Chromium is proposed as an ideal metal to form contacts with monolayer MoS2 and WS2

In this paper, fifteen kinds of metal contacts to monolayer MoS2 and WS2 are investigated by first principles calculations. In a variety of metal contacts, the sixth subgroup metals (including Cr, Mo, W) show collective advantages in forming contacts with MoS2 or WS2. They have more favorable interface bonding, higher densities of states at the Fermi level, and lower potential barriers. Molybdenum (Mo) is one of the elements that form molybdenum disulphide (MoS2), and has been proved to form high quality contacts with MoS(2)(.)Z Similarly, tungsten (W) is one of the elements that form tungsten tellurium (WTe2), and is suggested to form favorable contacts with WTe2. The third metal in the sixth subgroup, chromium (Cr), is found here to be a superior metal compared with molybdenum and tungsten to form favorable contacts with molybdenum disulphide and tungsten disulphide. In all sixth subgroup metal contacts, Cr/MoS2 and Cr/WS2 show the best electronic transport properties and chromium has a lower melting point than molybdenum and tungsten, which lead to easier to process devices with transition-metal dichalcogenides.