Search results for "Toe"
showing 10 items of 3824 documents
Photoinduced mass transfer in amorphous As 2 S 3 films
2011
The surface relief grating formation in amorphous As2S3 films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
The Amorphous Semiconductor Schottky Barrier Approach to Study the Electronic Properties of Anodic Films on Ti
2017
A detailed study of the electronic properties of thin (>20 nm) anodic TiO2 potentiostatically grown on titanium in two different solutions is presented. The results show that the nature of the anodizing solution affects the electronic properties of the anodic film and, more specifically, the density of electronic states (DOS) distribution. Different DOS were derived from the experimental data analyzed according to the theory of amorphous semiconductor (a-SC) Schottky barrier. It is shown that the usual non-linear and frequency dependent Mott-Schottky plots are in agreement with expected theoretical behavior of a-SC Schottky barrier.
Cu-substituted lanthanum ferrite perovskites: Preparation, characterization and photocatalytic activity in gas-solid regime under simulated solar lig…
2016
Lanthanum orthoferrites LaFeO3 nanopowders doped with 20 mol% of Sr and 0-10-20 mol% of Cu were prepared by citrate auto-combustion synthesis and investigated in terms of crystal structure, morphology, surface area and optical properties by using several characterization techniques. The band gap energy values were found to range from 2.35 eV for LaFeO3 to 1.86 eV for the samples with the highest content of copper, this trend reflects the decrease of the particle size. All powders showed photocurrent response, the highest photocurrent was obtained for undoped orthoferrite calcined at 600°C. Their physical-chemical properties were related to photoelectrochemical behaviour. The the position of…
Low-temperature growth of n ++-GaN by metalorganic chemical vapor deposition to achieve low-resistivity tunnel junctions on blue light emitting diodes
2018
We report on low-resistivity GaN tunnel junctions (TJ) on blue light-emitting diodes (LEDs). Si-doped n ++-GaN layers are grown by metalorganic chemical vapor deposition directly on LED epiwafers. Low growth temperature (<800 °C) was used to hinder Mg-passivation by hydrogen in the p ++-GaN top surface. This allows achieving low-resistivity TJs without the need for post-growth Mg activation. TJs are further improved by inserting a 5 nm thick In0.15Ga0.85N interlayer (IL) within the GaN TJ thanks to piezoelectric polarization induced band bending. Eventually, the impact of InGaN IL on the internal quantum efficiency of blue LEDs is discussed.
Effects of heat treatments on the properties of copper phthalocyanine films deposited by glow-discharge-induced sublimation
2006
Copper phthalocyanine films have been deposited by glow-discharge-induced sublimation. The films have undergone postdeposition heat treatments in air at 250 and 290 °C for different times, ranging from 30 min to 14 h. The properties of as-deposited and heated films have been investigated by different techniques in order to determine the effects of heat treatments on the film properties. Fourier transform infrared analysis and UV−visible optical absorption analysis point out a gradual evolution of the film structure from a mixture of α and β polymorphs to the only β polymorph in the sample heated at 290 °C for 14 h. A pronounced decrease of carbon and nitrogen atomic percentages against an o…
The ultrafast dynamics and conductivity of photoexcited graphene at different Fermi energies
2017
The ultrafast dynamics and conductivity of photoexcited graphene can be explained using solely electronic effects.
Solution-processed transparent ferroelectric nylon thin films
2019
We have developed a method to solution process strongly hydrogen-bonded odd nylons into ferroelectric thin films.
Large, Highly Modular Narrow-Gap Electrolytic Flow Cell and Application in Dehydrogenative Cross-Coupling of Phenols
2019
The successive scale-up of electrochemical reactions is crucial with regard to the implementation of technical electro-organic syntheses. Therefore, we developed a scalable modular parallel-plate e...
Comparison of conventional and dense dispersion managed systems for 160 Gb/s transmissions
2006
International audience; In this paper, we carry out, by numerical simulations and experiments on recirculating loop.. a comparative analysis of the performances of two types of dispersion management techniques for 160 Gb/s transmission systems, which correspond to short-period dispersion maps (dense dispersion management) and long-period dispersion maps (conventional dispersion management), respectively. We show that the dense dispersion management system suffers performance degradation by the effects of polarization mode dispersion (PMD) and fiber splicing losses, in a more dramatic manner than in the system with long-period map. We experimentally find that, at constant PMD, dense dispersi…
Wavelength-selective directional coupling with dielectric-loaded plasmonic waveguides
2009
International audience; We consider wavelength-selective splitting of radiation using directional couplers (DCs) formed by dielectric-loaded surface-plasmon-polariton waveguides (DLSPPWs). The DCs were fabricated by depositing subwavelength-sized polymer ridges on a gold film using large-scale UV photolithography and characterized at telecommunications wavelengths with near-field microscopy. We demonstrate a DLSPPW-based 45-mu m-long DC comprising 3 mu m offset S bends and 25-mu m-long parallel waveguides that changes from the "through" state at 1500 nm to 3 dB splitting at 1600 nm, and show that a 50.5-mu m-long DC should enable complete separation of the radiation channels at 1400 and 162…