The Experts below are selected from a list of 16437 Experts worldwide ranked by ideXlab platform
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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The Hall Mobility and its relationship with persistent photoconductivity of undoped GaN
Journal of Electronic Materials, 2000Co-Authors: Wei Wang, Soo Jin ChuaAbstract:Temperature-variable Hall effect measurements have been used to investigate the electrical properties of undoped GaN, which have the electron densities on the order of mid-1016 cm−3 and a Hall Mobility varying from 500 cm2/sV. We found that very strong ionized impurity scattering limits the Hall Mobility of GaN. Illumination even at 77 K has very little effect on the electron density but can lead to a noticeable persistent increase of the Hall Mobility. The induced persistent photoconductivity (PPC) effect is therefore related to the Hall Mobility through intrinsic electrically active defects. The properties of those defects were further investigated by monitoring a transient change of resistivity after removal of illumination at different temperatures. It reveals that the recapturing process of excited electrons into illumination-neutralized defects is the mechanism responsible for the PPC effect of undoped GaN.
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The Hall Mobility and its relationship to the persistent photoconductivity of undoped GaN
Solid State Communications, 1999Co-Authors: Soo Jin Chua, Wei WangAbstract:Abstract Temperature-variable Hall effect measurements have been used to investigate the electrical properties of undoped GaN, which has electron densities in the order of mid-10 16 cm −3 and the Hall Mobility varying from 2 /sV to >500 cm 2 /sV. We found that very strong ionized impurity scattering limits the Hall Mobility of GaN. Illumination even at 77 K has very little effect on the electron density but can lead to a noticeable persistent increase of the Hall Mobility. The induced persistent photoconductivity (PPC) effect is, therefore, related to the Hall Mobility through intrinsic electrically active defects. The properties of those defects were further investigated by monitoring the transient change of resistivity after removal of illumination at different temperatures. We have found that the recapturing process of excited electrons into illumination-neutralized defects is the mechanism responsible for the PPC effect of undoped GaN.
Peter Kordos - One of the best experts on this subject based on the ideXlab platform.
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Hall Mobility analysis in low‐temperature‐grown molecular‐beam epitaxial GaAs
Applied Physics Letters, 1996Co-Authors: J. Betko, M. Morvic, Jozef Novak, A. Förster, Peter KordosAbstract:Temperature dependent conductivity and Hall effect measurements were carried out on molecular‐beam epitaxial GaAs layers grown at 200–420 °C and separated from the substrate. An analysis of experimental data with and without considering the hopping Hall Mobility was made. An extremely low room temperature Hall Mobility of 0.14 cm2 V−1 s−1 was measured in the 250 °C layer, which could be interpreted as the hopping Hall Mobility. The room temperature band Hall Mobility (μHb) increases from 500 to 6000 cm2 V−1 s−1 and the power (n) of the temperature dependence of μHb (∼T−n) increases from 0.5 to 1.2 with increasing growth temperature from 300 to 420 °C.
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Hall Mobility analysis in low temperature grown molecular beam epitaxial gaas
Applied Physics Letters, 1996Co-Authors: J. Betko, M. Morvic, Jozef Novak, A. Förster, Peter KordosAbstract:Temperature dependent conductivity and Hall effect measurements were carried out on molecular‐beam epitaxial GaAs layers grown at 200–420 °C and separated from the substrate. An analysis of experimental data with and without considering the hopping Hall Mobility was made. An extremely low room temperature Hall Mobility of 0.14 cm2 V−1 s−1 was measured in the 250 °C layer, which could be interpreted as the hopping Hall Mobility. The room temperature band Hall Mobility (μHb) increases from 500 to 6000 cm2 V−1 s−1 and the power (n) of the temperature dependence of μHb (∼T−n) increases from 0.5 to 1.2 with increasing growth temperature from 300 to 420 °C.
W. Siegel - One of the best experts on this subject based on the ideXlab platform.
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Parameters of mesoscopic non-uniformities and their influence on the Hall Mobility in undoped high-resistivity LEC GaAs
Semiconductor Science and Technology, 1999Co-Authors: W. Siegel, S. Schulte, U. Kretzer, G. KühnelAbstract:The Hall Mobility in undoped high-resistivity GaAs grown by the liquid encapsulation Czochralski technique is strongly reduced due to mesoscopic electrical non-uniformities related to the cellular structure of dislocations. According to model calculations using effective medium theory and approximating the non-uniformities by a mixture of two different phases (cell walls and cell interiors) the most essential inhomogeneity parameters are the ratio of the carrier concentrations and the ratio of the volumes of both phases. Comparing the calculated dependences of the Hall Mobility on the carrier concentration and on the temperature with experimental results the different influences of both parameters could be separated.
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Anomalous temperature dependence of the Hall Mobility in undoped bulk GaAs
Journal of Applied Physics, 1997Co-Authors: W. Siegel, G. Kühnel, S. Schulte, C. Reichel, J. MoneckeAbstract:Undoped liquid encapsulated Czochralski grown GaAs crystals with a transition from semi-insulating to medium-resistivity behavior show unusual low values of the Hall Mobility at 300 K in this transition region. Moreover, in samples of this region an anomalous temperature dependence of μH characterized by an increase of μH with increasing temperature for T
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Enhancement of the Hall Mobility in undoped GaAs with low carrier concentration by light excitation
Applied Physics Letters, 1997Co-Authors: V. Kažukauskas, G. Kühnel, W. SiegelAbstract:We report the investigation of the steady-state Hall Mobility behavior upon extrinsic light excitation in n-type liquid-encapsulated Czochralski GaAs crystals. The carrier concentration of the samples measured in the dark ranged from 108 to 3×1011 cm−3. The Hall Mobility demonstrated a pronounced minimum in the concentration region 109–1011 cm−3. In samples of this region a significant increase of the Hall Mobility from ⩾1460 to 6300–7800 cm2 V s could be induced by light, in some cases without an increase of the measured carrier concentration. Such behavior was explained by reduction of the mesoscopic nonuniformities related to the cellular structure of dislocations by the carriers generated from defect levels in the band gap.
Tonio Buonassisi - One of the best experts on this subject based on the ideXlab platform.
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Hall Mobility of cuprous oxide thin films deposited by reactive direct current magnetron sputtering
Applied Physics Letters, 2011Co-Authors: Yun Seog Lee, Mark T Winkler, Sin Cheng Siah, Riley E Brandt, Tonio BuonassisiAbstract:Cuprous oxide (Cu2O) is a promising earth-abundant semiconductor for photovoltaic applications. We report Hall mobilities of polycrystalline Cu2O thin films deposited by reactive dc magnetron sputtering. High substrate growth temperature enhances film grain structure and Hall Mobility. Temperature-dependent Hall mobilities measured on these films are comparable to monocrystalline Cu2O at temperatures above 250 K, reaching 62 cm2/V s at room temperature. At lower temperatures, the Hall Mobility appears limited by carrier scattering from ionized centers. These observations indicate that sputtered Cu2O films at high substrate growth temperature may be suitable for thin-film photovoltaic applications.
Soo Jin Chua - One of the best experts on this subject based on the ideXlab platform.
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The Hall Mobility and its relationship with persistent photoconductivity of undoped GaN
Journal of Electronic Materials, 2000Co-Authors: Wei Wang, Soo Jin ChuaAbstract:Temperature-variable Hall effect measurements have been used to investigate the electrical properties of undoped GaN, which have the electron densities on the order of mid-1016 cm−3 and a Hall Mobility varying from 500 cm2/sV. We found that very strong ionized impurity scattering limits the Hall Mobility of GaN. Illumination even at 77 K has very little effect on the electron density but can lead to a noticeable persistent increase of the Hall Mobility. The induced persistent photoconductivity (PPC) effect is therefore related to the Hall Mobility through intrinsic electrically active defects. The properties of those defects were further investigated by monitoring a transient change of resistivity after removal of illumination at different temperatures. It reveals that the recapturing process of excited electrons into illumination-neutralized defects is the mechanism responsible for the PPC effect of undoped GaN.
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The Hall Mobility and its relationship to the persistent photoconductivity of undoped GaN
Solid State Communications, 1999Co-Authors: Soo Jin Chua, Wei WangAbstract:Abstract Temperature-variable Hall effect measurements have been used to investigate the electrical properties of undoped GaN, which has electron densities in the order of mid-10 16 cm −3 and the Hall Mobility varying from 2 /sV to >500 cm 2 /sV. We found that very strong ionized impurity scattering limits the Hall Mobility of GaN. Illumination even at 77 K has very little effect on the electron density but can lead to a noticeable persistent increase of the Hall Mobility. The induced persistent photoconductivity (PPC) effect is, therefore, related to the Hall Mobility through intrinsic electrically active defects. The properties of those defects were further investigated by monitoring the transient change of resistivity after removal of illumination at different temperatures. We have found that the recapturing process of excited electrons into illumination-neutralized defects is the mechanism responsible for the PPC effect of undoped GaN.
