Atomic-layer epitaxy of GaN quantum wells and quantum dots on (0001) AlN

摘要

We show that a dynamically stable Ga film is formed on (0001) AlN in a large range of Ga fluxes at a substrate temperature of 740℃. This feature allows for atomic layer epitaxy (ALE) of GaN on AlN by alternate exposure to Ga and N flux. We show that, at a growth temperature of 740℃, one ALE cycle leads to the formation of a two-dimensional GaN layer, whereas further cycles lead to the formation of GaN quantum dots following a Stranski-Krastanov growth mode. This behavior is confirmed by atomic force microscopy, transmission electron microscopy, and cathodoluminescence.