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T. W. Kim - One of the best experts on this subject based on the ideXlab platform.
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Phase stability and single phase compositional ranges in the In1-xGaxP epitaxial layers grown on GaAs (100) substrates
Solid State Communications, 1999Co-Authors: T. W. Kim, Hyung-sik ParkAbstract:Abstract Photoluminescence (PL) and double-crystal X-ray rocking curve (DCRC) measurements were performed to investigate the phase stability and the single phase compositional ranges in In 1− x Ga x P epitaxial layers grown on GaAs (100) substrates by liquid phase epitaxy (LPE) at 735°C. The results of the PL and DCRC measurements show that the PL peak energy at 17 K vary linearly from 1.967 to 1.997 eV and the lattice-mismatch at 300 K from +0.38 to −0.17%, according to the Ga mole fraction in the growth melts. These results indicate that the composition pulling phenomena do not occur in LPE growth of the In 1− x Ga x P epitaxial layers on the GaAs (100) substrates. The phase stability and the single phase compositional ranges in In 1− x Ga x P/GaAs Strained Heterostructures are also discussed.
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The dependence of the strain effects on the ZnTe layer thicknesses in ZnTe/GaAs Heterostructures
Solid State Communications, 1998Co-Authors: M. S. Han, T. W. Kang, T. W. KimAbstract:Photoluminescence (PL) and spectroscopic ellipsometry measurements on ZnTe/GaAs Strained Heterostructures grown by molecular beam epitaxy were carried out to investigate the strain effect depending on the ZnTe epitaxial layer thickness. PL spectra show that the PL peaks corresponding to the excitons bound to neutral acceptors shift toward the higher-energy side with increasing the ZnTe film thickness. As the strain increases, the value of the critical-point energy shift obtained from the spectroscopic ellipsomerty increases. The strains in the ZnTe layers grown on GaAs substrates are expected to decrease with increasing the ZnTe layer thickness. These results indicate that the strains in the ZnTe layers grown on GaAs substrates are strongly dependent on the ZnTe layer thickness.
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Hydrogenation and annealing behaviors of deep levels in Strained CdTe(111)/GaAs(100) Heterostructures
Journal of Applied Physics, 1998Co-Authors: Moon-deock Kim, T. W. Kang, T. W. KimAbstract:Photo-induced-current transient spectroscopy measurements on CdTe/GaAs Strained Heterostructures grown by molecular beam epitaxy were carried out to investigate the hydrogenation and the annealing behaviors of the deep levels due to the crystal defects. The six hole-traps of the as-grown CdTe epilayer were observed. As the growth temperature and the rapid thermal annealing (RTA) temperature increased, the intensities of the H5 and the H6 peaks due to the crystal defects decreased, and that of the peak related to the shallow impurities increased. After annealing, the H5 and the H6 deep levels did not disappear in CdTe/GaAs Heterostructures. These results indicate that the H5 and the H6 deep levels are related to the crystal defects due to the lattice mismatch. While the H6 signal was remarkably affected by the growth temperature of the CdTe epilayer, it was independent of the thickness of the CdTe. These results indicate that the crystallinity of a CdTe epilayer grown on GaAs(100) is improved by RTA, and t...
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Structural and optical properties of undoped and doped ZnSe/GaAs Strained Heterostructures
Thin Solid Films, 1997Co-Authors: T. W. Kim, Myung-hwan Jung, D.u Lee, Sungsam Lee, Han-gyun Jung, Moon-deock Kim, Jun-youn Kim, Hong-sick Park, Junehawk LeeAbstract:Abstract Double-crystal X-ray rocking curve (DCRC), Auger electron spectroscopy (AES), transmission electron microscopy (TEM), photoluminescence (PL), and Raman scattering measurements on undoped and doped ZnSe epitaxial films grown on GaAs (100) substrates by molecular beam epitaxy were performed to investigate the structural and optical properties of the ZnSe films. From the DCRC analyses, the grown layer was found to be a ZnSe epitaxial film with high quality. The results of TEM measurements showed that the misfit dislocations of the nitrogen-doped ZnSe thin films was reduced in comparison with those of the undoped ZnSe films. The PL spectra of the nitrogen-doped ZnSe epilayer was dominated by donor–acceptor pair recombination and by a sequence of its longitudinal optical phonon replicas. Raman spectroscopy measurements showed that there was a lattice mismatch between the ZnSe epitaxial layer and the GaAs substrate and that a plasma–phonon coupling mode existed together with its characteristic longitudinal optical phonons. These results indicate that the ZnSe epitaxial films grown on GaAs hold promise for applications as buffer layers for the growth of Zn 1− x Mg x S y Se 1− y . © 1997 Elsevier Science S.A.
Hyung-sik Park - One of the best experts on this subject based on the ideXlab platform.
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Correlation between the ordered structure and the valence-band splitting in highly Strained CdxZn1-xTe epilayers
Applied Physics Letters, 2003Co-Authors: Taewhan Kim, Kae-dal Kwack, Jea Gun Park, H. S. Lee, Juno Lee, M. S. Jang, Hyung-sik ParkAbstract:Selected-area electron diffraction pattern (SADP) results showed two sets of {1/2 1/2 1/2} superstructure reflections with symmetrical intensities along the [110] axis, and the corresponding high-resolution transmission electron microscopy images indicated a doublet periodicity in the contrast of the {111} lattice planes. Photoluminescence spectra from highly Strained CdxZn1−xTe/GaAs Heterostructures showed that the valence-band splitting into the heavy hole and the light hole bands occurred as the Cd mole fraction was increased. The valence-band splitting is strongly correlated to the CuPtB-type ordered structure in highly Strained Heterostructures.
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Phase stability and single phase compositional ranges in the In1-xGaxP epitaxial layers grown on GaAs (100) substrates
Solid State Communications, 1999Co-Authors: T. W. Kim, Hyung-sik ParkAbstract:Abstract Photoluminescence (PL) and double-crystal X-ray rocking curve (DCRC) measurements were performed to investigate the phase stability and the single phase compositional ranges in In 1− x Ga x P epitaxial layers grown on GaAs (100) substrates by liquid phase epitaxy (LPE) at 735°C. The results of the PL and DCRC measurements show that the PL peak energy at 17 K vary linearly from 1.967 to 1.997 eV and the lattice-mismatch at 300 K from +0.38 to −0.17%, according to the Ga mole fraction in the growth melts. These results indicate that the composition pulling phenomena do not occur in LPE growth of the In 1− x Ga x P epitaxial layers on the GaAs (100) substrates. The phase stability and the single phase compositional ranges in In 1− x Ga x P/GaAs Strained Heterostructures are also discussed.
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Elastic strain effects dependence on the energy band gaps and the lattice parameters in CdTe epitaxial layers on GaAs (100) substrates grown by hot wall epitaxy
Solid State Communications, 1992Co-Authors: Jae Hoon Lee, S. B. Kim, B. J. Koo, I.h. Chung, M. Jung, Hyung-sik Park, Taewhan KimAbstract:Abstract Electrolyte electroreflectance spectroscopy and X-ray diffraction measurements on CdTe/GaAs Strained Heterostructures grown by hot wall epitaxy were carried out to investigate the effect of the elastic strain dependence on the energy band gaps and the lattice parameters. Biaxial compressive strains existed in CdTe layers thinner than 3 μm. This critical thickness was the smallest value for any CdTe/GaAs Heterostructures previously grown by hot wall epitaxy. The results from electrolyte electroreflectance spectroscopy and X-ray diffraction were in good qualitative agreement with each other.
T. W. Kang - One of the best experts on this subject based on the ideXlab platform.
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Hydrogenation and annealing behaviors of deep levels in Strained CdTe(111)/GaAs(100) Heterostructures
Journal of Applied Physics, 1998Co-Authors: Moon-deock Kim, T. W. Kang, T. W. KimAbstract:Photo-induced-current transient spectroscopy measurements on CdTe/GaAs Strained Heterostructures grown by molecular beam epitaxy were carried out to investigate the hydrogenation and the annealing behaviors of the deep levels due to the crystal defects. The six hole-traps of the as-grown CdTe epilayer were observed. As the growth temperature and the rapid thermal annealing (RTA) temperature increased, the intensities of the H5 and the H6 peaks due to the crystal defects decreased, and that of the peak related to the shallow impurities increased. After annealing, the H5 and the H6 deep levels did not disappear in CdTe/GaAs Heterostructures. These results indicate that the H5 and the H6 deep levels are related to the crystal defects due to the lattice mismatch. While the H6 signal was remarkably affected by the growth temperature of the CdTe epilayer, it was independent of the thickness of the CdTe. These results indicate that the crystallinity of a CdTe epilayer grown on GaAs(100) is improved by RTA, and t...
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The dependence of the strain effects on the ZnTe layer thicknesses in ZnTe/GaAs Heterostructures
Solid State Communications, 1998Co-Authors: M. S. Han, T. W. Kang, T. W. KimAbstract:Photoluminescence (PL) and spectroscopic ellipsometry measurements on ZnTe/GaAs Strained Heterostructures grown by molecular beam epitaxy were carried out to investigate the strain effect depending on the ZnTe epitaxial layer thickness. PL spectra show that the PL peaks corresponding to the excitons bound to neutral acceptors shift toward the higher-energy side with increasing the ZnTe film thickness. As the strain increases, the value of the critical-point energy shift obtained from the spectroscopic ellipsomerty increases. The strains in the ZnTe layers grown on GaAs substrates are expected to decrease with increasing the ZnTe layer thickness. These results indicate that the strains in the ZnTe layers grown on GaAs substrates are strongly dependent on the ZnTe layer thickness.
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Strain effects in CdTe (111) epitaxial layers grown on GaAs (100) substrates by molecular beam epitaxy
Journal of Electronic Materials, 1997Co-Authors: M. S. Han, T. W. Kang, J. H. Leem, B. K. Song, Y. B. Hou, W. H. Baek, M. H. Lee, J. H. Bahng, K. J. Kim, J. M. KimAbstract:Spectroscopic ellipsometry and photoreflectance measurements on CdTe/GaAs Strained Heterostructures grown by moleculclr beam epitaxy were carried out to investigate the effect of the strain and the dependence of the lattice parameter on the CdTe epitaxial layer thicknesses. Compressive strains exist in CdTe layers thinner than 2 µm. As the strain increases, the value of the critical-point energy shift increases linearly. These results indicate that the strains in the CdTe layers grown on GaAs substrates are strongly dependent on the CdTe layer thickness.
M. S. Han - One of the best experts on this subject based on the ideXlab platform.
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The dependence of the strain effects on the ZnTe layer thicknesses in ZnTe/GaAs Heterostructures
Solid State Communications, 1998Co-Authors: M. S. Han, T. W. Kang, T. W. KimAbstract:Photoluminescence (PL) and spectroscopic ellipsometry measurements on ZnTe/GaAs Strained Heterostructures grown by molecular beam epitaxy were carried out to investigate the strain effect depending on the ZnTe epitaxial layer thickness. PL spectra show that the PL peaks corresponding to the excitons bound to neutral acceptors shift toward the higher-energy side with increasing the ZnTe film thickness. As the strain increases, the value of the critical-point energy shift obtained from the spectroscopic ellipsomerty increases. The strains in the ZnTe layers grown on GaAs substrates are expected to decrease with increasing the ZnTe layer thickness. These results indicate that the strains in the ZnTe layers grown on GaAs substrates are strongly dependent on the ZnTe layer thickness.
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Strain effects in CdTe (111) epitaxial layers grown on GaAs (100) substrates by molecular beam epitaxy
Journal of Electronic Materials, 1997Co-Authors: M. S. Han, T. W. Kang, J. H. Leem, B. K. Song, Y. B. Hou, W. H. Baek, M. H. Lee, J. H. Bahng, K. J. Kim, J. M. KimAbstract:Spectroscopic ellipsometry and photoreflectance measurements on CdTe/GaAs Strained Heterostructures grown by moleculclr beam epitaxy were carried out to investigate the effect of the strain and the dependence of the lattice parameter on the CdTe epitaxial layer thicknesses. Compressive strains exist in CdTe layers thinner than 2 µm. As the strain increases, the value of the critical-point energy shift increases linearly. These results indicate that the strains in the CdTe layers grown on GaAs substrates are strongly dependent on the CdTe layer thickness.
Taewhan Kim - One of the best experts on this subject based on the ideXlab platform.
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Correlation between the ordered structure and the valence-band splitting in highly Strained CdxZn1-xTe epilayers
Applied Physics Letters, 2003Co-Authors: Taewhan Kim, Kae-dal Kwack, Jea Gun Park, H. S. Lee, Juno Lee, M. S. Jang, Hyung-sik ParkAbstract:Selected-area electron diffraction pattern (SADP) results showed two sets of {1/2 1/2 1/2} superstructure reflections with symmetrical intensities along the [110] axis, and the corresponding high-resolution transmission electron microscopy images indicated a doublet periodicity in the contrast of the {111} lattice planes. Photoluminescence spectra from highly Strained CdxZn1−xTe/GaAs Heterostructures showed that the valence-band splitting into the heavy hole and the light hole bands occurred as the Cd mole fraction was increased. The valence-band splitting is strongly correlated to the CuPtB-type ordered structure in highly Strained Heterostructures.
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Elastic strain effects dependence on the energy band gaps and the lattice parameters in CdTe epitaxial layers on GaAs (100) substrates grown by hot wall epitaxy
Solid State Communications, 1992Co-Authors: Jae Hoon Lee, S. B. Kim, B. J. Koo, I.h. Chung, M. Jung, Hyung-sik Park, Taewhan KimAbstract:Abstract Electrolyte electroreflectance spectroscopy and X-ray diffraction measurements on CdTe/GaAs Strained Heterostructures grown by hot wall epitaxy were carried out to investigate the effect of the elastic strain dependence on the energy band gaps and the lattice parameters. Biaxial compressive strains existed in CdTe layers thinner than 3 μm. This critical thickness was the smallest value for any CdTe/GaAs Heterostructures previously grown by hot wall epitaxy. The results from electrolyte electroreflectance spectroscopy and X-ray diffraction were in good qualitative agreement with each other.