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Photon Energy Range (photon + energy_range)

Distribution by Scientific Domains
Physics and Astronomy83%

Selected Abstracts

Growth and optical characterization of Cd1- xBexSe and Cd1- xMgxSe crystals

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 4-5 2005
F. Firszt
Abstract Cd1- xBexSe and Cd1- xMgxSe solid solutions were grown from the melt by the high pressure Bridgman method. Optical, luminescence and photothermal properties of these materials were investigated. Spectroscopic ellipsometry was applied for determination of the spectral dependence of the complex dielectric function (E) and refractive index n(E) at room temperature in the photon energy range 0.75-6.5 eV for samples with optic axis (c-axis) perpendicular to the air-sample interface. The critical point (CP) parameters for E0 and E1 transitions were determined using a standard excitonic CP function to fit the numerically calculated differential spectra ,2,2/,E2. The dispersion of the refractive index of the alloys was modelled using a Sellmeier-type relation. The values of fundamental and exciton band-gap energies were estimated from the ellipsometric and photoluminescence measurements. The origin of luminescence in Cd1- xBexSe and Cd1- xMgxSe was discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

First results from the Canadian SGM beamline at SRC

JOURNAL OF SYNCHROTRON RADIATION, Issue 5 2000
B. W. Yates
The first experimental results obtained from the Canadian SGM beamline at SRC (Synchrotron Radiation Centre, University of Wisconsin-Madison, USA) are reported. The beamline is based on the Dragon-type design, with a constant deviation angle, using photons from a second-generation bending-magnet light source. The medium-energy grating on this beamline covers a photon energy range from 240 to 700,eV, with a ruling density of 600,lines,mm,1. A maximum resolving power of ,10000 is achieved at a photon energy of ,400,eV. Gas-phase absorption spectra collected at the N, O and C K -edges are presented to demonstrate the excellent performance of this beamline. High-resolution absorption spectra of some C- and Ti-containing solid-state samples are also reported. [source]

Optical anisotropy of A - and M -plane InN grown on free-standing GaN substrates

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2010
P. Schley
Abstract Wurtzite A - and M -plane InN films were grown by molecular beam epitaxy (MBE) on free-standing GaN substrates. Spectroscopic ellipsometry (SE) in the photon energy range from 0.56 up to 15,eV was applied in order to determine the ordinary and extraordinary complex dielectric function (DF) of InN. A distinct optical anisotropy was found over the whole energy range. The extraordinary absorption edge in comparison to the ordinary one is shifted to higher energies confirming previous studies. The investigations in the upper vacuum-ultraviolet (VUV) spectral range (9.5,15,eV) yielded transition energies for four critical points (CPs) of the band structure (BS) which have not been observed so far. [source]

The study of structural changes of amorphous Ge2Sb2Te5 films after annealing by optical absorption spectroscopy

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2010
Tamihiro Gotoh
Abstract Optical absorption spectra of post-annealed Ge2Sb2Te5 films were measured in the photon energy range from 0.5 to 3.5,eV. Optical absorption edge and Urbach slope parameter changed slightly with increase in annealing temperature and then abrupt changes occurred at around crystallization temperature. The band gaps of amorphous and cubic Ge2Sb2Te5 are 0.74 and 0.54,eV, respectively. The spectroscopic method is demonstrated to be suitable for evaluation of structural disorder and crystalline composition in phase-change materials. [source]

IR-VIS-UV ellipsometry, XRD and AES investigation of In/Cu and In/Pd thin films

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2008
A. A. Wronkowska
Abstract Optical and compositional properties of In, In/Pd and Pd/In/Pd thin films evaporated on Cu and SiO2 substrates in vacuum were investigated by means of X-ray diffractometry, Auger electron spectroscopy and spectroscopic ellipsometry methods. Auger depth profile studies were performed in order to determine the composition of InCu and InPd structures. In both systems interdiffusion of metals was detected at room temperature. The XRD patterns indicated formation of CuIn2 and PdIn3 phases in the samples. Optical properties of the composite layers containing intermetallic phases were derived from ellipsometric quantities , and , measured in the photon energy range 0.1-6.0 eV at different angles of incidence using suitable multilayer models for the examined samples. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Characterisation of Cd1,x,yZnxBeySe crystals by spectroscopic ellipsometry and luminescence

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2006
A. A. Wronkowska
Abstract Optical and luminescence properties of Cd1,x,yZnxBeySe solid solutions grown in the composition range 0 < x < 0.15 and 0 < y < 0.30 by the high pressure Bridgman method are reported. Spectroscopic ellipsometry was employed for determination of spectral dependence of the complex dielectric function ,(E), refractive index n(E) and absorption coefficient ,(E) in the photon energy range 0.75,6.0 eV. The dispersion of the refractive index of the alloys was modelled using a Sellmeier-type relation. The excitonic band-gap energies were estimated from the ellipsometric and photoluminescence measurements. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]