Blue-light emission from GaN∕Al0.5Ga0.5N quantum dots

Abstract

The growth by molecular beam epitaxy and the optical properties of GaN∕Al0.5Ga0.5N quantum dots on (0001) sapphire substrates are reported. The quantum dots are spontaneously formed via a two dimensional to three dimensional transition upon growth interruption. Photoluminescence over the blue range (435–470nm) is obtained at room temperature by varying the GaN nominal thickness. A weak temperature dependence of the integrated photoluminescence intensity between low temperature and room temperature is observed indicating strong carrier localization in the quantum dots.