The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform

Andréas Klein - One of the best experts on this subject based on the ideXlab platform.

  • Barrier height at (Ba,Sr)TiO3/Pt interfaces studied by photoemission
    Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008
    Co-Authors: R. Schafranek, Sandrine Payan, Mario Maglione, Andréas Klein
    Abstract:

    The interface formation of Nb-doped SrTiO3 single crystals and (Ba,Sr)TiO3 thin films with Pt has been studied by using photoelectron spectroscopy with in situ sample preparation. For the single crystal sample, a Schottky barrier height for electrons of 0.5–0.6 eV is determined after deposition of Pt in vacuum environment. After annealing in 0.05 Pa oxygen pressure, a strong increase in the barrier height to >=1.2 eV is observed. X-ray induced photovoltages of up to 0.7 eV are observed in this case and have to be taken into account for a proper determination of the barrier height. A subsequent annealing in vacuum reduces the barrier again. Hence, the barrier height can be reversibly switched between an oxidized state with a large barrier height and a reduced state with a low barrier height. Quantitative analysis of the barrier heights indicates that the changes are related to the changes of Interfacial Defect concentration. Due to the occurrence of a Ti3+ related signal, the Defects are identified as oxygen vacancies. The same effects are observed at interfaces between Pt and (Ba,Sr)TiO3 thin films with a smaller absolute value of the barrier height in the oxidized state of ~1 eV. Deposition of (Ba,Sr)TiO3 onto a metallic Pt substrate also results in a barrier height of 1.0 eV.

R. Schafranek - One of the best experts on this subject based on the ideXlab platform.

  • Barrier height at (Ba,Sr)TiO3/Pt interfaces studied by photoemission
    Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008
    Co-Authors: R. Schafranek, Sandrine Payan, Mario Maglione, Andréas Klein
    Abstract:

    The interface formation of Nb-doped SrTiO3 single crystals and (Ba,Sr)TiO3 thin films with Pt has been studied by using photoelectron spectroscopy with in situ sample preparation. For the single crystal sample, a Schottky barrier height for electrons of 0.5–0.6 eV is determined after deposition of Pt in vacuum environment. After annealing in 0.05 Pa oxygen pressure, a strong increase in the barrier height to >=1.2 eV is observed. X-ray induced photovoltages of up to 0.7 eV are observed in this case and have to be taken into account for a proper determination of the barrier height. A subsequent annealing in vacuum reduces the barrier again. Hence, the barrier height can be reversibly switched between an oxidized state with a large barrier height and a reduced state with a low barrier height. Quantitative analysis of the barrier heights indicates that the changes are related to the changes of Interfacial Defect concentration. Due to the occurrence of a Ti3+ related signal, the Defects are identified as oxygen vacancies. The same effects are observed at interfaces between Pt and (Ba,Sr)TiO3 thin films with a smaller absolute value of the barrier height in the oxidized state of ~1 eV. Deposition of (Ba,Sr)TiO3 onto a metallic Pt substrate also results in a barrier height of 1.0 eV.

Xiumei Wei - One of the best experts on this subject based on the ideXlab platform.

  • Interfacial Defect engineering the electronic states and photocatalytic properties of blue phosphorus ws2 heterostructures
    Journal of Alloys and Compounds, 2021
    Co-Authors: Jingnan Wang, Yuhong Huang, Gangqiang Zhu, Jian-min Zhang, Xiumei Wei
    Abstract:

    Abstract The influences of the Interfacial Defects on the electronic states and photocatalytic properties of blue phosphorus/tungsten disulfide (BlueP/WS2) are studied by first-principle calculations. The results show that the BlueP/WS2 (model II) exhibit a direct band gap of 1.77 eV. The optical absorption of the BlueP/WS2 heterostructure is enhanced and the edge is red-shifted with respect to BlueP and WS2. The band arrangements could be well adjusted by doping C, Si, Ge, Sn, N, P, As, Sb, Bi, O, S, Se and Te at the interface. The band alignment of M-BlueP/WS2 (M = C, Si, Ge, Sn, Sb, S, Bi) and BlueP/M-WS2 (M = N, P) are changed from type I to type-II. C-BlueP/WS2, S-BlueP/WS2, BlueP/N-WS2 and BlueP/P-WS2 can conduct the full water decomposition. More charge transfer occurs in S-BlueP/WS2, BlueP/N-WS2 and BlueP/P-WS2, leading to stronger built-in electric field. This is beneficial to the separation of photo-generated electron-hole pairs and the enhanced photocatalytic activity. Therefore, the electronic and photocatalytic properties of the heterostructures can be effectively modulated by Interfacial Defects.

  • Interfacial Defect engineering the electronic states and photocatalytic properties of blue phosphorus/WS2 heterostructures
    Journal of Alloys and Compounds, 1
    Co-Authors: Jingnan Wang, Yuhong Huang, Gangqiang Zhu, Jian-min Zhang, Xiumei Wei
    Abstract:

    Abstract The influences of the Interfacial Defects on the electronic states and photocatalytic properties of blue phosphorus/tungsten disulfide (BlueP/WS2) are studied by first-principle calculations. The results show that the BlueP/WS2 (model II) exhibit a direct band gap of 1.77 eV. The optical absorption of the BlueP/WS2 heterostructure is enhanced and the edge is red-shifted with respect to BlueP and WS2. The band arrangements could be well adjusted by doping C, Si, Ge, Sn, N, P, As, Sb, Bi, O, S, Se and Te at the interface. The band alignment of M-BlueP/WS2 (M = C, Si, Ge, Sn, Sb, S, Bi) and BlueP/M-WS2 (M = N, P) are changed from type I to type-II. C-BlueP/WS2, S-BlueP/WS2, BlueP/N-WS2 and BlueP/P-WS2 can conduct the full water decomposition. More charge transfer occurs in S-BlueP/WS2, BlueP/N-WS2 and BlueP/P-WS2, leading to stronger built-in electric field. This is beneficial to the separation of photo-generated electron-hole pairs and the enhanced photocatalytic activity. Therefore, the electronic and photocatalytic properties of the heterostructures can be effectively modulated by Interfacial Defects.

Sandrine Payan - One of the best experts on this subject based on the ideXlab platform.

  • Barrier height at (Ba,Sr)TiO3/Pt interfaces studied by photoemission
    Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008
    Co-Authors: R. Schafranek, Sandrine Payan, Mario Maglione, Andréas Klein
    Abstract:

    The interface formation of Nb-doped SrTiO3 single crystals and (Ba,Sr)TiO3 thin films with Pt has been studied by using photoelectron spectroscopy with in situ sample preparation. For the single crystal sample, a Schottky barrier height for electrons of 0.5–0.6 eV is determined after deposition of Pt in vacuum environment. After annealing in 0.05 Pa oxygen pressure, a strong increase in the barrier height to >=1.2 eV is observed. X-ray induced photovoltages of up to 0.7 eV are observed in this case and have to be taken into account for a proper determination of the barrier height. A subsequent annealing in vacuum reduces the barrier again. Hence, the barrier height can be reversibly switched between an oxidized state with a large barrier height and a reduced state with a low barrier height. Quantitative analysis of the barrier heights indicates that the changes are related to the changes of Interfacial Defect concentration. Due to the occurrence of a Ti3+ related signal, the Defects are identified as oxygen vacancies. The same effects are observed at interfaces between Pt and (Ba,Sr)TiO3 thin films with a smaller absolute value of the barrier height in the oxidized state of ~1 eV. Deposition of (Ba,Sr)TiO3 onto a metallic Pt substrate also results in a barrier height of 1.0 eV.

Mario Maglione - One of the best experts on this subject based on the ideXlab platform.

  • Barrier height at (Ba,Sr)TiO3/Pt interfaces studied by photoemission
    Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008
    Co-Authors: R. Schafranek, Sandrine Payan, Mario Maglione, Andréas Klein
    Abstract:

    The interface formation of Nb-doped SrTiO3 single crystals and (Ba,Sr)TiO3 thin films with Pt has been studied by using photoelectron spectroscopy with in situ sample preparation. For the single crystal sample, a Schottky barrier height for electrons of 0.5–0.6 eV is determined after deposition of Pt in vacuum environment. After annealing in 0.05 Pa oxygen pressure, a strong increase in the barrier height to >=1.2 eV is observed. X-ray induced photovoltages of up to 0.7 eV are observed in this case and have to be taken into account for a proper determination of the barrier height. A subsequent annealing in vacuum reduces the barrier again. Hence, the barrier height can be reversibly switched between an oxidized state with a large barrier height and a reduced state with a low barrier height. Quantitative analysis of the barrier heights indicates that the changes are related to the changes of Interfacial Defect concentration. Due to the occurrence of a Ti3+ related signal, the Defects are identified as oxygen vacancies. The same effects are observed at interfaces between Pt and (Ba,Sr)TiO3 thin films with a smaller absolute value of the barrier height in the oxidized state of ~1 eV. Deposition of (Ba,Sr)TiO3 onto a metallic Pt substrate also results in a barrier height of 1.0 eV.