PWE) and finite-difference time-domain (FDTD) simulation. (C) 2011 The Japan Society of Applied Physics