In-situ Raman Spectroscopy of the Graphene / Water Interface of a Solution-Gated Field Effect Transistor: Electron-Phonon Coupling and Spectroelectrochemistry

摘要: We present a novel measurement approach which combines the electrical characterization of solution-gated field effect transistors based on epitaxial bilayer graphene 4H-SiC (0001) with simultaneous Raman spectroscopy. By changing gate voltage, we observed signatures related to resonant electron-phonon coupling. An analysis these bands enabled extraction geometrical capacitance system and an accurate calculation Fermi levels for graphene. intentional application higher voltages allowed us trigger electrochemical reactions, followed in-situ by The reactions showed partially reversible character, as indicated emergence / disappearance peaks assigned C-H Si-H vibration modes well increase decrease defect-related D band intensity. Our setup provides highly interesting platform future spectroelectrochemical research electrically induced sorption processes micrometer scale.