▎ 摘　　要

Graphene (G)-plasmonic nanoparticles (NPs) systems have found immense nanoscale applications via utilizing the sensitive optical response of graphene to the photo-induced electrons transferred from attached NPs. These electrons are emitted from the plasmonic metal NPs under the influence of a Localized Surface Plasmon Resonance (LSPR). Here, we first present theoretical investigations of the photoemission electrons in the G-plasmonic NPs system influenced by the LSPR of NPs. A rigorous theoretical approach is used to determine the level of photo-exited electrons and the optimal parameters for achieving a highest photoemission yield. The photoemission of electrons is mainly driven by the surface photoelectric effect in which an electron near the particle surface absorbs photon energy and overcomes the potential barrier at the metal-graphene boundary. For a thorough investigation, we study the effects of the material and geometry of NPs and the intensity of the LSPR field on the rate of photoemission. It is shown that silver nanoparticles combined with graphene are more effective in enhancing light-matter interaction in graphene owing to the lower interfacial energy barrier and higher field enhancement. Finally, we verify that the photo-induced electron density predicted by our calculations is matched with that obtained by combining theoretical and Raman-based experimental results.