Computational study on the effects of vacancy in wurtzite AlN (0001) and (000[formula omitted]) surfaces

Abstract

In this study, the effects of vacancies in wurtzite AlN (0001) and (0001(—)) surfaces were investigated by performing CASTEP calculations in Materials Studio software. In particular, we comparatively analyzed the electronic structure, magnetism, and partial optical properties of AlN with surface vacancies. The results show that after introducing a vacancy, the band gap of the systems became zero, which represented a metallic characteristic. In addition, both the vacant (0001) and (0001(—)) surfaces as well as their corresponding systems exhibited non-magnetic. Contrastingly, the original systems with an intact (0001) or (0001(—)) surface were ferrimagnetic. Finally, it was found that the presence of the vacancy did not have any evident impact on the absorption and reflection of the AlN systems. Compared with the (0001) system, the (0001(—)) one had greater maximum absorption coefficient and maximum reflectivity.