GRACE: GRaphene-Ag nanocrystals as Coupled Electron Systems
Research project selected under the 2011 call for proposals
Principal Investigator :
Jérémie GRISOLIA ()
LPCNO (Equipe Nanotech)
Type of project : Collaborative Project
Partner team(s) :
CEMES (NMAT et GNS)
Date (start/end) : 2012 - 2014
(a) Cross-sectional TEM image showing the opto-electric spacing.
(b) Comparison between the SEM image of a stencil used for fabricating an embedded grating and the corresponding Raman image of AgNPs.
(c) Image of a graphene flake deposited on an implanted SiO2 layer (See (a) for a cross-sectional TEM image); a copper grid (pitch 25µm) was used as stencil mask.
(d) Raman image built with the 2D phonon mode of grapheme
(e) Raman image built with the electron-hole excitations in silver.
Abstract
The award of the 2010 Nobel Prize in physics to A. Geim and K. Novoselov focused on the potential of graphene layers for multiple applications using its wonderful electrical, optical, mechanical and thermal properties. In particular, future electronic devices could be made up of graphene-based field-effect transistors due to the very high mobility of charge carriers. The extraordinary properties of graphene are very sensitive to its structure (flatness, number of layers, edge structures, doping,…) and to its interaction with the supporting substrate or surrounding molecules. For any device application it is necessary to control the density and character of charge carriers while preserving the advantageous electronic structure of the material.
Moreover, nanometer sized metallic particles (MNCs) are at the core of current advancements in nanoscience and nanotechnology, in particular for optical/plasmonic applications ranging from chemical (bio) sensors, surface-enhanced spectroscopy (SES) to miniaturized optical wave guides amplifiers or volatile flash memories. Much effort has been devoted to comprehension of SER (Raman) S mechanisms and to fabrication of SERS-active substrates, leading to thousands of publications and numerous patents since its discovery in 1974. GRACES project concerns the understanding and control of electromagnetic interactions and charge transfer between two ultimate electronic nanosystems by both measurements and modeling: the 2D electron gas of Dirac fermions in graphene and surface plasmons localized on metallic nanocrystals. Three partners of NEXT will combine complementary skills in material science engineering, nanotechnologies, solid state nanophysics, optical spectroscopies, transport measurements and physico-chemistry to design and elaborate specific architectures. They will offer a new approach to modulate and analyze simultaneously electro-optical and transport properties. The most crucial parameter, i.e. the distance between the subsystems, will be finely controlled with nanometer accuracy allowing a progressive tuning from electric field polarization to charge transfer for both transport properties and light scattering enhancement over a large perfectly flat area