2HTMDs
2H-transition metal dichalcogenides (2H-TMDs) are a class of layered crystalline materials with the formula MX2, where M is a transition metal such as molybdenum (Mo) or tungsten (W), and X is a chalcogen such as sulfur (S) or selenium (Se). They crystallize predominantly in the 2H polytype, a hexagonal structure characterized by layers where a metal atom is sandwiched between two chalcogen atoms. Each layer features trigonal prismatic coordination of the metal, and the unit cell contains two MX2 layers with a specific AB stacking pattern.
In the 2H polytype, neighboring layers align in a way that preserves hexagonal symmetry and yields semiconducting
Common examples of 2H-TMDs include MoS2, MoSe2, WS2, and WSe2. These materials are typically prepared by exfoliation
See also: transition metal dichalcogenides; 2H polytype; MoS2.