First-principles study of the effect of alkaline earth metal doping on the magnetic and photocatalytic properties of monolayer AlN: VN-Hi

Abstract

In the experimental preparation of AlN by chemical vapor deposition, H impurities will inevitably remain, and the intrinsic defect VN will inevitably occur. Incidentally, studies on charged defects are few. In this research, the effect of alkali earth metal doping on the magnetism and photocatalytic properties of single-layer AlN:VN-Hi was studied by first- principles calculations. Al35HiBeN350, Al35HiMgN350, and Al35HiCaN350 have the largest magnetic moments of 1 μB, which are relatively suitable for using as novel two-dimensional spintronic devices. Among all impurity-containing systems, the absorption spectrum of Al35HiCaN350 has the most obvious red shift, with an appropriate band edge position, relatively good carrier activity, difficult recombination of electrons and holes, and the minimum work function. Therefore, single-layer Al35HiCaN350 is the most appropriate photocatalyst for water decomposition given its superior photocatalytic hydrogen evolution. This study is expected to offer theoretical guidance for the development of novel two-dimensional AlN photocatalysts.