Metallicity of 2H-MoS₂ induced by Au hybridization

Recent studies have shown that MoS₂ can undergo a structural phase transition from the 2H to 1T′ phase on Au substrates at moderate temperatures. Here, we use ultraviolet and x-ray photoelectron spectroscopy, Raman and photoluminescence spectroscopy, and scanning tunneling microscopy/spectroscopy to probe the impact of annealing exfoliated, monolayer MoS₂ on Au. Our results across multiple length scales indicate that 2H-MoS₂ becomes hybridized with Au upon thermal annealing without inducing the 1T′ structural phase and the bandgap can be modulated to zero width depending on the degree of hybridization. These results can be used to control the resistance of metal-MoS₂ contacts at the atomic scale without introduction of defects or structural phase transitions and are important for devices such as memristors. (paper)