• Aucun résultat trouvé

Synthesis and optical propertiesd of graphene quantum dots

N/A
N/A
Protected

Academic year: 2021

Partager "Synthesis and optical propertiesd of graphene quantum dots"

Copied!
2
0
0

Texte intégral

(1)

HAL Id: cea-02341215

https://hal-cea.archives-ouvertes.fr/cea-02341215

Submitted on 31 Oct 2019

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Synthesis and optical propertiesd of graphene quantum

dots

Julien Lavie, Zhao Shen, Lucile Orcin Chaix, A Narita, Jean-Sébastien

Lauret, Stéphane Campidelli

To cite this version:

Julien Lavie, Zhao Shen, Lucile Orcin Chaix, A Narita, Jean-Sébastien Lauret, et al.. Synthesis and optical propertiesd of graphene quantum dots. Chem2DMat, Aug 2017, Strasbourg, France. �cea-02341215�

(2)

SYNTHESIS AND OPTICAL PROPERTIES OF GRAPHENE

QUANTUM DOTS

J. LAVIEa, S. ZHAOb, L. ORCIN-CHAIXb, A. NARITAc, J-S. LAURETb and S. CAMPIDELLIa

a CEA, IRAMIS, NIMBE, Laboratoire d'Innovation en Chimie des Surfaces et Nanosciences, F-91191 Gif sur Yvette, France. Email: stephane.campidelli@cea.fr

b Laboratoire Aimé Cotton, CNRS, ENS Cachan, Université Paris-Saclay, 91405 Orsay Cedex, France c Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany

Abstract: The outstanding electronic, optical and mechanical properties of

graphene strongly inspire the scientific community at both the fundamental and applicative levels. However, one of the main challenges of the field is the control and modification of graphene electronic properties. It is well known that when a material is reduced to nanoscale dimensions, the electronic confinement induces original size-dependent properties. For the last decade, the size reduction of graphene was mostly done through conventional top-down

approaches to fabricate graphene quantum dots (GQDs)1 or graphene nanoribbons (GNRs) 2.

However, top-down approaches do not allow a sufficient control of the morphology and oxidation state of the edges, which drastically impact the properties. In order to truly control, with the required level of precision, the morphology and the composition of the materials and

of its edges, the bottom-up approach is the relevant way to proceed3,4.

With the aim to study and understand the optical properties of GQD materials, we

performed the bottom-up synthesis5 of different families of nanoparticles exhibiting controlled

shapes and edges. Because of their strong aromatic character graphene nanoparticles tend to aggregate in solution; however, for future application it is of high interest to be able to discriminate the intrinsic absorption and emission of the GQDs from those of aggregates. For example, we observed that by STM and polarized microscopy the GQDs bearing alkyl chains are forming columnar structures with liquid crystal properties in solvents. Here, we study the optical properties of graphene quantum dots as a function of their individualization. Using absorption, steady-state and time-resolved photoluminescence and photoluminescence excitation (PLE) spectroscopy, we try to establish the intrinsic optical properties of the GQDs and understand how the structure influences the properties.

Figure : Molecular Structures of GQDs and their absorption and photoluminescence spectra

1M. Bacon, S.J. Bradley, T. Nann Part. Part. Syst. Charact. 2014, 31, 415-428.

2M. Terrones, A.R. Botello-Méndez, J. Campos-Delgado, F. Lopez-Urias, Y.I. Vega-Cantu, F.J. Rodriguez-Marcias, A L. Elias, E. Munoz-Sandoval, A.G. Cano-Marquez, J.C. Charlier, H. Terrones, Nano Today 2010, 5, 351-372.

3A.C. Grimsdale, K. Müllen, Angew. Chem. Int. Ed. 2005, 44, 5592 – 5629.

4 A. Narita, X.Y. Wang, X. Feng, K. Müllen Surname Chem. Soc. Rev. 2015, 44, 6616. 5 Z. Tomović, M.D. Watson, K. Müllen, Angew. Chem. Int. Ed. 2004, 17, 755 –758.

350 400 450 500 550 600 650 700 750 800 850 900 0,0 0,2 0,4 0,6 0,8 1,0 N o rma lize d i n te n si ty Wavelength (nm) PL_exc@400 nm Absorption 350 400 450 500 550 600 650 700 750 800 850 900 0,0 0,2 0,4 0,6 0,8 1,0 PL_exc@400nm Absorption N o rma lize d i n te n si ty Wavelength (nm)

Figure

Figure : Molecular Structures of GQDs and their absorption and photoluminescence spectra

Références

Documents relatifs

The dots can be used to trap Fe(II) and Cu(II) cations and scavenge radicals, like ABTS • + , due to the radical scavenging properties of sp 2 -carbon domains and to the

Specifically, studies of PL lifetimes have revealed the possibility of alternative emission mechanism, based on delayed charge carrier transfer from excited outer CdS layer of

In the case of weak coupling, the excitons of the fluorescent substances and the metal surface plasmons are typically considered unperturbed. In this regime, the

GQDs with a 4.9 nm size have been produced by treating an organosulfate aqueous solution by an atmospheric microplasma jet in ambient air (Yang, Pai & Chiang 2019). DC

Résumé : À partir d’un cadre réflexif basé sur le monde agro-halieutique (pro- duits de la terre et produits de la mer) en Bretagne et Pays de la Loire, notre argu- mentation

A model of glomerular filtration barrier, composed of endothelial cells, collagen IV, a protein of GBM, and podocytes, were used to examine GQDs passage [22].. Moreover,

Bracket (2.1) is obviously linear in the first and third argument and anti-linear in the second one. The map σ is well defined since the center of T is zero. finite-dimensional

The second chapter focuses on the artist-consultant (two cases, Artists Placement Group & Ocean Earth) and unpacks the spatial and embodied nature of the corporate