Search results for "Applied Physics"
showing 10 items of 1226 documents
In situ study of the sintering of a lead phosphovanadate in an Environmental Scanning Electron Microscope
2011
cited By 3; International audience; The in situ sintering of a powder of Pb3(VO4) 1.6(PO4)0.4 composition was performed in an Environmental Scanning Electron Microscope. The electric current induced by the electron beam was found to reduce the effective temperature of sintering as well as to accelerate the kinetics of shrinkage of a cluster composed of sub-micrometric grains of material. The presence of the residual current flow in the cluster during observation for in situ experiments helps to reduce the apparent sintering temperatures from 50 to 150 °C compared to conventional heating conditions without current. © 2011 Elsevier B.V. All rights reserved.
Removing Leakage and Surface Recombination in Planar Perovskite Solar Cells
2019
Thin-film solar cells suffer from various types of recombination, of which leakage current usually dominates at lower voltages. Herein, we demonstrate first a three-order reduction of the shunt loss mechanism in planar methylammonium lead iodide perovskite solar cells by replacing the commonly used hole transport layer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with a better hole-selective polyarylamine. As a result, these cells exhibit superior operation under reduced light conditions, which we demonstrate for the extreme case of moonlight irradiance, at which open-circuit voltages of 530 mV can still be obtained. By the shunt removal we also observe the VOC to dro…
Optimization of a hot-cavity type resonant ionization laser ion source
2015
TuePS05; International audience; Resonant Ionization Laser Ion Source (RILIS) is nowadays an important technique in many RadioactiveIon Beam (RIB) facilities for its reliability and ability to ionize efficiently and element selectively.Grand Accélérateur National d’Ions Lourds (GANIL) Ion Source using Electron Laser Excitation(GISELE) is an off-line test bench for RILIS developed to study a fully operational resonant laserion source at GANIL facility. The ion source body has been designed as a modular system toinvestigate different experimental approaches by varying the design parameters, to develop the futureon-line laser ion source. The aim of this project is to determine the best technic…
Heavy-Ion Radiation Impact on a 4Mb FRAM under Different Test Conditions
2015
The impact of heavy-ions on commercial Ferroelectric Memories (FRAMs) is analyzed. The influence of different test modes (static and dynamic) on this memory is investigated. Static test results show that the memory is prone to temporary effects occurring in the peripheral circuitry. Dynamic tests results show a high sensitivity of this memory to heavy-ions.
Magnetic field-controlled 0−π transitions and their experimental signatures in superconductor-ferromagnet-superconductor junctions
2019
Superconductor-ferromagnet-superconductor Josephson junctions are known to exist in the $0$ and $\pi$ states with the transitions between them controlled by the temperature and ferromagnetic interlayer thickness. We demonstrate that these transitions can be controlled also by the external magnetic field directed perpendicular to the layers. By varying the ratio of diffusion coefficients in superconducting and ferromagnetic layers, these field-controlled transitions can be made detectable for arbitrary large value of the exchange energy in the ferromagnet. We also show that the $0$-$\pi$ transitions in the perpendicular field can be observed as the specific features of the flux-flow conducti…
Comparison of downscaling techniques for high resolution soil moisture mapping
2017
Soil moisture impacts exchanges of water, energy and carbon fluxes between the land surface and the atmosphere. Passive microwave remote sensing at L-band can capture spatial and temporal patterns of soil moisture in the landscape. Both ESA and NASA have launched L-band radiometers, in the form of the SMOS and SMAP satellites respectively, to monitor soil moisture globally, every 3-day at about 40 km resolution. However, their coarse scale restricts the range of applications. While SMAP included an L-band radar to downscale the radiometer soil moisture to 9 km, the radar failed after 3 months and this initial approach is not applicable to developing a consistent long term soil moisture prod…
Eu3+ ion distribution in oxyfluoride glass nanocomposites
2019
The authors are grateful to Dr. Andris Fedotovs for photography of the samples. This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335.
Experimental characterization of Ruthenium-based Dye Sensitized Solar Cells and study of light-soaking effect impact on performance
2016
In this paper, we present an experimental investigation on the performance of Ruthenium-based Dye Sensitized Solar Cells (DSSCs) at different irradiance levels, incident wavelengths and hours of illumination. In particular, the measurements have been aimed at studying the performance variation due to light soaking effect since this phenomenon has noteworthy practical implications, such as stability tests of DSSCs. Our results show that the short circuit current density, the open circuit voltage and the conversion efficiency η increase with the hours of light soaking. Finally, the observed phenomenon is reversible, and thus the performance decreases again when the cell is kept in the dark.
Magnon and Phonon Excitations in Nanosized NiO
2019
Single-crystal, microcrystalline and nanocrystalline nickel oxides (NiO) have been studied by Raman spectroscopy. A new band at ~200 cm-1 and TO-LO splitting of the band at 350–650 cm-1 have been found in the spectra of single-crystals NiO(100), NiO(110) and NiO(111). The Raman spectra of microcrystalline (1500 nm) and nanocrystalline (13–100 nm) NiO resemble those of the single crystals. They all contain the two-magnon band at 1500 cm-1, indicating that the oxides remain at room temperature in the antiferromagnetic phase. Besides, a new sharp Raman band has been observed at 500 cm-1 in nanocrystalline NiO. Its temperature dependence suggests the magnetic origin of the band, possibly associ…
Layer-dependent mechanical properties and enhanced plasticity in the van der Waals chromium trihalide magnets
2020
The mechanical properties of magnetic materials are instrumental for the development of the magnetoelastic theory and the optimization of strain-modulated magnetic devices. In particular, two-dimensional (2D) magnets hold promise to enlarge these concepts into the realm of low-dimensional physics and ultrathin devices. However, no experimental study on the intrinsic mechanical properties of the archetypal 2D magnet family of the chromium trihalides has thus far been performed. Here, we report the room temperature layer-dependent mechanical properties of atomically thin CrI3 and CrCl3, finding that bilayers of CrI3 and CrCl3 have Young's moduli of 62.1 GPa and 43.4 GPa, with the highest sust…