Electronic structure of thin MoS 2 films

The valence electron structure of exfoliated monolayer MoS 2 deposited onto SiO 2 was determined by UV photoelectron spectroscopy through component analysis in combination with Auger electron microscopy. The valence electron cut-off for bulk MoS 2 was found at 0.64 eV binding energy whilst monolayer MoS 2 and few layer MoS 2 have higher binding energies of 0.89 eV and 1.26 eV respectively. SiO 2 is known to interact only weakly with MoS 2 . Thus, the valence electron structure of higher binding energy determined here is thus considered to represent that of a material not affected by strain. The implications of the change in the valence electron cut-off are discussed.