First-principles study for self-limiting growth of GaN layers on AlN(0001) surface


 The GaN thickness dependence of surface structural stability and adsorption behavior of Ga adatom in GaN layers on AlN(0001) surface are investigated on the basis of first-principles calculations to clarify the self-limiting growth on AlN(0001) surface during metal organic vapor phase epitaxy. The calculations demonstrate that the stability of reconstructed GaN layers on AlN(0001) surface is similar to that of GaN(0001) surface irrespective of the GaN film thickness. Furthermore, we find that the adsorption of Ga adatom on AlN(0001) surface easily occurs compared with that of on GaN layers on AlN(0001) surfaces. The difference in the adsorption behavior implies that the growth of GaN layers on AlN(0001) surface is suppressed. The calculated results provide a theoretical guidance for understanding the self-limiting growth of GaN layers, resulting in to the formation mechanism of GaN quantum wells.