A5044490993- Luminescence Properties of Advanced Materials
- Glass properties and applications
- Rare-earth and actinide compounds
- Nuclear materials and radiation effects
- Iron-based superconductors research
- Photonic Crystal and Fiber Optics
- Chalcogenide Semiconductor Thin Films
- Radioactive element chemistry and processing
- Perovskite Materials and Applications
- Silicon and Solar Cell Technologies
- Optical Network Technologies
- Solid-state spectroscopy and crystallography
- solar cell performance optimization
- Dielectric materials and actuators
- Chemical Synthesis and Characterization
- Physics of Superconductivity and Magnetism
- Nuclear Materials and Properties
- Mineralogy and Gemology Studies
- Nuclear reactor physics and engineering
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Magnetic Properties of Alloys
- Solid State Laser Technologies
- Analytical Chemistry and Sensors
- Advanced Sensor and Energy Harvesting Materials
École Polytechnique
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2025
Institut Rayonnement-Matière de Saclay
2017-2023
CEA Paris-Saclay
2016-2023
Laboratoire des Solides Irradiés
2016-2023
Université Claude Bernard Lyon 1
2023
University of Latvia
2023
Laboratoire de Physique et Chimie des Nano-Objets
2022
Université Paris-Saclay
2016-2021
A highly anisotropic superconducting gap is found in single crystals of FeSe by studying the London penetration depth, $\Delta \lambda$, measured down to 50 mK samples before and after 2.5 MeV electron irradiation. The minimum increases with introduced point - like disorder, indicating absence symmetry imposed nodes. Surprisingly, transition temperature, $T_c$, \textit{increases} 0.4 K from $T_{c0} \approx$ 8.8 while structural $T_s$, \textit{decreases} 0.9 $T_{s0} \approx$91.2 We discuss...
This paper presents a systematic experimental study of the impact disorder induced by electron irradiation on superconducting phase Dirac semimetal PdTe2. Using recently derived generalized version Anderson theorem, authors obtain quantitative constraints pairing state. leaves an unconventional as most natural candidate order.
Abstract To understand the influence of proton irradiation on lattice‐matched GaInP/GaAs/Ge triple junction (TJ) solar cells under low intensity, temperature (LILT) conditions, we investigated electrical behaviors top, middle, and bottom component together with TJ these conditions. Proton irradiations energies 1 MeV fluences ranging from 2 × 10 to 1.6 12 cm −2 were performed at temperatures 100 300 K. Our study reveals that any 3 subcells can become current limiting cell in cell, depending...
Ytterbium doped fiber lasers are known to be impacted by the creation of color centers during lasing so called photodarkening. This defect was investigated in a spectroscopic point view, showing presence thulium traces (ppb) ytterbium fiber. Moreover, this contamination exhibit luminescence UV range under 976 nm excitation ytterbium-doped In adding more an it shown that strongly impact defects process, involved
An experimental study on how to reduce the content of singly ionized zinc vacancy (V − Zn ) in ZnGeP 2 crystals improve their optical quality is presented. Their electron paramagnetic resonance signal has been studied samples treated different ways. The data provide a scheme reductions that can be obtained by methods or combinations. adding Sn during synthesis phase helps production large‐size single and reduction V content. Thermal treatment irradiation are then needed for further...
Manufacture fiber amplifiers and lasers in a versatile cost effective way while controlling rare-earths chemical environment becomes real technology differentiator. A MCVD compatible Nanoparticle Doping Process has been developed to master with higher accuracy rare earth amplifier ytterbium laser fibers. Improved doped erbium fibers C-band gain shape were obtained much less aluminum content unprecedented low background attenuation losses. This process should better show its merits high power...
Ever demanding network implementations brought new requirements to be addressed offer cost effective and power efficient solutions with smaller footprints. This general trend together the constant need improve L-band optical amplification efficiency account for renewed interest on highly doped Erbium fibers. fiber amplifiers (EDFAs) performance degradation Er<sup>3+</sup> concentration increase has extensively been studied1 is attributed additional losses due energy transfers between...
The degradation of solar cells under irradiation by high energy particles (electrons, protons) is the consequence introduction defects trapping minority carriers, which are then not collected junction. However, at low temperature, located in space charge region can also induce a tunneling current that results an apparent decreases maximum power. produced this depend on since concentration created usually temperature dependent, and be larger than associated with carrier recombination. For...
High purity synthetic silica glass (Suprasil F300) samples were densified by Pressure/High Temperature (HP-HT) using three different pressure/temperature/duration values. Their relaxation process was studied applying 2.5 MeV electron irradiation with doses varying from 1 MGy up to 11 GGy. At very high dose (11 GGy), all the exhibit same density value (∼2.26 g/cm3) regardless of densification conditions, referring an equilibrium known as amorphous metamict phase. In detail, HP-HT...
This Letter relates the clear evidence of Yb2+ formation under 2.5 MeV electron irradiation in optical fiber preforms showing a darkening core. We thus detected by situ photoluminescence measurements green emission divalent 355 nm excitation. Moreover, we showed existence two types ion species with different stabilities. demonstrated that radiodarkening mechanism is based on pair association aluminum oxygen hole center point defects.
Piezoelectric PVDF polymer thin films are nanostructured by swift heavy ion beam resulting in nanoporous structures. The nanocylindars then partially filled with Ni(0) order to create a composite of higher dielectric permittivity. In second step, the is irradiated electron beam, induce chain scissions matrix and render it more flexible. It found that e-beam irradiation does not affect remanent polarization up than 1MGy. energy harvesting properties optimized maximum for 1MGy irradiation,...
Abstract This study aims to learn more about the structure of densified silica with focus on metamict-like phase (density = 2.26 g/cm 3 ) by examining formation E’ point defects and interstitial molecular oxygen O 2 2.5 MeV electron irradiation. High-dose (11 GGy) irradiation creates a large amount , which is destroyed upon subsequent additional lower-dose The cathodoluminescence (CL) data indicate that from peroxy linkages Si–O–O–Si in network strongly dependent intertetrahedral void sizes....
In 2009, we introduced a new doping concept involving Al<sub>2</sub>O<sub>3</sub>/rare-earth nanoparticles (NP) in MCVD-compatible process finding potential applications Erbium-, Ytterbium- or Erbium-Ytterbium-doped fiber amplifiers and lasers.<sup>1</sup> This approach, motivated by the need for increased efficiencies improved attributes, is characterized ability to control rare-earth ion environment independently from core composition. The NP matrix can therefore be viewed as an optimized...
Low-temperature (22 K) irradiation with 2.5-MeV electrons, creating point defects affecting elastic scattering, was used to study the competition between stripe ${\mathrm{C}}_{2}$ and tetragonal ${\mathrm{C}}_{4}$ antiferromagnetic phases which exist in a narrow doping range around $x=0.25$ hole-doped ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{K}}_{x}{\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$. In nearby compositions outside of this range, at $x=0.22$ $x=0.19$, temperatures both concomitant...
Abstract Understanding the role of defects in hybrid organic inorganic perovskites (HOIPs) is critically important to engineer stability and performance photovoltaic devices based on HOIPs. Recent reports multi-cation compositions general formula (A 1 ,A 2 3 4 )Pb(X ,X ) , where A sites can be occupied by a distribution 2–4 metallic/organic cations X with halide anions have shown stabilization effects against well-known methyl ammonium lead triiodide (CH NH PbI ), although underlying...