Effects of gold based dimers on structural and electronic properties of MoS₂

Highlights: • Semiconductor MoS₂ shows metallic character by AuPt and AuPd adsorption. • MoS₂ maintains its semiconductor characteristics with a decrease in the band gap values after AuAg, AuCu, and AuAl adsorption. • AuPt adsorbed system is the most stable structure energetically. • AuAl exhibits the weakest adsorption to MoS₂ among the considered dimers. - Abstract: In view of first principles calculations, we investigate the electronic structure redecoration of monolayer MoS₂ upon adsorptions of AuAg, AuPt, AuPd, AuCu, and AuAl bimetallic dimers. Geometrical structure, band structures, electronic density of states, charge density differences of dimer adsorbed MoS₂ systems are presented and discussed. All the systems studied have non-magnetic ground states. Charge transfers occur from dimer to surface except for AuPt adsorption. Our results indicate that the semiconductor MoS₂ maintains its semiconductor character with decreased band gaps upon AuAg, AuCu, and AuAl adsorptions. However, MoS₂ shows metallic behaviour by AuPt and AuPd adsorptions, so Pt-d and Pd-d states cross Fermi level yielding metallic character. AuPt adsorbed system has the highest E_ads value of 3.15 eV indicating the most stable structure energetically among the dimer adsorbed MoS₂ systems considered.