Theoretical Investigations for the Formation of InN/GaN(0001) Heterostructures

摘要

The formation processes of InN/GaN heterostructures on GaN(0001) substrate are investigated by means of our ab initio-based approach and Monte Carlo (MC) simulations. Our ab initio calculations reveal that even under Ga-rich conditions the pseudo-(1×1) surface consisting of In in the first layer and Ga in the second layer is more stable than that of Ga in the first layer and In in the second layer. Furthermore, the calculated surface phase diagrams demonstrate that the pseudo-(1×1) surface with In-Ga metal layers can incorporate 2.3 monolayers (MLs) of N atoms under growth conditions. The MC simulations using ab initio calculation data imply that both InGaN alloy and InN/GaN heterostructure can be formed depending on the growth conditions, consistent with the experimental results. On the basis of these findings, the stability of these structures is discussed in terms of the strain accumulation in the resultant structures. [DOI: 10.1380/ejssnt.2014.136]