Photoluminescence and Surface Potential Characterizations of MoS₂ Monolayers on Periodic Au Nanostructures

MoS₂ monolayers were prepared on hexagonal arrays of Au nanotriangles (NTs) and nanoholes (NHs), fabricated by nanosphere lithography. Photoluminescence (PL) and optical reflectivity spectra of the samples on the Au NT and NH arrays were investigated. The surface plasmon excitation and Wood anomaly affected the reflectivity data, which could be clearly explained by numerical simulations. Also, light-induced surface potential change, determined by spatial distribution of the photo-generated charge carriers, was studied using Kelvin probe force microscopy. The comparison of the two kinds of samples on the NT and NH arrays could show us how the periodic metal nanostructures influenced the physical characteristics of the MoS₂ layers.