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(295) Production(s) de l'année 2019
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Direct band-gap crossover in epitaxial monolayer boron nitride 
Auteur(s): Elias C., Valvin P., Pelini T., Summerfeld Alex, Mellor Chris, Cheng T.s., Eaves L., Foxon C.t., Beton Peter, Novikov Sergei, Gil B., Cassabois G.
(Article) Publié:
Nature Communications, vol. 1 p.1 (2019)
Texte intégral en Openaccess : 
Ref HAL: hal-02156532_v1
DOI: 10.1038/s41467-019-10610-5
WoS: 000471586700016
Exporter : BibTex | endNote
23 Citations
Résumé: Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unex- plored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the tech- nique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.
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Phase Contrast MRI Suggests an Internal Carotid Vascular Tone Alteration in Migraines
Auteur(s): Deverdun J., Leboucq Nicolas, Pfeuffer Josef, Rivier Francois, Bousquet Elisa, Benali Amel, Le Bars E.
(Article) Publié:
Neuropediatrics, vol. p. (2019)
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Passive and active microrheology of a lyotropic chromonic nematic liquid crystal disodium cromoglycate
Auteur(s): Habibi Ahlem, Blanc C., Mbarek Nadia Ben, Soltani Taoufik
(Article) Publié:
Journal Of Molecular Liquids, vol. 288 p.111027 (2019)
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Peptide-route functionalization of chalcogenide films
Auteur(s): Robert B., Martin Fernandez M., Varga B., Bendoula Ryad, Escalier Raphael, Gergely C., Vigreux Caroline
Ouvrage: (2019)
Ref HAL: hal-02143921_v1
DOI: 10.1109/ICTON.2019.8840343
Exporter : BibTex | endNote
Résumé: Functionalizing the surface of chalcogenide films is of major interest due to the wide use of these materials in infrared integrated optics. A functionalization route via short peptides that has been already used for silicon, ZnSe and other semiconductors is applied to amorphous films of the ternary Ge-Se-Te system. The biotinylated 12-mer peptides LLADTTHHRPWT and SVSVGMKPSPRP were chosen and used to capture streptavidin. High-resolution atomic force microscopy images highlight that the 12-mer peptide LLADTTHHRPWT provides better interface layers for streptavidin molecule detection.
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Fundamental limits for nondestructive measurement of a single spin by Faraday rotation
Auteur(s): Scalbert D.
(Article) Publié:
Physical Review B, vol. 99 p.205305 (2019)
Texte intégral en Openaccess : 
Ref HAL: hal-02142651_v1
DOI: 10.1103/PhysRevB.99.205305
WoS: WOS:000467726600010
Exporter : BibTex | endNote
2 Citations
Résumé: Faraday rotation, being a dispersive effect, is commonly considered as the method of choice for nondestructive detection of spin states. Nevertheless Faraday rotation is inevitably accompanied by spin flips induced by Raman scattering, which compromises nondestructive detection. Here, we derive an explicit general relation relating the Faraday rotation and the spin-flip Raman scattering cross sections, from which precise criteria for nondestructive detection are established. It is shown that, even in ideal conditions, nondestructive measurement of a single spin can be achieved only in anisotropic media. Monolayers of transitions metal dichalcogenides are shown to be promising candidates for this purpose.
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Spontaneous emission of color centers at 4eV in hexagonal boron nitride under hydrostatic pressure
Auteur(s): Koronski Kamil, Kaminska Agata, Zighadlo Nikolai d, Elias C., Cassabois G., Gil B.
(Article) Publié:
Superlattices And Microstructures, vol. 131 p.1 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02141847_v1
DOI: 10.1016/j.spmi.2019.05.018
WoS: 000475999900001
Exporter : BibTex | endNote
3 Citations
Résumé: The light emission properties of color centers emitting in 3.3–4 eV region are investigated for hydrostatic pressures ranging up to 5 GPa at liquid helium temperature. The light emission energy decreases with pressure less sensitively than the bandgap. This behavior at variance from the shift of the bandgap is typical of deep traps. Interestingly, hydrostatic pressure reveals the existence of levels that vary differently under pressure (smaller increase of the emission wavelength compared to the rest of the levels in this energy region or even decrease of it) with pressure. This discovery enriches the physics of the color centers operating in the UV in hBN.
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Surface-Synthesized Graphene Nanoribbons for Room Temperature Switching Devices: Substrate Transfer and ex Situ Characterization
Auteur(s): Borin Barin Gabriela, Fairbrother Andrew, Rotach Lukas, Bayle M., Paillet M., Liang Liangbo, Meunier Vincent, Hauert Roland, Dumslaff Tim, Narita Akimitsu, Müllen Klaus, Sahabudeen Hafeesudeen, Berger Reinhard, Feng Xinliang, Fasel Roman, Ruffieux Pascal
(Article) Publié:
Acs Applied Nano Materials, vol. 2 p.2184-2192 (2019)
Texte intégral en Openaccess :
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