Function of quantum-confinement effect in the AlGaNAlNGaN heterostructure with an AlN interfacial layer

This is a theoretical study of the distribution of two-dimensional electron gas (2DEG) in an AlGaNAlNGaN heterostructure. It is shown that the addition of an AlN interfacial layer leads to a slight increase of 2DEG density. The role of quantum-confinement effect in the change of 2DEG distribution with an inserted AlN interfacial layer is revealed by comparing calculated 2DEG distributions in an AlGaN (AlN) GaN heterostructure with and without considering the quantum-confinement effect. In the classic model, insertion of an AlN interfacial layer has a negligible effect on the 2DEG distribution. While taking the quantum effect into account, we can clearly see that incorporation of an AlN interfacial layer results in a substantial influence of 2DEG distribution, with the electron spillover into barrier layer reduced from 1.35× 1012 to 0.23× 1012 cm-2, which are 9.8% and 1.5%, respectively, of the total 2DEG sheet density.