Abstract
We report on the successful fabrication of InGaN/AlGaN single-quantum-well two-dimensional photonic crystal nanocavities with excellent structural properties by means of a novel method. GaN can be selectively decomposed at around 1000 °C under NH3/H2 ambient conditions, leaving air-bridge AlGaN membranes. The proposed method is remarkably simple and offers various advantages such as good crystalline quality and smooth surfaces over those previously reported. The high quality of the nanocavities has been proven by microscopic photoluminescence: quality factors as high as 5100 have been achieved with a 180-nm-period L7 nanocavity at room temperature.