Searching for two-dimensional (2D) materials with multifunctionality is one of the main goals of current research in 2D materials. Magnetism and semiconducting are certainly two desirable functional properties for a single 2D material. In line with this goal, here we report a density functional theory (DFT) study of bulk and single-layer magnetic semiconductor ${\mathrm{CrPS}}_4$. We find that the ground-state magnetic structure of bulk ${\mathrm{CrPS}}_4$ exhibits the A-type antiferromagnetic ordering, which transforms to ferromagnetic (FM) ordering in single-layer ${\mathrm{CrPS}}_4$. The calculated formation energy and phonon spectrum confirm the stability of single-layer ${\mathrm{CrPS}}_4$. The band gaps of FM single-layer ${\mathrm{CrPS}}_4$ calculated with a hybrid density functional are within the visible-light range. We also study the effects of FM ordering on the optical absorption spectra and band alignments for water splitting, indicating that single-layer ${\mathrm{CrPS}}_4$ could be a potential photocatalyst. Our work opens up ample opportunities of energy-related applications of single-layer ${\mathrm{CrPS}}_4$.

• Received 9 September 2016

DOI:https://doi.org/10.1103/PhysRevB.94.195307