Comparative study on the molecular beam epitaxial growth and characterization of AlGaN nanowire structures on AlN buffer layer and on Si

AlGaN in the form of nanowires is an important platform for semiconductor ultraviolet light sources on Si. In the past, significant efforts have been devoted to improving the quality of AlGaN nanowires. In this context, we present a comparative study on the molecular beam epitaxial growth and characterization of AlGaN nanowire structures on the AlN buffer layer on Si and on Si directly. It is found that AlGaN nanowires grown on the AlN buffer layer shows an improved internal quantum efficiency, compared with the nanowires grown on Si directly. This improvement is attributed to the reduced nanowire coalescence due to the improved vertical alignment of the nanowires grown on the AlN buffer layer.