Fig. 2: Raman and XPS characterizations of MoS₂ growing on NPG.

a Raman spectra of monolayer and multi-layer MoS₂ on NPG. b Mo 3d and c S 2p core-level peaks of MoS₂ grown on NPG and glass. d Au 4 f core-level peaks of original NPG and MoS₂ grown on NPG.