Charge-Transfer Plasmon Polaritons at Graphene/?-RuCl₃ Interfaces.

ABSTRACT: Nanoscale charge control is a key enabling technology in plasmonics, electronic band structure engineering, and the topology of two-dimensional materials. By exploiting the large electron affinity of ?-RuCl₃, we are able to visualize and quantify massive charge transfer at graphene/?-RuCl₃ interfaces through generation of charge-transfer plasmon polaritons (CPPs). We performed nanoimaging experiments on graphene/?-RuCl₃ at both ambient and cryogenic temperatures and discovered robust plasmonic features in otherwise ungated and undoped structures. The CPP wavelength evaluated through several distinct imaging modalities offers a high-fidelity measure of the Fermi energy of the graphene layer: E_F = 0.6 eV (n = 2.7 × 10¹³ cm^-2). Our first-principles calculations link the plasmonic response to the work function difference between graphene and ?-RuCl₃ giving rise to CPPs. Our results provide a novel general strategy for generating nanometer-scale plasmonic interfaces without resorting to external contacts or chemical doping.

SUBMITTER: Rizzo DJ 

PROVIDER: S-EPMC7729890 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature