Enhanced Photoluminescence in Transition Metal Dichalcogenides Monolayers by Gold Nanoparticle Supercrystals

Abstract

We developed a nanostructure to enhance the photoluminescence intensity of two-dimensional monolayers of transition metal dichalcogenides based on plasmonic supercrystal arrays. These plasmonic supercrystal arrays are deposited on top the monolayers by means of a template-assisted assembly of gold nanospheres with patterned polydimethylsiloxane molds [1]. These supercrystals arrays consist on square arrays of hexagonally packed gold nanoparticles (50 nm of diameter) which exhibit well-defined surface lattice resonance modes that can be tuned from the visible through the near-infrared by simple variation of the lattice parameter. This tunability can be used to enhance the photoluminescence emission of different transition metal dichalcogenides monolayers. So, as proof of concept, the photoluminescence signal of the monolayer MoS2 and MoSe2 can be significantly enhanced up to 5-6-fold coupling the frequency of the surface lattice resonance of the plasmonic supercrystal to the frequency emission of the transition metal dichalcogenides monolayer. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 840064