Search results for "Conductor"

showing 10 items of 1270 documents

Potential application of some wide band gap materials for UV dosimetry

2005

Properties of some wide band gap materials–natural and CVD diamonds – have been studied for their potential application in UV dosimetry, using methods of optically stimulated luminescence and thermoluminescence. The observed properties are compared with those of the previously studied AlN ceramics. From the OSL excitation spectra, it follows that spectral sensitivity of the studied materials falls mainly into the UVC range, OSL and TL emission spectra are located within the visible light region, thus suitable for usual photodetectors. OSL stimulation spectra of the studied materials have a continuous character and are located in a broad visible/near infrared spectral region implying that th…

Spectral sensitivityOptically stimulated luminescencebusiness.industryChemistryWide-bandgap semiconductorOptoelectronicsPhotodetectorEmission spectrumbusinessThermoluminescenceSpectral lineVisible spectrumphysica status solidi (c)
researchProduct

Self-organization and nanostructural control in thin film heterojunctions.

2013

In spite of more than two-decades of studies of molecular self-assembly, the achievement of low cost, easy-to-implement and multi-parameter bottom-up approaches to address the supramolecular morphology in three-dimensional (3D) systems is still missing. In the particular case of molecular thin films, the 3D nanoscale morphology and function are crucial for both fundamental and applied research. Here we show how it is possible to tune the 3D film structure (domain size, branching, etc.) of thin film heterojunctions with nanoscale accuracy together with the modulation of their optoelectronic properties by employing an easy two-step approach. At first we prepared multi-planar heterojunctions w…

Spin coatingMaterials sciencebusiness.industryExcitonSupramolecular chemistryNanotechnologyHeterojunction3D nanopatterning thin films non-equilibrium exciton diffusion length optoelectronic properties bulk heterojunctionsSemiconductorGeneral Materials ScienceThin filmLuminescencebusinessNanoscopic scaleNanoscale
researchProduct

Effect of structural and compositional inhomogeneities on spin-glass transition in Hg1−x−yCrxMnySe crystals

2004

Abstract We report experimental results on the growth of Hg 1 −x−y Cr x Mn y Se crystals and their magnetic susceptibility χ ( T ) in dependence on the crystal structure and composition. It was found that the crystals with the Mn composition y =0.01–0.08 exhibit the spin-glass transition temperature T g =100–110 K. An increase of y value leads to the saturation of the χ max and T g characteristics in the composition ranges of y >0.06 and y >0.02, respectively. This phenomenon is explained as a result of phase-separated magnetic behavior caused by the formation of HgCr 2 Se 4 inclusions and textures.

Spin glassScanning electron microscopeChemistryTransition temperatureAnalytical chemistryCrystal structureMagnetic semiconductorCondensed Matter PhysicsMagnetic susceptibilityInorganic ChemistryNuclear magnetic resonanceMaterials ChemistryGlass transitionSaturation (magnetic)Journal of Crystal Growth
researchProduct

Research data supporting the paper "Tuning the effective spin-orbit coupling in molecular semiconductors"

2017

We here present the data underlying the paper "Tuning the effective spin-orbit coupling in molecular semiconductors" accepted at Nature Communications on 24 February 2017. For contributions of the authors to the data and experimental details, please refer to the original paper.

Spin orbit couplingOrganic semiconductorsSpintronicsMolecular semiconductorsOrganic spintronics
researchProduct

Nonlinear dependence on temperature and field of electron spin depolarization in GaAs semiconductors

2009

In this work the influence of temperature and drift conditions on the electron spin relaxation in lightly doped n-type GaAs bulk semiconductors is investigated. The electron transport, including the evolution of the spin polarization vector, is simulated by a Monte Carlo procedure which keeps into account all the possible scattering phenomena of the hot electrons in the medium. Electron-spin states in semiconductor structures relax by scattering with imperfections, other carriers and phonons. Spin relaxation lengths and times are computed through the D'yakonov-Perel process since this is the more relevant spin relaxation mechanism in the regime of interest (10 < T < 300 K). The decay of the…

Spin polarized transport in semiconductorMonte Carlo simulation.spin relaxation and scattering
researchProduct

Doping dependence of spin lifetime of drifting electrons in GaAs bulks

2010

We study the effect of the impurity density on lifetimes and relaxation lengths of electron spins in the presence of a static electric field in a n-type GaAs bulk. The transport of electrons and the spin dynamics are simulated by using a semiclassical Monte Carlo approach, which takes into account the intravalley scattering mechanisms of warm electrons in the semiconductor material. Spin relaxation is considered through the D'yakonov-Perel mechanism, which is the dominant mechanism in III-V semiconductors. The evolution of spin polarization is analyzed by computing the lifetimes and depolarization lengths as a function of the doping density in the range 10^{13} - 10^{16} cm^{-3}, for differ…

Spin polarized transport in semiconductorspin relaxation and scatteringMonte Carlo simulationSettore FIS/03 - Fisica Della Materia
researchProduct

Nonequilibrium electron spin relaxation in n-type doped GaAs sample

2019

Non-equilibrium electron spin relaxation in a n-type doped GaAs bulk semiconductor is investigated. We use a semiclassical Monte Carlo approach by considering multivalley spin dynamics of drifting electrons. Spin relaxation is considered through the D'yakonov-Perel mechanism, which is the dominant process in III-V semiconductors. An analytical expression for the inhomogeneous broadening of spin precession vector is derived by taking into account the effect of the electric field and the doping density. The inclusion of electron-electron scattering has the effect of increasing both the spin lifetime and the depolarization length. In particular, we find a non-monotonic trend with the maximum o…

Statistics and ProbabilityDYNAMICSMaterials scienceSettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciCondensed matter physicsDopingNon-equilibrium thermodynamicsStatistical and Nonlinear PhysicsCARRIERSSample (graphics)SEMICONDUCTORSTRANSPORTSettore FIS/03 - Fisica Della MateriaNOISESPINTRONICSRelaxation (physics)SCATTERINGStatistics Probability and UncertaintySILICONDRIFTING ELECTRONSPATTERN-FORMATION
researchProduct

Experimental investigations of local stochastic resistive switching in yttria stabilized zirconia film on a conductive substrate

2020

We report on the results of the experimental investigations of the local resistive switching (RS) in the contact of a conductive atomic force microscope (CAFM) probe to a nanometer-thick yttria stabilized zirconia (YSZ) film on a conductive substrate under a Gaussian noise voltage applied between the probe and the substrate. The virtual memristor was found to switch randomly between the low resistance state and the high resistance state as a random telegraph signal (RTS). The potential profile of the virtual memristor calculated from its response to the Gaussian white noise shows two local minima, which is peculiar of a bistable nonlinear system.

Statistics and ProbabilityMaterials scienceDiffusionStatistical and Nonlinear Physicsbrownian motionSubstrate (printing)Diffusionstochastic particle dynamicResistive switchingfluctuation phenomenaStatistics Probability and UncertaintyComposite materialElectrical conductorYttria-stabilized zirconiaBrownian motion
researchProduct

Relaxation of Electron Spin during High-Field Transport in GaAs Bulk

2011

A semiclassical Monte Carlo approach is adopted to study the multivalley spin depolarization of drifting electrons in a doped n-type GaAs bulk semiconductor, in a wide range of lattice temperature ($40<T_L<300$ K) and doping density ($10^{13}<n<10^{16}$cm$^{-3}$). The decay of the initial non-equilibrium spin polarization of the conduction electrons is investigated as a function of the amplitude of the driving static electric field, ranging between 0.1 and 6 kV/cm, by considering the spin dynamics of electrons in both the $\Gamma$ and the upper valleys of the semiconductor. Doping density considerably affects spin relaxation at low temperature and weak intensity of the driving electric fiel…

Statistics and ProbabilityMaterials scienceField (physics)FOS: Physical sciencesElectronSettore FIS/03 - Fisica Della MateriaCondensed Matter::Materials ScienceElectric fieldMesoscale and Nanoscale Physics (cond-mat.mes-hall)Spin (physics)Condensed Matter - Statistical MechanicsCondensed matter physicsSpin polarizationStatistical Mechanics (cond-mat.stat-mech)Condensed Matter - Mesoscale and Nanoscale Physicsbusiness.industryDopingRelaxation (NMR)Statistical and Nonlinear Physicsdriven diffusive systems (theory) stochastic particle dynamics (theory) transport processes/heat transfer (theory) Boltzmann equationCondensed Matter::Mesoscopic Systems and Quantum Hall EffectSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)SemiconductorCondensed Matter::Strongly Correlated ElectronsStatistics Probability and Uncertaintybusiness
researchProduct

The Importance of Electronic Dimensionality in Multiorbital Radical Conductors.

2019

The exceptional performance of oxobenzene-bridged bis-1,2,3-dithiazolyls 6 as single-component neutral radical conductors arises from the presence of a low-lying π-lowest unoccupied molecular orbital, which reduces the potential barrier to charge transport and increases the kinetic stabilization energy of the metallic state. As part of ongoing efforts to modify the solid-state structures and transport properties of these so-called multiorbital materials, we report the preparation and characterization of the acetoxy, methoxy, and thiomethyl derivatives 6 (R = OAc, OMe, SMe). The crystal structures are based on ribbonlike arrays of radicals laced together by S···N' and S···O' secondary bondin…

Steric effects010405 organic chemistryChemistryRadicalElectronic structureCrystal structuremultiorbital radical conductors010402 general chemistryvapaat radikaalitkiteet01 natural sciencessähkönjohtavuus0104 chemical sciencesInorganic ChemistryCrystallographyelectronic dimensionalityElectronic effectAntiferromagnetismMolecular orbitalDensity functional theoryPhysical and Theoretical Chemistryta116Inorganic chemistry
researchProduct