Interfacial Defect Engineering on Electronic States of Two-Dimensional AlN/MoS₂ Heterostructure

Abstract

The effects of vacancies and doping defects on the electronic and magnetic states of two–dimensional (2D) AlN/MoS2 heterostructure are investigated by first–principle calculation. Because of charge transfer from the AlN layer to the interstitial region between layers, the energy band structure of the AlN/MoS2 heterostructure is not a simple superposition of those of AlN and MoS2. The energy band alignment can be further tuned by introducing vacancies and doping at the interface. When the AlN layer is decorated by N vacancies or n–type doped, noticeable charge transfer to the conduction band of the MoS2 layer is observed and the band alignment maintains type–I. However, in the case of p–type doping, for instance, C substituting for N (CN) in the AlN sublayer, the band alignment changes to type–II. Moreover, Al vacancies and BeAl/CN doping produce asymmetrical spin–up and spin–down states, which leads to magnetization of the AlN/MoS2 heterostructure. The results demonstrate the significant effects of interfacial defects on the physical properties of 2D heterostructures.