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In this work, we have investigated the effects of in-plane mechanical strains on the electronic properties of single-layer α-In2Se3 by means of density functional theory (DFT) calculations. Our findings reveal that this system exhibits a semiconductor character with an indirect band gap in the ground state, with a compressive biaxial strain leading to an indirect to direct band gap transition. Remarkably, along with the band gap transition, the system displays promising capability to produce hydrogen gas from a visible light photocatalytic water splitting process.

Tuning the properties of black phosphorene such as structural, electronic and transport are explored via substitutional C-doping. We employed density functional theory calculations in combination with the non-equilibrium Green's function for modeling the systems. Our results revealed that substitutional C-doped phosphorene is energetically favorable and ruled by the exothermic process. We also found that C-doping induces a change of the electric properties, such as a semiconductor-to-metal transition for the most lower concentration and zig-zag C-wire. Furthermore, for an armchair C-wire at the highest concentration, the semiconductor character is kept, meanwhile direct-to-indirect transitions are observed in the band gap nature. The band structures show that there exists a dependence of the electronic charge transport with the directional character of the C-doped configuration. The findings demonstrate that the directional doping could play a key role for the conductance of a 2D platform.

Micellar suspensions of isolated single-walled carbon nanotubes were cross-linked, encasing the nanotubes in robust surfactant cages. These cages are surprisingly robust to changes in environmental conditions, allowing nanotubes to remain completely isolated, and thus fluoresce strongly, even when assembled into dense, solid films.

Single-molecule fluorescence spectroscopy was used to determine the electronic properties of individual single-walled carbon nanotubes. Carbon nanotube structure was determined simultaneously from Raman spectroscopy. Fluorescence spectra from individual nanotubes with identical structures have different emission energies and linewidths that likely arise from defects or the local environment. Unlike most other molecules studied to date, the fluorescence intensity or spectrum from a single nanotube unexpectedly did not fluctuate.

The electronic structure of SWNTs was investigated using the complementary techniques of single molecule photoluminescence spectroscopy and ultrafast optical spectroscopy. We found that photoexcited electrons in SWNTs isolated in surfactant micelles decay through many channels, exhibiting a range of decay times (~200 fs to ~ 120 ps). The magnitude of the longest-lived component in the ultrafast signal specifically depends on resonant excitation, thus suggesting that this lifetime corresponds to the band-edge relaxation time. Fluorescence spectra from single SWNTs are well described by a single, Lorentzian lineshape. However, nanotubes with identical structure fluoresce over a distribution of peak positions and line widths not observed in ensemble studies, caused by localized defects and electrostatic perturbations. Unlike for most other single molecules, for SWNTs the photoluminescence unexpectedly does not show any intensity or spectral fluctuations at 300K. This lack of photoluminescence intensity blinking or bleaching demonstrates that SWNTs have the potential to provide a stable, single molecule infrared photon source, allowing for the exciting possibility of single nanotube integrated photonic devices and biophotonic sensors.

The electronic structure of SWNTs was investigated using the complementary techniques of single molecule photoluminescence spectroscopy and ultrafast optical spectroscopy. We found that photoexcited electrons in SWNTs isolated in surfactant micelles decay through many channels exhibiting a range of decay times (~200 fs to ~ 120 ps). The magnitude of the longest-lived component in the ultrafast signal specifically depends on resonant excitation, thus suggesting that this lifetime corresponds to the band-edge relaxation time. Fluorescence spectra from single SWNTs are well described by a single, Lorentzian lineshape. However, nanotubes with identical structure fluoresce over a distribution of peak positions and line widths not observed in ensemble studies, caused by localized defects and electrostatic perturbations. Unlike for most other single molecules, for SWNTs the photoluminescence unexpectedly does not show any intensity or spectral fluctuations at 300K. This lack of photoluminescence intensity blinking or bleaching demonstrates that SWNTs have the potential to provide a stable, single molecule infrared photon source, allowing for the exciting possibility of single nanotube integrated photonic devices and biophotonic sensors.

The International Thermonuclear Experimental Reactor is an international scientific project with the aim of building a tokamak fusion reactor capable of producing at least 10 times more energy than that spent to sustain the reaction. In a tokamak the fusion reaction is magnetically confined and the toroidal field coil system plays a primary role in this confinement. Fusion for Energy, the European Domestic Agency for ITER, is responsible for the supply of 10 out the 19 toroidal field coils. Their procurement has been subdivided in three main work packages: the production of 70 radial plates (the structural components which will house the conductors), the manufacture of 10 winding packs (the core of the magnet) and cold test and insertion into the coil cases of 10 winding packs. The cold test/insertion work package presents significant technological challenges. These include the cold test of the winding packs 14 m high, 9 m wide and weighing 110 t, the welding and inspection of the 316 LN stainless steel coil case, with welded thicknesses of up to 144 mm accessible only from one side combined with the need to minimize the deformation during the welding process (more than 70 m of weld per coil and up to 90 passes to fill the chamfer) and the resin filling of the coil case after insertion of the winding pack (the total volume to be filled up is about one cubic meter per coil). From 2009 up to mid 2011, F4E has carried out an RD in this paper an overview of the results obtained is presented.

Single carbon nanotube fluorescence spectroscopy was used to determine the emission lineshape. Nanotube fluorescence unexpectedly lacks intensity or spectral fluctuations resulting in a stable, single infrared photon source for exciting applications in quantum optics.