Publications

2011

• Synthesis of few-layered graphene by ion implantation of carbon in nickel thin films
  
  • Baraton Laurent
  • He Zhanbing
  • Lee Chang Seok
  • Maurice Jean-Luc
  • Cojocaru Costel Sorin
  • Gourgues-Lorenzon Anne-Françoise
  • Lee Young Hee
  • Pribat Didier
  Nanotechnology, Institute of Physics, 2011, 22, pp.085601, 5 p.. The synthesis of few-layered graphene is performed by ion implantation of carbon species in thin nickel films, followed by high temperature annealing and quenching. Although ion implantation enables a precise control of the carbon content and of the uniformity of the in-plane carbon concentration in the Ni films before annealing, we observe thickness non-uniformities in the synthesized graphene layers after high temperature annealing. These non-uniformities are probably induced by the heterogeneous distribution/topography of the graphene nucleation sites on the Ni surface. Taken altogether, our results indicate that the number of graphene layers on top of Ni films is controlled by the nucleation process on the Ni surface rather than by the carbon content in the Ni film. (10.1088/0957-4484/22/8/085601)
  DOI : 10.1088/0957-4484/22/8/085601
• Méthode de détection d'analytes utilisant des réseaux de transistors à effet de champ à base de nanotubes/nanofils et dispositif électronique associé
  
  • Cojocaru Costel-Sorin
  • Lebental Bérengère
  • Bouanis Fatima
  • Norman Evgeny
  , 2011, pp.16 p. Méthode de détection d'analytes utilisant des réseaux de transistors à effet de champ à base de nanotubes et dispositif électronique associé.
• High-quality Single-walled carbon nanotubes synthesis by hot filament CVD on Ru nanoparticule catalyst
  
  • Bouanis Fatima Zara
  • Baraton Laurent
  • Huc Vincent
  • Pribat Didier
  • Cojocaru Costel Sorin
  Thin Solid Films, Elsevier, 2011, 519 (14), pp.4594-4597. We investigated the single-walled carbon nanotubes (SWCNTs) growth on Ru nanoparticle catalyst via hot filament assisted chemical vapor deposition (HFCVD) with two independent W filaments for the carbon precursor (methane) and the hydrogen dissociation respectively. The Ru nanoparticles were obtained following a two-step strategy. At first the growth substrate is functionalized by silanisation, then a self assembly of a ruthenium porphyrin complex monolayer on pyridine-functionalized metal oxide substrates. We have studied the impact of the filaments power and we optimized the SWCNTs growth temperature. The as grown SWCNTs were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy. It was found that the quality, density and the diameter of SWCNTs depends on the filament and growth temperature. Results of this study can be used to improve the understanding of the growth of SWCNTs by HFCVD. (10.1016/j.tsf.2011.01.326)
  DOI : 10.1016/j.tsf.2011.01.326
• Radiation damage induced at the surface of titanium by argon ions of a few MeV
  
  • Do N.-L.
  • Bérerd N.
  • Moncoffre N.
  • Yang F.
  • Trocellier P.
  • Serruys Y.
  • Gorse-Pomonti D.
  Journal of Nuclear Materials, Elsevier, 2011, 419, pp.168-176. Oxide films thermally grown on titanium in a weakly oxidizing environment (5 × 10−3 Pa of dry air) under irradiation with 2, 4 and 9 MeV argon have been studied. The AFM study reveals a cratering effect of 2, 4 and 9 MeV argon and a significant surface roughening effect of 2 MeV argon, both effects being largely unexpected in this energy range. The XPS analysis shows that the TiO2 stoichiometry of the superficial oxide film is fairly well maintained under argon irradiation. The Spectroscopic Ellipsometry analysis reveals an oxide film thickness multiplied by a factor of three under irradiation with 2 MeV argon by comparison with 9 MeV argon, the irradiation effect on oxide growth remaining very limited for 4 or 9 MeV argon. The possible role of the electronic but most certainly of the nuclear energy losses on the surface damage mechanism are discussed. It is suggested that the oxidizing environment is necessary to freeze the instantaneous surface damage and permits the post-mortem observation. (10.1016/j.jnucmat.2011.07.012)
  DOI : 10.1016/j.jnucmat.2011.07.012
• Surface chemical modifications and surface reactivity of nanodiamonds hydrogenated by CVD plasma
  
  • Arnault Jean-Charles
  • Petit Tristan
  • Girard Hugues
  • Chavanne Anthony
  • Gesset Céline
  • Sennour Mohamed
  • Chaigneau Marc
  Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2011, 13, pp.11481-11487. The present study focuses on the interaction of hydrogen microwave CVD plasma with nanodiamonds (NDs). Hydrogen treated NDs (H-NDs) were characterized using electron spectroscopies (XPS, AES) without air exposure. A surface temperature higher than 700 °C is needed to remove the oxygen present on raw NDs. The kinetics of oxygen removal were investigated. Moreover, UHV annealings of H-NDs after ageing in ambient air clearly underline that 75% of the oxygen is related to physisorbed species. Finally, H-NDs were efficiently grafted using photochemical reaction with alkenes and a spontaneous coupling of aryldiazonium salts. These results confirm similar electronic surface properties between bulk and nano diamond materials. (10.1039/C1CP20109C)
  DOI : 10.1039/C1CP20109C
• Field emission measure of the time response of individual semiconducting nanowires to laser excitation
  
  • Choueib May
  • Ayari Anthony
  • Poncharal Philippe
  • Journet Catherine
  • Cojocaru Costel Sorin
  • Martel Richard
  • Purcell Steven T
  Applied Physics Letters, American Institute of Physics, 2011, 99, pp.072115. A simple technique is explored to determine the temporal photo-response, s, of individual semiconducting SiC and Si nanowires (NWs), with a high time resolution. Laser-assisted field emission (LAFE) from the NWs is first shown to be highly sensitive to continuous laser illumination. Pulsed illumination is then combined with measurements of the total energy distributions to determine s which were rather large, 4-200 ls. The time response scaled roughly with the square of the NWs length and could be attributed to laser-induced heating. LAFE is thus a new tool for quantifying rapid thermo-optical effects in such nano-objects. (10.1063/1.3627168)
  DOI : 10.1063/1.3627168
• Mueller polarimetry as a tool for evaluation of diffraction grating profile asymmetry
  
  • Novikova Tatiana
  • Bulkin Pavel
  • Popov V.
  • Haj Ibrahim Bicher
  • de Martino Antonello
  Journal of Vacuum Science and Technology, American Vacuum Society (AVS), 2011, 29 (5), pp.051804.
• Analysis of textured films and periodic Grating Structures with Mueller Matrices: A new Challenge in Instrumentation with the generation of angle-resolved SE polarimeters
  
  • Ferrieu F.
  • Novikova Tatiana
  • Fallet Clément
  • Ben Hatit Sami
  • Vannuffel Cyril
  • de Martino Antonello
  Thin Solid Films, Elsevier, 2011, 519, pp.2608.
• Conductive-probe atomic force microscopy characterization of silicon nanowires
  
  • Alvarez José
  • Ngo Irène
  • Gueunier-Farret Marie-Estelle
  • Kleider Jean-Paul
  • Yu Linwei
  • Roca I Cabarrocas Pere
  • Rouvière Emmanuelle
  • Celle Caroline
  • Mouchet Céline
  • Simonato Jean-Pierre
  Nanoscale Research Letters, SpringerOpen, 2011, 6, pp.110. The electrical conduction properties of lateral and vertical silicon nanowires (SiNWs) were investigated using a conductive-probe atomic force microscopy (AFM). Horizontal SiNWs, which were synthesized by the in-plane solid-liquid-solid technique, are randomly deployed into an undoped hydrogenated amorphous silicon layer. Local current mapping shows that the wires have internal microstructures. The local current-voltage measurements on these horizontal wires reveal a power law behavior indicating several transport regimes based on space-charge limited conduction which can be assisted by traps in the high-bias regime (> 1 V). Vertical phosphorus-doped SiNWs were grown by chemical vapor deposition using a gold catalyst-driving vapor-liquid-solid process on higly n-type silicon substrates. The effect of phosphorus doping on the local contact resistance between the AFM tip and the SiNW was put in evidence, and the SiNWs resistivity was estimated. (10.1186/1556-276X-6-110)
  DOI : 10.1186/1556-276X-6-110
• Optimized network of multi-walled carbon nanotubes for chemical sensing
  
  • Gohier A.
  • Chancolon Jérôme
  • Chenevier P.
  • Porterat D.
  • Mayne-L'Hermite M.
  • Reynaud C.
  Nanotechnology, Institute of Physics, 2011, 22 (10), pp.105501. This work reports the design of a resistive gas sensor based on 2D mats of multi-walled carbon nanotubes (MWCNTs) grown by aerosol-assisted chemical vapour deposition. The sensor sensitivity was optimized using chlorine as analyte by tuning both CNT network morphology and CNT electronic properties. Optimized devices, operating at room temperature, have been calibrated over a large range of concentration and are shown to be sensitive down to 27 ppb of chlorine. The as-grown MWCNT response is compared with responses of 2000 degrees C annealed CNTs, as well as of nitrogen-doped CNTs and CNTs functionalized with polyethyleneimine (PEI). Under chlorine exposure, the resistance decrease of as-grown and annealed CNTs is attributed to charge transfer from chlorine to CNTs and demonstrates their p-type semiconductor behaviour. XPS analysis of CNTs exposed to chlorine shows the presence of chloride species that confirms electron charge transfer from chlorine to CNTs. By contrast, the resistance of nitrogen-doped and PEI functionalized CNTs exposed to chlorine increases, in agreement with their n-type semiconductor nature. The best response is obtained using annealed CNTs and is attributed to their higher degree of crystallinity. (10.1088/0957-4484/22/10/105501)
  DOI : 10.1088/0957-4484/22/10/105501