The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Sung Wng Kim - One of the best experts on this subject based on the ideXlab platform.

  • Te Monolayer-Driven Spontaneous van der Waals Epitaxy of Two-dimensional Pnictogen Chalcogenide Film on Sapphire
    AMER CHEMICAL SOC, 2018
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimen sional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and easily utilized for the developments of various 2D chalcogenide vdWE films through conventional thin-film fabrication technologies. © 2017 American Chemical Society2

  • te monolayer driven spontaneous van der waals epitaxy of two dimensional pnictogen chalcogenide film on sapphire
    Nano Letters, 2017
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimensional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and ea...

Pulickel M Ajayan - One of the best experts on this subject based on the ideXlab platform.

  • conversion of non van der waals solids to 2d transition metal Chalcogenides
    Nature, 2020
    Co-Authors: Shubin Yang, Jun Lou, Shuqing Zhang, Shuai Wang, Yongji Gong, Li Song, Xiaolong Zou, Pulickel M Ajayan
    Abstract:

    Although two-dimensional (2D) atomic layers, such as transition-metal Chalcogenides, have been widely synthesized using techniques such as exfoliation1–3 and vapour-phase growth4,5, it is still challenging to obtain phase-controlled 2D structures6–8. Here we demonstrate an effective synthesis strategy via the progressive transformation of non-van der Waals (non-vdW) solids to 2D vdW transition-metal chalcogenide layers with identified 2H (trigonal prismatic)/1T (octahedral) phases. The transformation, achieved by exposing non-vdW solids to chalcogen vapours, can be controlled using the enthalpies and vapour pressures of the reaction products. Heteroatom-substituted (such as yttrium and phosphorus) transition-metal Chalcogenides can also be synthesized in this way, thus enabling a generic synthesis approach to engineering phase-selected 2D transition-metal chalcogenide structures with good stability at high temperatures (up to 1,373 kelvin) and achieving high-throughput production of monolayers. We anticipate that these 2D transition-metal Chalcogenides will have broad applications for electronics, catalysis and energy storage. A synthetic approach is described, for efficiently converting non-van der Waals solids into two-dimensional van der Waals transition-metal chalcogenide layers with specific phases, enabling the high-throughput production of monolayers.

Jae-yeol Hwang - One of the best experts on this subject based on the ideXlab platform.

  • Te Monolayer-Driven Spontaneous van der Waals Epitaxy of Two-dimensional Pnictogen Chalcogenide Film on Sapphire
    AMER CHEMICAL SOC, 2018
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimen sional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and easily utilized for the developments of various 2D chalcogenide vdWE films through conventional thin-film fabrication technologies. © 2017 American Chemical Society2

  • te monolayer driven spontaneous van der waals epitaxy of two dimensional pnictogen chalcogenide film on sapphire
    Nano Letters, 2017
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimensional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and ea...

Shubin Yang - One of the best experts on this subject based on the ideXlab platform.

  • conversion of non van der waals solids to 2d transition metal Chalcogenides
    Nature, 2020
    Co-Authors: Shubin Yang, Jun Lou, Shuqing Zhang, Shuai Wang, Yongji Gong, Li Song, Xiaolong Zou, Pulickel M Ajayan
    Abstract:

    Although two-dimensional (2D) atomic layers, such as transition-metal Chalcogenides, have been widely synthesized using techniques such as exfoliation1–3 and vapour-phase growth4,5, it is still challenging to obtain phase-controlled 2D structures6–8. Here we demonstrate an effective synthesis strategy via the progressive transformation of non-van der Waals (non-vdW) solids to 2D vdW transition-metal chalcogenide layers with identified 2H (trigonal prismatic)/1T (octahedral) phases. The transformation, achieved by exposing non-vdW solids to chalcogen vapours, can be controlled using the enthalpies and vapour pressures of the reaction products. Heteroatom-substituted (such as yttrium and phosphorus) transition-metal Chalcogenides can also be synthesized in this way, thus enabling a generic synthesis approach to engineering phase-selected 2D transition-metal chalcogenide structures with good stability at high temperatures (up to 1,373 kelvin) and achieving high-throughput production of monolayers. We anticipate that these 2D transition-metal Chalcogenides will have broad applications for electronics, catalysis and energy storage. A synthetic approach is described, for efficiently converting non-van der Waals solids into two-dimensional van der Waals transition-metal chalcogenide layers with specific phases, enabling the high-throughput production of monolayers.

Young-min Kim - One of the best experts on this subject based on the ideXlab platform.

  • Te Monolayer-Driven Spontaneous van der Waals Epitaxy of Two-dimensional Pnictogen Chalcogenide Film on Sapphire
    AMER CHEMICAL SOC, 2018
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimen sional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and easily utilized for the developments of various 2D chalcogenide vdWE films through conventional thin-film fabrication technologies. © 2017 American Chemical Society2

  • te monolayer driven spontaneous van der waals epitaxy of two dimensional pnictogen chalcogenide film on sapphire
    Nano Letters, 2017
    Co-Authors: Jae-yeol Hwang, Young-min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
    Abstract:

    Demands on high-quality layer structured two-dimensional (2D) thin films such as pnictogen Chalcogenides and transition metal diChalcogenides are growing due to the findings of exotic physical properties and potentials for device applications. However, the difficulties in controlling epitaxial growth and the unclear understanding of van der Waals epitaxy (vdWE) for a 2D chalcogenide film on a three-dimensional (3D) substrate have been major obstacles for the further advances of 2D materials. Here, we exploit the spontaneous vdWE of a high-quality 2D chalcogenide (Bi0.5Sb1.5Te3) film by the chalcogen-driven surface reconstruction of a conventional 3D sapphire substrate. It is verified that the in situ formation of a pseudomorphic Te atomic monolayer on the surface of sapphire, which results in a dangling bond-free surface, allows the spontaneous vdWE of 2D chalcogenide film. Since this route uses the natural surface reconstruction of sapphire with chalcogen under vacuum condition, it can be scalable and ea...