Green LED as an Effective Light Source for Curing Acrylate-Based Dental Resins in Combination with Irgacure 784

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Stimulated structural changes of Se in nanolayered composite films

International audienceAmorphous selenium (a-Se) is the simplest model material for investigation of the well-known photoinduced structural and optical transformations in amorphous chalcogenides. Since a lot of parameters and characteristics of materials essentially change at nanoscale, we applied nanostructuring to a -Se in nanomultilayers, obtained by pulsed laser deposition. The enhancement of photo- and thermally-induced crystallization was observed in a-Se/aluminosilicate nanomultilayers due to the initially heterogeneous state of Se in such samples, in comparison with single a -Se layers

Application of gold nanoparticles–epoxy surface nanocomposites for controlling hotspot density on a large surface area for SERS applications

The applicability of a novel gold–epoxysurface nanocomposite for surface-enhanced Raman scattering (SERS) is investigated. The nanocomposite consists of ellipsoidal nanoparticles in a hexagonal arrangement, where the average particle diameter (D0) and interparticle gap (D) can be controlled in the 0.15–1.00 (D/D0) range on a large surface area (several cm 2). Numerical simulations were used to estimate the SERS enhancement factors of substrates with five different particle arrangements. The fabricated substrates’ surface was functionalized with 20 base-pair long double-stranded DNA molecules and the intensities of the characteristic Raman peaks related to DNA were used to quantify the substrate performance. It was proved that by optimizing the fabrication parameters and maximizing the interparticle coupling, the characteristic Raman intensities could be increased by more than 2.5 orders of magnitude

Surface patterning in Ge-Se amorphous layers

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Fabrication and properties of luminescence polymer composites with erbium/ytterbium oxides and gold nanoparticles

Rare-earth-doped optical materials are important for light sources in optoelectronics, as well as for efficient optical amplification elements and other elements of photonics. On the basis of the previously developed method of anhydrous, low-temperature synthesis of Er/Yb oxides from their chlorides we fabricated proper nanoparticles with defined parameters and used them for the development of optically transparent, luminescent polymer nanocomposite with low optical scattering, suitable for direct, light-induced formation of photonic elements. Introduction of preformed gold nanoparticles in such a nanocomposite was also performed and an enhancement of luminescence due to the influence of plasmon effects was detected

Engineering SERS Properties of Silicon Nanotrees at the Nanoscale

Large specific surface area nanostructures are desirable in a wide range of sensing applications due to their longer light-trapping path and increased absorption. Engineering of the specific nanotree structure which possesses a high branch density turned out to be challenging from the experimental point of view, and certainly not adequately explored. This paper shows how to design substrates with a silicon nanotree structure for surface-enhanced Raman spectroscopy (SERS) applications. Silicon nanotrees were synthesized by a Ag-Au nanocluster-catalyzed low- pressure chemical vapor deposition method (LPCVD). By the presented approaches, it is possible to manipulate branches’ number, length and thickness. The synthesized nanostructures are flexible after immersion in water which improves SERS performance. The amount of sputtered metal played a key role in preserving the flexibility of the nanotree structure. The obtained substrates with highly fractal nanostructure were tested on 4- mercaptophenylboronic acid (MPBA) to match the optimal SERS parameters. The silicon nanotrees fabrication, and particularly obtained SERS substrates plated with Ag and Au nanoparticles, demonstrated good features and a promising approach for further sensor development