References of "Attaccalite, Claudio"
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See detailDirect and indirect excitons in boron nitride polymorphs: A story of atomic configuration and electronic correlation
Sponza, Lorenzo; Amara, Hakim; Attaccalite, Claudio et al

in Physical Review. B, Condensed Matter (2018), 98(12), 125206

We present a detailed discussion of the electronic band structure and excitonic dispersion of hexagonal boron nitride (hBN) in the single layer configuration and in three bulk polymorphs (usual AA′ ... [more ▼]

We present a detailed discussion of the electronic band structure and excitonic dispersion of hexagonal boron nitride (hBN) in the single layer configuration and in three bulk polymorphs (usual AA′ stacking, Bernal AB, and rhombohedral ABC). We focus on the changes in the electronic band structure and the exciton dispersion induced by the atomic configuration and the electron-hole interaction. Calculations are carried out at the level of ab initio many-body perturbation theory (GW and Bethe Salpeter equation) and of a purposely developed tight-binding model. We confirm the change from direct to indirect electronic gap when going from single layer to bulk systems and we give a detailed account of its origin by comparing the effect of different stacking sequences. We emphasize that the inclusion of the electron-hole interaction is crucial for the correct description of the momentum-dependent dispersion of the excitations. As a result the electron-hole dispersion is flatter than the one obtained from the band structure. In the AB stacking this effect is particularly important as the lowest-lying exciton is predicted to be direct despite the indirect electronic band gap. [less ▲]

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See detailEfficient Gate-tunable light-emitting device made of defective boron nitride nanotubes: from ultraviolet to the visible
Attaccalite, Claudio; Wirtz, Ludger UL; Marini, Andrea et al

in Scientific Reports (2013), 3

Boron nitride is a promising material for nanotechnology applications due to its two-dimensional graphene-like, insulating, and highly-resistant structure. Recently it has received a lot of attention as a ... [more ▼]

Boron nitride is a promising material for nanotechnology applications due to its two-dimensional graphene-like, insulating, and highly-resistant structure. Recently it has received a lot of attention as a substrate to grow and isolate graphene as well as for its intrinsic UV lasing response. Similar to carbon, one-dimensional boron nitride nanotubes (BNNTs) have been theoretically predicted and later synthesised. Here we use first principles simulations to unambiguously demonstrate that i) BN nanotubes inherit the highly efficient UV luminescence of hexagonal BN; ii) the application of an external perpendicular field closes the electronic gap keeping the UV lasing with lower yield; iii) defects in BNNTS are responsible for tunable light emission from the UV to the visible controlled by a transverse electric field (TEF). Our present findings pave the road towards optoelectronic applications of BN-nanotube-based devices that are simple to implement because they do not require any special doping or complex growth. [less ▲]

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See detailDoped Graphene as Tunable Electron-Phonon Coupling Material
Attaccalite, Claudio; Wirtz, Ludger UL; Lazzeri, Michele et al

in Nano Letters (2010), 10(4), 1172-1176

we present a new way to tune the electron phonon coupling (EPC) in graphene by changing the deformation potential with electron/hole doping. We show the EPC for highest optical branch at the high symmetry ... [more ▼]

we present a new way to tune the electron phonon coupling (EPC) in graphene by changing the deformation potential with electron/hole doping. We show the EPC for highest optical branch at the high symmetry point K acquires a strong dependency on the doping level due to electron electron correlation not accounted in mean-field approaches. Such a dependency influences the dispersion (with respect to the laser energy) of the Raman D and 2D lines and the splitting of the 2D peak in multilayer graphene. Finally this doping dependence opens the possibility to construct tunable electronic devices through external control of the EPC. [less ▲]

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See detailImpact of the electron-electron correlation on phonon dispersion: Failure of LDA and GGA DFT functionals in graphene and graphite
Lazzeri, Michele; Attaccalite, Claudio; Wirtz, Ludger UL et al

in Physical Review B (2008), 78(8),

We compute the electron-phonon coupling (EPC) of selected phonon modes in graphene and graphite using various ab initio methods. The inclusion of nonlocal exchange-correlation effects within the GW ... [more ▼]

We compute the electron-phonon coupling (EPC) of selected phonon modes in graphene and graphite using various ab initio methods. The inclusion of nonlocal exchange-correlation effects within the GW approach strongly renormalizes the square EPC of the A(1)' K mode by almost 80% with respect to density-functional theory in the LDA and GGA approximations. Within GW, the phonon slope of the A(1)' K mode is almost two times larger than in GGA and LDA, in agreement with phonon dispersions from inelastic x-ray scattering and Raman spectroscopy. The hybrid B3LYP functional overestimates the EPC at K by about 30%. Within the Hartree-Fock approximation, the graphene structure displays an instability under a distortion following the A(1)' 'phonon at K. [less ▲]

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See detailComment on "Huge Excitonic Effects in Layered Hexagonal Boron Nitride"
Wirtz, Ludger UL; Marini, Andrea; Gruning, Myrta et al

in Physical Review Letters (2008), 100(18),

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See detailAbsorption of BN nanotubes under the influence of a perpendicular electric field
Attaccalite, Claudio; Wirtz, Ludger UL; Marini, Andrea et al

in PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS (2007), 244(11), 4288-4292

We calculate the optical absorption spectra of prototype (6,6) and (9,9) BN nanotubes in the presence of a perpendicular electric field. This model mimics a gated BN nanotube device. Even though the band ... [more ▼]

We calculate the optical absorption spectra of prototype (6,6) and (9,9) BN nanotubes in the presence of a perpendicular electric field. This model mimics a gated BN nanotube device. Even though the band-gap of the tubes decreases strongly as a function of the electric field strength, the absorption spectrum of the pure tubes remains remarkably constant up to high field-strength. We show that, in contrast, the levels which are responsible for defect-mediated photo-luminescence are shifted by the electric field. We address the use of BN nanotubes for optoelectronic applications. 0 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. [less ▲]

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