Adsorption of Cs and O2 on MoS2

Adsorption of Cs on basal planes of MoS₂ has been studied with LEED, Auger and work function measurements. LEED observations show that in the 200–300 K range Cs is adsorbed as amorphous layers on MoS₂. Correlation of Auger and work function measurements indicates that the work function, sticking coefficient and the maximum density of Cs that can be deposited on the MoS₂ surface depend strongly on substrate temperature. Cesium is deposited on MoS₂ in two adsorption states. Although MoS₂ is extremely inert to O₂ adsorption, the presence of Cs causes a drastic increase in the adsorption of oxygen which in turn increases the amount of Cs that can be deposited on the surface. Lastly, it has been found that part of the Cs adatoms are diffused into the bulk of MoS₂.