A5031686886- Laser-induced spectroscopy and plasma
- Laser Material Processing Techniques
- Laser-Ablation Synthesis of Nanoparticles
- Diamond and Carbon-based Materials Research
- Silicon Nanostructures and Photoluminescence
- ZnO doping and properties
- Nonlinear Optical Materials Studies
- Ion-surface interactions and analysis
- Laser Design and Applications
- Thin-Film Transistor Technologies
- Quantum Dots Synthesis And Properties
- Ocular and Laser Science Research
- Surface Roughness and Optical Measurements
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Random lasers and scattering media
- Copper-based nanomaterials and applications
- Solid State Laser Technologies
- Atomic and Molecular Physics
- Semiconductor materials and devices
- Laser-Matter Interactions and Applications
- Metal and Thin Film Mechanics
- High-Temperature Coating Behaviors
- Plasma Diagnostics and Applications
- Metallic Glasses and Amorphous Alloys
Czech Academy of Sciences, Institute of Physics
2023-2024
Centre National de la Recherche Scientifique
2004-2014
Aix-Marseille Université
1992-2014
Centre Interdisciplinaire de Nanoscience de Marseille
2004-2014
Université de Limoges
2010
Imperial College London
2010
Institut de Neurobiologie de la Méditerranée
1997-2008
Centre d’Immunologie de Marseille-Luminy
1989-2006
Institut de Recherche Dupuy de Lôme
1985-2003
Institut de Recherche sur les Phénomènes Hors Équilibre
2000
We report a photoluminescence study of silicon nanoclusters produced by laser ablation. It was found that varying the preparation parameters it possible to change mean cluster size in range 1–5 nm. Within this variation, band shifts wide spectral region from near ultraviolet infrared. This size-dependent Si is consistent with quantum confinement effect. The observed influence oxidation on luminescence properties also supports interpretation. proposed discrete model which supposes position...
This work presents hybrid bulk heterojunction solar cells based on dye-sensitized zinc oxide (ZnO) nanorods blended with poly(3-hexylthiophene) (P3HT). Tetra(4-carboxyphenyl)porphyrin (TCPP) molecules were grafted onto the surface of ZnO to enlarge absorption spectrum blend. We demonstrate that additional bands in external quantum efficiency (EQE) spectra corresponding Soret and Q-band can already been observed at very low dye concentration surface. Therefore, direct grafting TCPP leads...
Nonlinear optical conversion is studied in thin films of wide-bandgap materials. Very high efficiency to the third-harmonic radiation achieved for an unamplified femtosecond Cr4+:forsterite laser a submicron-thick film nanocrystalline ZnO pulsed-laser-deposited on fused silica substrate.
Using various band-gap materials and tightly focused femtosecond laser pulses with wavelengths in the range 1200--2200 nm, we show that nonlinear absorption is independent of wavelength except for narrow gap semiconductor materials. This observation corresponds to a transition between multiphoton ionization tunnel an adiabaticity parameter about 3, which compares favorably Keldysh predictions. Our results indicate long must open up alternative pulse shortening ultraprecision optical...
Laser ablation from a binary target into diluted gas background is studied by means of Monte Carlo simulation. The influence the ambient on spatial and mean energy distribution particles deposited at distant detector considered. Thermalization particles, random scattering effect backscattering were observed. Considerable modification film thickness profiles due to collisions ablated with shown. increase pressure was found affect stoichiometry backscattered particles. study particular...
The physical phenomena involved during three-dimensional axisymmetric laser-induced plasma expansion into background gas are numerically studied. For this purpose, a multispecies hydrodynamic model is developed which considers the effects of mass and ambipolar diffusions, thermal conduction, viscosity, nonequilibrium conditions for ionization. This applied to describe quantitatively Si plume Ar or He gases. It shown that mechanism depends critically on both pressure gas. shock front found be...
Thin film of ZnO nanoparticles with dimension about 5–10nm were fabricated by the pulsed laser ablation method. By using a femtosecond beam at 700nm to pump micrometer-thick films authors observed two-photon-induced lasing 385nm. Experimentally obtained dependence threshold on excitation spot radius r0 is closer (1∕r02) than (1∕r0), thus suggesting efficiency feedback scattering-random lasing. The experimental data nonlinear transmission wavelength pumping are presented.
In spite of the fact that more than five decades have passed since invention laser, some topics laser-matter interaction still remain incompletely studied. One such is plasma impact on overall phenomenon and its particular features, including influence laser-excited re-radiation, back flux energetic species, massive material redeposition, surface quality processing efficiency. this paper, we analyze different aspects, which go beyond a simple consideration well-known effect shielding laser...
Monte Carlo simulation is used to study the role of chemical reactions in gas flow particles laser desorbed from target into a vacuum. The influence recombination and dissociation processes on properties considered. It was found that have significant effect composition desorption jet angular mean energy distributions particles. these phenomena particular interest for understanding process thin film deposition by pulsed ablation.
An analytical thermal model of ultraviolet (UV) laser ablation has been proposed. The approximation used to describe the absorption incident beam in excimer induced plasma, for case single-photon σeff(t)=const. (where σeff is effective cross section ejected species) gives results on UV kinetics. In particular, changing (increasing or decreasing) slope curve etch depth, z, versus logarithmic fluence, ln E, explained.
We describe a simple way of producing adherent metal films (Cu or Ni) on insulator surfaces [SiO2, glass, polyphenylquinoxaline (PPQ), an insulating polymer] by electroless growth thermally activated palladium acetylacetonate [Pd(acac)2] seeding layer. Using this process, we produced tiny patterns insulators localized laser pyrolysis (using either pulsed Cu vapor cw Ar+ laser) the spun-on A tensile stress test applied to Ni deposit SiO2 reveals bonding strengths as high 2 N/mm2. The...
Silicon oxide, oxynitride, and nitride films are deposited, at low temperature (≤450 °C) by pulsed ArF excimer laser ablation from silicon, silicon monoxide, fused silica, targets, performed under vacuum in an oxygen atmosphere. The specific influence of fluence, target materials, substrate temperature, pressure on the composition final properties SiOxNy grown layers is investigated using various complementary experiments such as infrared optical absorption, Rutherford backscattering, Auger...
We report investigations of a space-time structure the electric field laser plasma from solid target. An ArF excimer with an intensity I≅108 W/cm2 was used to produce on various targets placed in air at atmospheric pressure. A strong difference both amplitude (by more than 1–2 orders magnitude) and for conductive dielectric has been observed. The distribution target found correspond dipole configuration charges plasma, while quadrupole revealed. Possible explanations applications observed...