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T Schmiedel - One of the best experts on this subject based on the ideXlab platform.
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pressure dependence of the Band Gap Energy and the conduction Band mass for an n type ingaas gaas strained single quantum well
Physica E-low-dimensional Systems & Nanostructures, 1998Co-Authors: E D Jones, S W Tozer, T SchmiedelAbstract:Abstract We report the measurement of the pressure dependence for the Band-Gap Energy Eg and conduction-Band mass mc for an 80 A-wide n-type In0.20Ga0.80As/GaAs strained-single-quantum well at 4.2 K for pressures between 0 and 35 kbar and fields up to 30 T. The Band-Gap Energy Eg, at each pressure, was determined by extrapolating the magnetoluminescence “fan-diagram” to zero magnetic field. The pressure dependence of the Band-Gap Energy was found to be quadratic with a linear term of about 10.3 meV/kbar and a small, −2×10 −2 meV / kbar 2 , quadratic contribution. Analyses of the pressure-dependent 4.2 K magnetoluminescence data yield a conduction-Band mass logarithmic pressure derivative ∂log (m c )/ ∂ P=0.58% kbar −1 .
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Pressure dependence of the Band-Gap Energy and the conduction-Band mass for an n-type InGaAs/GaAs strained single-quantum well
Physica E-low-dimensional Systems & Nanostructures, 1998Co-Authors: E D Jones, S W Tozer, T SchmiedelAbstract:Abstract We report the measurement of the pressure dependence for the Band-Gap Energy Eg and conduction-Band mass mc for an 80 A-wide n-type In0.20Ga0.80As/GaAs strained-single-quantum well at 4.2 K for pressures between 0 and 35 kbar and fields up to 30 T. The Band-Gap Energy Eg, at each pressure, was determined by extrapolating the magnetoluminescence “fan-diagram” to zero magnetic field. The pressure dependence of the Band-Gap Energy was found to be quadratic with a linear term of about 10.3 meV/kbar and a small, −2×10 −2 meV / kbar 2 , quadratic contribution. Analyses of the pressure-dependent 4.2 K magnetoluminescence data yield a conduction-Band mass logarithmic pressure derivative ∂log (m c )/ ∂ P=0.58% kbar −1 .
Harlan U. Anderson - One of the best experts on this subject based on the ideXlab platform.
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The Optical Properties and Band Gap Energy of Nanocrystalline La0.4Sr0.6TiO3 Thin Films
Journal of the American Ceramic Society, 2005Co-Authors: Toshio Suzuki, Vladimir Petrovsky, Piotr Jasinski, Harlan U. AndersonAbstract:The effects of microstructure on the optical properties of La 0.4 Sr 0.6 TiO 3 thin films were investigated. Dense films with the thickness of ∼200 nm and grain size 14-30 nm were produced on monocrystalline sapphire substrates by using a polymeric precursor spin coating technique at annealing temperatures under 800' C. X-ray data showed the formation of a single-phase cubic perovskite-type structure similar to undoped SrTiO 3 for annealing temperatures >500°C. The results of optical measurements showed that the optical spectra varied with the change of the grain size. From these data, the absorption coefficients were calculated and the Band Gap Energy determined. In agreement with the quantum confinement model, it was shown that the Band Gap Energy increased as the grain size decreased.
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Band Gap Energy in nanocrystalline ZrO2:16%Y thin films
Applied Physics Letters, 1999Co-Authors: Igor Kosacki, Vladimir Petrovsky, Harlan U. AndersonAbstract:The results of optical absorption measurements on nanocrystalline ZrO2:16%Y thin films are presented. Dense 0.7 μm thick films with 1–300 nm grain size have been obtained on sapphire substrate using a polymeric precursor spin coating technique. The relationship between the Energy Gap and microstructure of ZrO2:16%Y has been determined and discussed. The quantum confinement effect was observed at the grain size lower than 100 nm with the Band Gap Energy shift of 0.25 eV when the microstructure was changed up to 1 nm. Some limitation of the model has been observed and discussed. The Band Gap Energy of 5.62±0.05 eV has been determined as microstructure independent value.
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Band Gap Energy in nanocrystalline zro2 16 y thin films
Applied Physics Letters, 1999Co-Authors: Igor Kosacki, Vladimir Petrovsky, Harlan U. AndersonAbstract:The results of optical absorption measurements on nanocrystalline ZrO2:16%Y thin films are presented. Dense 0.7 μm thick films with 1–300 nm grain size have been obtained on sapphire substrate using a polymeric precursor spin coating technique. The relationship between the Energy Gap and microstructure of ZrO2:16%Y has been determined and discussed. The quantum confinement effect was observed at the grain size lower than 100 nm with the Band Gap Energy shift of 0.25 eV when the microstructure was changed up to 1 nm. Some limitation of the model has been observed and discussed. The Band Gap Energy of 5.62±0.05 eV has been determined as microstructure independent value.
G Landwehr - One of the best experts on this subject based on the ideXlab platform.
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e0 Band Gap Energy and lattice constant of ternary zn1 xmgxse as functions of composition
Applied Physics Letters, 1996Co-Authors: B Jobst, D Hommel, U Lunz, T Gerhard, G LandwehrAbstract:The E0 Band Gap energies and the lattice constants of zinc‐blende Zn1−xMgxSe alloys grown by molecular beam epitaxy in the composition range of 0≤x≤0.95 are determined. A nonlinear dependence on the composition is observed for both the Band‐Gap energies and the lattice con‐ stants of the ternary alloys. To our knowledge this is an initial report of a bowing in the lattice constant of a ternary II–VI alloy. Considering the bowings, the Band‐Gap Energy and the lattice constant of zinc‐blende MgSe are extrapolated to be about 4.0 eV and 5.91 A, respectively.
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E0 Band‐Gap Energy and lattice constant of ternary Zn1−xMgxSe as functions of composition
Applied Physics Letters, 1996Co-Authors: B Jobst, D Hommel, U Lunz, T Gerhard, G LandwehrAbstract:The E0 Band Gap energies and the lattice constants of zinc‐blende Zn1−xMgxSe alloys grown by molecular beam epitaxy in the composition range of 0≤x≤0.95 are determined. A nonlinear dependence on the composition is observed for both the Band‐Gap energies and the lattice con‐ stants of the ternary alloys. To our knowledge this is an initial report of a bowing in the lattice constant of a ternary II–VI alloy. Considering the bowings, the Band‐Gap Energy and the lattice constant of zinc‐blende MgSe are extrapolated to be about 4.0 eV and 5.91 A, respectively.
E D Jones - One of the best experts on this subject based on the ideXlab platform.
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pressure dependence of the Band Gap Energy and the conduction Band mass for an n type ingaas gaas strained single quantum well
Physica E-low-dimensional Systems & Nanostructures, 1998Co-Authors: E D Jones, S W Tozer, T SchmiedelAbstract:Abstract We report the measurement of the pressure dependence for the Band-Gap Energy Eg and conduction-Band mass mc for an 80 A-wide n-type In0.20Ga0.80As/GaAs strained-single-quantum well at 4.2 K for pressures between 0 and 35 kbar and fields up to 30 T. The Band-Gap Energy Eg, at each pressure, was determined by extrapolating the magnetoluminescence “fan-diagram” to zero magnetic field. The pressure dependence of the Band-Gap Energy was found to be quadratic with a linear term of about 10.3 meV/kbar and a small, −2×10 −2 meV / kbar 2 , quadratic contribution. Analyses of the pressure-dependent 4.2 K magnetoluminescence data yield a conduction-Band mass logarithmic pressure derivative ∂log (m c )/ ∂ P=0.58% kbar −1 .
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Pressure dependence of the Band-Gap Energy and the conduction-Band mass for an n-type InGaAs/GaAs strained single-quantum well
Physica E-low-dimensional Systems & Nanostructures, 1998Co-Authors: E D Jones, S W Tozer, T SchmiedelAbstract:Abstract We report the measurement of the pressure dependence for the Band-Gap Energy Eg and conduction-Band mass mc for an 80 A-wide n-type In0.20Ga0.80As/GaAs strained-single-quantum well at 4.2 K for pressures between 0 and 35 kbar and fields up to 30 T. The Band-Gap Energy Eg, at each pressure, was determined by extrapolating the magnetoluminescence “fan-diagram” to zero magnetic field. The pressure dependence of the Band-Gap Energy was found to be quadratic with a linear term of about 10.3 meV/kbar and a small, −2×10 −2 meV / kbar 2 , quadratic contribution. Analyses of the pressure-dependent 4.2 K magnetoluminescence data yield a conduction-Band mass logarithmic pressure derivative ∂log (m c )/ ∂ P=0.58% kbar −1 .
Nizami Gasanly - One of the best experts on this subject based on the ideXlab platform.
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Investigation of Band Gap Energy versus temperature for SnS2 thin films grown by RF-magnetron sputtering
Physica B: Condensed Matter, 2020Co-Authors: Mehmet Isik, Hasan Hüseyin Güllü, M. Terlemezoglu, Ö. Bayraklı Sürücü, Mehmet Parlak, Nizami GasanlyAbstract:Abstract SnS2 thin films grown by magnetron sputtering technique were characterized by structurally and optically in the present work. Crystalline parameters, atomic compositions, and surface characteristics of SnS2 thin films were presented according to results of applied structural techniques. Optical studies of SnS2 thin films were accomplished by Raman spectroscopy and transmission methods. Raman spectrum exhibited two modes around 198 and 320 cm−1. Transmittance data obtained for various temperatures between 10 and 300 K were analyzed to reveal various optical characteristics like Band Gap Energy, variation rate of Gap Energy with temperature, average phonon Energy, Gap Energy at absolute zero. Band Gap Energy of SnS2 thin films were reported as 2.18 and 2.22 eV at 300 and 10 K, respectively. The temperature-Band Gap Energy dependency was analyzed taking into account the Varshni and O'Donnell-Chen models.
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Composition-tuned Band Gap Energy and refractive index in GaSxSe1−x layered mixed crystals
Materials Chemistry and Physics, 2017Co-Authors: Mehmet Isik, Nizami GasanlyAbstract:Abstract Transmission and reflection measurements on GaSxSe1−x mixed crystals (0 ≤ x ≤ 1) were carried out in the 400–1000 nm spectral range. Band Gap energies of the studied crystals were obtained using the derivative spectra of transmittance and reflectance. The compositional dependence of Band Gap Energy revealed that as sulfur (selenium) composition is increased (decreased) in the mixed crystals, Band Gap Energy increases quadratically from 1.99 eV (GaSe) to 2.55 eV (GaS). Spectral dependencies of refractive indices of the mixed crystals were plotted using the reflectance spectra. It was observed that refractive index decreases nearly in a linear behavior with increasing Band Gap Energy for GaSxSe1−x mixed crystals. Moreover, the composition ratio of the mixed crystals was obtained from the Energy dispersive spectroscopy measurements. The atomic compositions of the studied crystals are well-matched with composition x increasing from 0 to 1 by intervals of 0.25.
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Temperature-tuned Band Gap Energy and oscillator parameters of GaS0.5Se0.5 single crystals
Optik, 2016Co-Authors: Mehmet Isik, Evrin Tugay, Nizami GasanlyAbstract:Abstract Temperature-dependent transmission and room temperature reflection measurements were carried out on GaS 0.5 Se 0.5 single crystal in the wavelength range of 380–1000 nm to investigate its optical parameters. The analysis of the temperature-dependent absorption data showed that direct and indirect Band Gap energies increase from 2.36 to 2.50 eV and 2.27 to 2.40 eV, respectively, as temperature is decreased from 300 to 10 K. The rates of change of the direct and indirect Band Gap energies with temperature was found around −7.4 × 10 −4 eV/K from the analysis of experimental data under the light of theoretical relation giving the Band Gap Energy as a function of temperature. The absolute zero value of the Band Gap energies were also found from the same analysis as 2.50 eV (for direct) and 2.40 eV (for indirect). Wemple-DiDomenico single effective oscillator model, Sellmeier oscillator model and Spitzer-Fan model were used for the room temperature reflection data to find optical parameters of the crystal.
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TEMPERATURE-TUNED Band Gap Energy AND OSCILLATOR PARAMETERS OF TlInSeS LAYERED SINGLE CRYSTALS
International Journal of Modern Physics B, 2008Co-Authors: Nizami Gasanly, I. GulerAbstract:The parameters of monoclinic unit cell of TlInSeS layered crystals were determined from X-ray powder diffraction study. The optical properties of TlInSeS have been investigated by means of transmission and reflection measurements in the wavelength range of 500–1100 nm. The optical indirect transitions with Band Gap Energy of 2.05 eV and direct transitions with Band Gap Energy of 2.21 eV were found by means of the analysis of the absorption data at room temperature. Transmission measurements carried out in the temperature range of 10–300 K revealed that the rate of change of the indirect Band Gap with temperature is γ = -4.7 × 10-4 eV/K. The dispersion of the refractive index is discussed in terms of the single oscillator model. The refractive index dispersion parameters: oscillator wavelength and strength were found to be 2.78 × 10-7 m and 1.21 × 1014m-2, respectively.
