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Sung Hong Hahn - One of the best experts on this subject based on the ideXlab platform.

  • photodecomposition effects of graphene oxide coated on tio2 thin film prepared by Electron Beam Evaporation method
    Thin Solid Films, 2012
    Co-Authors: Nguyen Tri Khoa, Min Wook Pyun, Jaeyoung Leem, Sung Hong Hahn
    Abstract:

    Abstract Morphological, structural and photocatalytic properties of graphene oxide (GO)/TiO 2 thin-film deposited on quartz substrate were investigated. The TiO 2 film was prepared by Electron-Beam Evaporation and the GO film by spin coating method. The photocatalytic activities of the GO/TiO 2 film were evaluated by photodecomposition of methylene blue. There was synergistic effect between TiO 2 and GO which causes a rapid photo-induced charge separation and the reduction of the recombination of Electron–hole pairs under the UV–visible light irradiation. GO on TiO 2 film also promotes the properties of adsorption of the dye, photon scattering probability, and interacting surface area. As a result, it leads to the enhancement of the efficiency of the photodegradation in GO/TiO 2 film.

  • oblique angle deposition of tio2 thin films prepared by Electron Beam Evaporation
    Applied Surface Science, 2010
    Co-Authors: Min Wook Pyun, Eui Jung Kim, Daehwang Yoo, Sung Hong Hahn
    Abstract:

    Optical, structural and photocatalytic properties of TiO2 thin films obliquely deposited on quartz glass substrate using an Electron-Beam Evaporation method were investigated. The photocatalytic activity of the films was evaluated by photodecomposition of methylene blue. An increase in incident deposition angle increased the porosity and surface roughness of the TiO2 films. As a result, the photocatalytic activity was enhanced with incident deposition angle up to 60°. However, a further increase in incident deposition angle to 75° reduced the photocatalytic activity due to a lack of the crystalline phase.

  • optical and structural properties of zno tio2 zno multi layers prepared via Electron Beam Evaporation
    Vacuum, 2009
    Co-Authors: Wonseok Choi, Eui Jung Kim, Seung Gie Seong, Yong Soo Kim, Chinho Park, Sung Hong Hahn
    Abstract:

    Abstract We prepared a ZnO/TiO 2 /ZnO multi-layer on quartz glass substrate via Electron Beam Evaporation. Optical and structural properties of the ZnO/TiO 2 /ZnO multi-layer were investigated. The TiO 2 buffer layer is found to improve the crystallinity of the ZnO thin film. A green emission of the ZnO thin film deposited on the TiO 2 buffer layer was significantly enhanced due to the increased defect concentration of oxygen vacancy. Photoluminesence spectra measured at 9 K revealed that a violet luminescence at 409 nm was attributed to the draft of the donor's defect levels in the ZnO thin film.

Masao Matsuoka - One of the best experts on this subject based on the ideXlab platform.

Jianda Shao - One of the best experts on this subject based on the ideXlab platform.

  • al2o3 sio2 films prepared by Electron Beam Evaporation as uv antireflection coatings on 4h sic
    Applied Surface Science, 2008
    Co-Authors: Feng Zhang, Zhengxiu Fan, Huili Zhu, Weifeng Yang, Jianda Shao
    Abstract:

    Al2O3/SiO2 films have been deposited as UV antireflection coatings on 4H-SiC by Electron-Beam Evaporation and characterized by reflection spectrum, scanning Electron microscopy (SEM) and X-ray photoElectron spectroscopy (XPS). The reflectance of the Al2O3/SiO2 films is 0.33% and 10 times lower than that of a thermally grown SiO2 single layer at 276 nm. The films are amorphous in microstructure and characterize good adhesion to 4H-SiC substrate. XPS results indicate an abrupt interface between evaporated SiO2 and 4H-SiC substrate free of Si-suboxides. These results make the possibility for 4H-SiC based high performance UV optoElectronic devices with Al2O3/SiO2 films as antireflection coatings. (C) 2007 Elsevier B.V. All rights reserved.

  • optical and electrical properties of tiox thin films deposited by Electron Beam Evaporation
    Vacuum, 2007
    Co-Authors: Jianke Yao, Jianda Shao, Zhengxiu Fan
    Abstract:

    Abstract The TiO x thin films were prepared by Electron Beam Evaporation using TiO as the starting material. The effect of the annealing temperature on the optical and electrical properties was investigated. The spectra of X-ray photoElectron spectroscopy reveal that Ti in the films mainly exist in the forms of Ti 2+ and Ti 3+ below 400 °C 24 h annealing. The charge transfer between different titanium ion contribute greatly to the color, absorption, and electrical resistance of the films.

  • high laser induced damage threshold hfo2 films prepared by ion assisted Electron Beam Evaporation
    Applied Surface Science, 2005
    Co-Authors: Dawei Zhang, Jianda Shao, Shuhai Fan, Yuanan Zhao, Weidong Gao, Ruiying Fan, Yingjian Wang, Zhengxiu Fan
    Abstract:

    HfO2 films were deposited by Electron Beam Evaporation with different deposition parameters. The properties such as refractive index, weak absorption, and laser induced damage thresholds (LIDTs) of these films have been investigated. It was found that when pulsed Nd:YAG 1064 nm laser is used to investigate LIDT of films: Metallic character is the main factor that influences LIDTs of films obtained from Hf starting material by ion-assisted reaction, and films prepared with higher momentum transfer parameter P have fewer metallic character; The ion-assisted reaction parameters are key points for preparing high LIDT films and if the parameters are chose properly, high LIDT films can be obtained. (c) 2004 Elsevier B.V. All rights reserved.

Zhengxiu Fan - One of the best experts on this subject based on the ideXlab platform.

  • al2o3 sio2 films prepared by Electron Beam Evaporation as uv antireflection coatings on 4h sic
    Applied Surface Science, 2008
    Co-Authors: Feng Zhang, Zhengxiu Fan, Huili Zhu, Weifeng Yang, Jianda Shao
    Abstract:

    Al2O3/SiO2 films have been deposited as UV antireflection coatings on 4H-SiC by Electron-Beam Evaporation and characterized by reflection spectrum, scanning Electron microscopy (SEM) and X-ray photoElectron spectroscopy (XPS). The reflectance of the Al2O3/SiO2 films is 0.33% and 10 times lower than that of a thermally grown SiO2 single layer at 276 nm. The films are amorphous in microstructure and characterize good adhesion to 4H-SiC substrate. XPS results indicate an abrupt interface between evaporated SiO2 and 4H-SiC substrate free of Si-suboxides. These results make the possibility for 4H-SiC based high performance UV optoElectronic devices with Al2O3/SiO2 films as antireflection coatings. (C) 2007 Elsevier B.V. All rights reserved.

  • optical and electrical properties of tiox thin films deposited by Electron Beam Evaporation
    Vacuum, 2007
    Co-Authors: Jianke Yao, Jianda Shao, Zhengxiu Fan
    Abstract:

    Abstract The TiO x thin films were prepared by Electron Beam Evaporation using TiO as the starting material. The effect of the annealing temperature on the optical and electrical properties was investigated. The spectra of X-ray photoElectron spectroscopy reveal that Ti in the films mainly exist in the forms of Ti 2+ and Ti 3+ below 400 °C 24 h annealing. The charge transfer between different titanium ion contribute greatly to the color, absorption, and electrical resistance of the films.

  • high laser induced damage threshold hfo2 films prepared by ion assisted Electron Beam Evaporation
    Applied Surface Science, 2005
    Co-Authors: Dawei Zhang, Jianda Shao, Shuhai Fan, Yuanan Zhao, Weidong Gao, Ruiying Fan, Yingjian Wang, Zhengxiu Fan
    Abstract:

    HfO2 films were deposited by Electron Beam Evaporation with different deposition parameters. The properties such as refractive index, weak absorption, and laser induced damage thresholds (LIDTs) of these films have been investigated. It was found that when pulsed Nd:YAG 1064 nm laser is used to investigate LIDT of films: Metallic character is the main factor that influences LIDTs of films obtained from Hf starting material by ion-assisted reaction, and films prepared with higher momentum transfer parameter P have fewer metallic character; The ion-assisted reaction parameters are key points for preparing high LIDT films and if the parameters are chose properly, high LIDT films can be obtained. (c) 2004 Elsevier B.V. All rights reserved.

Jun Tamaki - One of the best experts on this subject based on the ideXlab platform.