Formation of Ge quantum dots on GaN nanowires by molecular beam epitaxy

Germanium nanocrystals were grown on GaN nanowire sidewalls by molecular beam epitaxy. The transmission electron microscopy measurements revealed the formation of 6-10 nm in size Ge quantum dots, which exhibited diamond cubic crystal structure. Raman spectroscopy indicate that uncapped Ge QDs are stress relaxed compared to ones additionally capped with GaN.