Metal-Site Dopants in Two-Dimensional Transition Metal Dichalcogenides

Two-dimensional transition metal dichalcogenides (2D TMDs), have received a lot of attention for having notable structural, electrical and optical properties. 2D TMDs can be further tuned through the implementation of substitutional dopants. This work utilizes density functional theory in order to screen the effects of six different transition metal-site dopants (Mo, Ni, Sc, Ti, V, and W) on the structural and electrical properties of 2D MX₂ (M = Mo and W; X = S, Se, and Te). Dopant stability was found to be largely dependent on the atomic radii of the dopant and host metal atoms. Electronic band gap calculations reveal W-doped MoX₂ and Mo-doped WX₂ to be among the only observed semiconductors. The photosensitivity and photoresponsivity are significantly enhanced by doping with Sc or Ni. This work offers an extensive investigation of metal-site dopants and their impact on 2D MX₂ materials.