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Chunming Wang - One of the best experts on this subject based on the ideXlab platform.

  • cuau zno graphene nanocomposite a novel graphene based bimetallic Alloy Semiconductor catalyst with its enhanced photocatalytic degradation performance
    Journal of Alloys and Compounds, 2015
    Co-Authors: Hong Xie, Kaiyue Duan, Muyin Xue, Chunming Wang
    Abstract:

    Abstract The bimetallic Alloy CuAu nanoparticles (NPs) can produce more photogenerated electrons when compared with single metal Au NPs. Moreover, graphene (Gr) sheets can help the charge separation and slow down the recombination of the electron hole pairs of ZnO. Hence, a novel graphene-based bimetallic Alloy-Semiconductor catalyst: CuAu–ZnO–Gr nanocomposite is synthesized. Due to the synergistic effect among CuAu NPs, ZnO nanopyramids, and Gr sheets, CuAu–ZnO–Gr behaves an enhanced photocatalytic activity for the photocatalytic degradation of synthetic colorants methyl orange (MO), methylene blue (MB), indigotin (IN), sunset yellow (SY), and tartrazine (TT) under the simulated sunlight irradiation. Furthermore, the apparent rate constants (kapp) of MO, MB, IN, SY, and TT degradation are estimated respectively. In addition, the as-prepared CuAu–ZnO–Gr nanocomposite is characterized by X-ray diffraction, UV–vis spectrum, transmission electron microscopy, energy dispersive X-ray analysis (EDX), and EDX mapping. As a result of the facile synthesis route and the enhanced photocatalytic activity, this new material CuAu–ZnO–Gr can be a promising photocatalyst for the degradation of dyes.

  • CuAu–ZnO–graphene nanocomposite: A novel graphene-based bimetallic Alloy-Semiconductor catalyst with its enhanced photocatalytic degradation performance
    Journal of Alloys and Compounds, 2015
    Co-Authors: Hong Xie, Kaiyue Duan, Muyin Xue, Chunming Wang
    Abstract:

    Abstract The bimetallic Alloy CuAu nanoparticles (NPs) can produce more photogenerated electrons when compared with single metal Au NPs. Moreover, graphene (Gr) sheets can help the charge separation and slow down the recombination of the electron hole pairs of ZnO. Hence, a novel graphene-based bimetallic Alloy-Semiconductor catalyst: CuAu–ZnO–Gr nanocomposite is synthesized. Due to the synergistic effect among CuAu NPs, ZnO nanopyramids, and Gr sheets, CuAu–ZnO–Gr behaves an enhanced photocatalytic activity for the photocatalytic degradation of synthetic colorants methyl orange (MO), methylene blue (MB), indigotin (IN), sunset yellow (SY), and tartrazine (TT) under the simulated sunlight irradiation. Furthermore, the apparent rate constants (kapp) of MO, MB, IN, SY, and TT degradation are estimated respectively. In addition, the as-prepared CuAu–ZnO–Gr nanocomposite is characterized by X-ray diffraction, UV–vis spectrum, transmission electron microscopy, energy dispersive X-ray analysis (EDX), and EDX mapping. As a result of the facile synthesis route and the enhanced photocatalytic activity, this new material CuAu–ZnO–Gr can be a promising photocatalyst for the degradation of dyes.

Y Momose - One of the best experts on this subject based on the ideXlab platform.

  • Growth of In_xGa_1−xSb Alloy Semiconductor at the International Space Station (ISS) and comparison with terrestrial experiments
    npj Microgravity, 2015
    Co-Authors: Y Inatomi, K Sakata, M Arivanandhan, G Rajesh, V Nirmal Kumar, T Koyama, Y Momose, T Ozawa, Y Okano, Y Hayakawa
    Abstract:

    New research shows that minimizing the effects of gravity can improve the fabrication of high-tech Semiconductors. Yuko Inatomi from the Japan Aerospace Exploration Agency and co-workers investigated the growth of indium gallium antimonide (InGaSb) Alloys on the International Space Station (ISS) and under standard terrestrial conditions. The team placed ‘sandwich’ samples, where a thin InSb layer sits between thicker chunks of GaSb, into a high-temperature furnace and characterized the Alloy crystals formed in the mixing zone. The researchers found significant differences in crystal qualities and growth rates. Whereas samples grown on Earth had mostly curved growth interfaces, those formed on the ISS were nearly flat-a change that produced smoother distributions of atoms with a higher growth rate than typical conditions. The authors attribute the improved kinetics in microgravity to a reduction in convection forces at growth interfaces. Background: In_ x Ga_1− x Sb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of Alloy Semiconductors can be examined better under microgravity (μG) conditions where convection is suppressed. Aims: To investigate the dissolution and growth process of In_ x Ga_1− x Sb Alloy Semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and μG conditions. Methods: In_ x Ga_1− x Sb crystals were grown at the International Space Station (ISS) under μG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. Results: The shape of the growth interface was nearly flat under μG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the μG crystals was better than that of the 1G samples, as the etch pit density was low in the μG sample. The growth rate was higher under μG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under μG. Conclusions: Kinetics played a dominant role under 1G. The suppressed convection under μG affected the dissolution and growth process of the In_ x Ga_1− x Sb Alloy Semiconductor.

  • Growth of In x Ga1-x Sb Alloy Semiconductor at the International Space Station (ISS) and comparison with terrestrial experiments.
    NPJ microgravity, 2015
    Co-Authors: Yuko Inatomi, Mukannan Arivanandhan, Govindasamy Rajesh, Tetsuo Ozawa, Yasunori Okano, K Sakata, T Koyama, Y Momose, V. Nirmal Kumar, Yasuhiro Hayakawa
    Abstract:

    InxGa1−xSb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of Alloy Semiconductors can be examined better under microgravity (μG) conditions where convection is suppressed. To investigate the dissolution and growth process of InxGa1−xSb Alloy Semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and μG conditions. InxGa1−xSb crystals were grown at the International Space Station (ISS) under μG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. The shape of the growth interface was nearly flat under μG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the μG crystals was better than that of the 1G samples, as the etch pit density was low in the μG sample. The growth rate was higher under μG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under μG. Kinetics played a dominant role under 1G. The suppressed convection under μG affected the dissolution and growth process of the InxGa1−xSb Alloy Semiconductor. New research shows that minimizing the effects of gravity can improve the fabrication of high-tech Semiconductors. Yuko Inatomi from the Japan Aerospace Exploration Agency and co-workers investigated the growth of indium gallium antimonide (InGaSb) Alloys on the International Space Station (ISS) and under standard terrestrial conditions. The team placed ‘sandwich’ samples, where a thin InSb layer sits between thicker chunks of GaSb, into a high-temperature furnace and characterized the Alloy crystals formed in the mixing zone. The researchers found significant differences in crystal qualities and growth rates. Whereas samples grown on Earth had mostly curved growth interfaces, those formed on the ISS were nearly flat-a change that produced smoother distributions of atoms with a higher growth rate than typical conditions. The authors attribute the improved kinetics in microgravity to a reduction in convection forces at growth interfaces.

  • Analysis of dissolution and growth process of SiGe Alloy Semiconductor based on penetrated X-ray intensities
    Journal of Alloys and Compounds, 2014
    Co-Authors: Muthusamy Omprakash, Mukannan Arivanandhan, T Koyama, Y Momose, R. Arun Kumar, Hisashi Morii, Toru Aoki, Hiroya Ikeda, Hirokazu Tatsuoka, Yasunori Okano
    Abstract:

    Abstract Si dissolution into Ge melt, solute transport in the Si–Ge solution and crystal growth of SiGe Alloys were in situ observed by X-ray penetration method. The rectangular shaped sandwich sample of Si (seed)/Ge/Si (feed) was used for the experiment. X-ray intensities penetrated through the sample, which was heated up to the growth temperature of 1200 °C, were recorded by rectangular shaped CdTe line sensor as a function of time and temperature. The experimental results demonstrated that the dissolution of Si seed was larger compared to Si feed crystal although Si feed temperature was relatively higher than that of seed. Crystal growth of SiGe was observed at the feed interface as the growth interface was observed clearly by an abrupt change of penetrated X-ray intensity near the growth interface. Since the crystal grew with Si rich composition (at high temperature 1200 °C), solution becomes Ge richer which causes penetrated X-ray intensity variation at the growth interface. The growth mechanism for the observed SiGe growth process was discussed based on the penetrated X-ray intensity profile and a growth model. The composition of the grown sample was measured by FE-EPMA analysis.

T Koyama - One of the best experts on this subject based on the ideXlab platform.

  • Growth of In_xGa_1−xSb Alloy Semiconductor at the International Space Station (ISS) and comparison with terrestrial experiments
    npj Microgravity, 2015
    Co-Authors: Y Inatomi, K Sakata, M Arivanandhan, G Rajesh, V Nirmal Kumar, T Koyama, Y Momose, T Ozawa, Y Okano, Y Hayakawa
    Abstract:

    New research shows that minimizing the effects of gravity can improve the fabrication of high-tech Semiconductors. Yuko Inatomi from the Japan Aerospace Exploration Agency and co-workers investigated the growth of indium gallium antimonide (InGaSb) Alloys on the International Space Station (ISS) and under standard terrestrial conditions. The team placed ‘sandwich’ samples, where a thin InSb layer sits between thicker chunks of GaSb, into a high-temperature furnace and characterized the Alloy crystals formed in the mixing zone. The researchers found significant differences in crystal qualities and growth rates. Whereas samples grown on Earth had mostly curved growth interfaces, those formed on the ISS were nearly flat-a change that produced smoother distributions of atoms with a higher growth rate than typical conditions. The authors attribute the improved kinetics in microgravity to a reduction in convection forces at growth interfaces. Background: In_ x Ga_1− x Sb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of Alloy Semiconductors can be examined better under microgravity (μG) conditions where convection is suppressed. Aims: To investigate the dissolution and growth process of In_ x Ga_1− x Sb Alloy Semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and μG conditions. Methods: In_ x Ga_1− x Sb crystals were grown at the International Space Station (ISS) under μG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. Results: The shape of the growth interface was nearly flat under μG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the μG crystals was better than that of the 1G samples, as the etch pit density was low in the μG sample. The growth rate was higher under μG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under μG. Conclusions: Kinetics played a dominant role under 1G. The suppressed convection under μG affected the dissolution and growth process of the In_ x Ga_1− x Sb Alloy Semiconductor.

  • Growth of In x Ga1-x Sb Alloy Semiconductor at the International Space Station (ISS) and comparison with terrestrial experiments.
    NPJ microgravity, 2015
    Co-Authors: Yuko Inatomi, Mukannan Arivanandhan, Govindasamy Rajesh, Tetsuo Ozawa, Yasunori Okano, K Sakata, T Koyama, Y Momose, V. Nirmal Kumar, Yasuhiro Hayakawa
    Abstract:

    InxGa1−xSb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of Alloy Semiconductors can be examined better under microgravity (μG) conditions where convection is suppressed. To investigate the dissolution and growth process of InxGa1−xSb Alloy Semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and μG conditions. InxGa1−xSb crystals were grown at the International Space Station (ISS) under μG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. The shape of the growth interface was nearly flat under μG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the μG crystals was better than that of the 1G samples, as the etch pit density was low in the μG sample. The growth rate was higher under μG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under μG. Kinetics played a dominant role under 1G. The suppressed convection under μG affected the dissolution and growth process of the InxGa1−xSb Alloy Semiconductor. New research shows that minimizing the effects of gravity can improve the fabrication of high-tech Semiconductors. Yuko Inatomi from the Japan Aerospace Exploration Agency and co-workers investigated the growth of indium gallium antimonide (InGaSb) Alloys on the International Space Station (ISS) and under standard terrestrial conditions. The team placed ‘sandwich’ samples, where a thin InSb layer sits between thicker chunks of GaSb, into a high-temperature furnace and characterized the Alloy crystals formed in the mixing zone. The researchers found significant differences in crystal qualities and growth rates. Whereas samples grown on Earth had mostly curved growth interfaces, those formed on the ISS were nearly flat-a change that produced smoother distributions of atoms with a higher growth rate than typical conditions. The authors attribute the improved kinetics in microgravity to a reduction in convection forces at growth interfaces.

  • Analysis of dissolution and growth process of SiGe Alloy Semiconductor based on penetrated X-ray intensities
    Journal of Alloys and Compounds, 2014
    Co-Authors: Muthusamy Omprakash, Mukannan Arivanandhan, T Koyama, Y Momose, R. Arun Kumar, Hisashi Morii, Toru Aoki, Hiroya Ikeda, Hirokazu Tatsuoka, Yasunori Okano
    Abstract:

    Abstract Si dissolution into Ge melt, solute transport in the Si–Ge solution and crystal growth of SiGe Alloys were in situ observed by X-ray penetration method. The rectangular shaped sandwich sample of Si (seed)/Ge/Si (feed) was used for the experiment. X-ray intensities penetrated through the sample, which was heated up to the growth temperature of 1200 °C, were recorded by rectangular shaped CdTe line sensor as a function of time and temperature. The experimental results demonstrated that the dissolution of Si seed was larger compared to Si feed crystal although Si feed temperature was relatively higher than that of seed. Crystal growth of SiGe was observed at the feed interface as the growth interface was observed clearly by an abrupt change of penetrated X-ray intensity near the growth interface. Since the crystal grew with Si rich composition (at high temperature 1200 °C), solution becomes Ge richer which causes penetrated X-ray intensity variation at the growth interface. The growth mechanism for the observed SiGe growth process was discussed based on the penetrated X-ray intensity profile and a growth model. The composition of the grown sample was measured by FE-EPMA analysis.

T. Nishizawa - One of the best experts on this subject based on the ideXlab platform.

  • Miscibility gap in II–VI Alloy Semiconductor systems
    Journal of Alloys and Compounds, 1992
    Co-Authors: Hiroshi Ohtani, K. Kojima, T. Nishizawa
    Abstract:

    Abstract A thermodynamic calculation and analysis of the nature and extent of miscibility gaps in ternary and quaternary systems of H(Zn, Cd, Hg)-VI(S, Se, Te) Alloy Semiconductors is presented. The Gibbs energy of the zincblende-type phase has been described using a sublattice model and the interaction energies in the pseudobinary systems have been estimated from the difference in lattice constants of the components. The origin of miscibility gap in the quaternary systems is discussed.

Yasunori Okano - One of the best experts on this subject based on the ideXlab platform.

  • Growth of In x Ga1-x Sb Alloy Semiconductor at the International Space Station (ISS) and comparison with terrestrial experiments.
    NPJ microgravity, 2015
    Co-Authors: Yuko Inatomi, Mukannan Arivanandhan, Govindasamy Rajesh, Tetsuo Ozawa, Yasunori Okano, K Sakata, T Koyama, Y Momose, V. Nirmal Kumar, Yasuhiro Hayakawa
    Abstract:

    InxGa1−xSb is an important material that has tunable properties in the infrared (IR) region and is suitable for IR-device applications. Since the quality of crystals relies on growth conditions, the growth process of Alloy Semiconductors can be examined better under microgravity (μG) conditions where convection is suppressed. To investigate the dissolution and growth process of InxGa1−xSb Alloy Semiconductors via a sandwiched structure of GaSb(seed)/InSb/GaSb(feed) under normal and μG conditions. InxGa1−xSb crystals were grown at the International Space Station (ISS) under μG conditions, and a similar experiment was conducted under terrestrial conditions (1G) using the vertical gradient freezing (VGF) method. The grown crystals were cut along the growth direction and its growth properties were studied. The indium composition and growth rate of grown crystals were calculated. The shape of the growth interface was nearly flat under μG, whereas under 1G, it was highly concave with the initial seed interface being nearly flat and having facets at the peripheries. The quality of the μG crystals was better than that of the 1G samples, as the etch pit density was low in the μG sample. The growth rate was higher under μG compared with 1G. Moreover, the growth started at the peripheries under 1G, whereas it started throughout the seed interface under μG. Kinetics played a dominant role under 1G. The suppressed convection under μG affected the dissolution and growth process of the InxGa1−xSb Alloy Semiconductor. New research shows that minimizing the effects of gravity can improve the fabrication of high-tech Semiconductors. Yuko Inatomi from the Japan Aerospace Exploration Agency and co-workers investigated the growth of indium gallium antimonide (InGaSb) Alloys on the International Space Station (ISS) and under standard terrestrial conditions. The team placed ‘sandwich’ samples, where a thin InSb layer sits between thicker chunks of GaSb, into a high-temperature furnace and characterized the Alloy crystals formed in the mixing zone. The researchers found significant differences in crystal qualities and growth rates. Whereas samples grown on Earth had mostly curved growth interfaces, those formed on the ISS were nearly flat-a change that produced smoother distributions of atoms with a higher growth rate than typical conditions. The authors attribute the improved kinetics in microgravity to a reduction in convection forces at growth interfaces.

  • Analysis of dissolution and growth process of SiGe Alloy Semiconductor based on penetrated X-ray intensities
    Journal of Alloys and Compounds, 2014
    Co-Authors: Muthusamy Omprakash, Mukannan Arivanandhan, T Koyama, Y Momose, R. Arun Kumar, Hisashi Morii, Toru Aoki, Hiroya Ikeda, Hirokazu Tatsuoka, Yasunori Okano
    Abstract:

    Abstract Si dissolution into Ge melt, solute transport in the Si–Ge solution and crystal growth of SiGe Alloys were in situ observed by X-ray penetration method. The rectangular shaped sandwich sample of Si (seed)/Ge/Si (feed) was used for the experiment. X-ray intensities penetrated through the sample, which was heated up to the growth temperature of 1200 °C, were recorded by rectangular shaped CdTe line sensor as a function of time and temperature. The experimental results demonstrated that the dissolution of Si seed was larger compared to Si feed crystal although Si feed temperature was relatively higher than that of seed. Crystal growth of SiGe was observed at the feed interface as the growth interface was observed clearly by an abrupt change of penetrated X-ray intensity near the growth interface. Since the crystal grew with Si rich composition (at high temperature 1200 °C), solution becomes Ge richer which causes penetrated X-ray intensity variation at the growth interface. The growth mechanism for the observed SiGe growth process was discussed based on the penetrated X-ray intensity profile and a growth model. The composition of the grown sample was measured by FE-EPMA analysis.

  • Alloy Semiconductor Crystal Growth Under Microgravity
    2010
    Co-Authors: Yasuhiro Hayakawa, Mukannan Arivanandhan, Govindasamy Rajesh, Akira Tanaka, Tetsuo Ozawa, Yasunori Okano, K. Sankaranarayanan, Yuko Inatomi
    Abstract:

    Microgravity studies on the dissolution and crystallization of InxGa1‐xSb have been done using a sandwich combination of InSb and GaSb as the starting material using the Chinese recoverable satellite. The same type of experiment was performed under 1G gravity condition for comparison. From these experiments and the numerical simulation, it is found that the shape of the solid/liquid interface and composition profile in the solution was found to be significantly affected by gravity. GaSb seed was dissolved faster than GaSb feed even though the GaSb feed temperature was higher than that of GaSb seed temperature. These results clearly indicate that solute transport due to gravity affects dissolution and growth processes of Alloy Semiconductor bulk crystals.