Prediction of chalcogen-doped VCl${}_3$ monolayers as 2D ferromagnetic semiconductors with enhanced optical absorption

In recent years, 2D ferromagnetic semiconductors have attracted much attention because of its potential application in spintronic devices. Using first-principles calculations, the magnetic and optical properties of intrinsic and chalcogen-doped VCl${}_3$ monolayers are investigated. In contrast to previous work, VCl${}_3$ monolayer is proved to be an antiferromagnetic semiconductor rather than a Dirac half-metal after considering the electronic correlation effect. At a low S concentration x between $\frac{1}{24}$ and $\frac{1}{6}$, S-doped VCl${}_3$ monolayer forms a ferromagnetic semiconductor with a large bandgap and a strong exchange splitting in both valence and conduction bands. As the doping content $x$ increases above $\frac{1}{6}$, S-doped VCl${}_3$ monolayer will change to be an anti-ferromagnetic semiconductor and a non-magnetic metal successively. Moreover, Se- and Te-doped VCl${}_3$ monolayers can also form robust ferromagnetic semiconductors at low doping concentration. In particular, the Curie temperature of Se-doped VCl${}_3$ monolayer can reach 170 K, higher than that of S- and Te-doped VCl${}_3$ monolayers. At last, chalcogen-doped VCl${}_3$ monolayers have enhanced optical absorption in the visible regions compared to intrinsic VCl${}_3$ monolayer. The results show that chalcogen-doped VCl${}_3$ monolayers have promising potential applications in future spintronic and optoelectronic devices. (© 2021 Wiley‐VCH GmbH)