Publications by authors named "Ying Hoi Lai"

We have developed an incandescent Mo source to fabricate large-area single-crystalline MoSe thin films. The as-grown MoSe thin films were characterized using transmission electron microscopy, energy dispersive x-ray spectroscopy, atomic force microscopy, Raman spectroscopy, photoluminescence (PL), reflection high energy electron diffraction (RHEED) and angular resolved photoemission spectroscopy (ARPES). A new Raman characteristic peak at 1591 cm was identified.

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Cu doping of ZnTe, which is an important semiconductor for various optoelectronic applications, has been successfully achieved previously by several techniques. However, besides its electrical transport characteristics, other physical and chemical properties of heavily Cu-doped ZnTe have not been reported. We found an interesting self-assembled formation of crystalline well-aligned Cu-Te nano-rods near the surface of heavily Cu-doped ZnTe thin films grown via the molecular beam epitaxy technique.

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We have investigated the anisotropic magnetic responses of a 2D-superconducting Bi2Te3/FeTe heterostructure. Cross-sectional STEM imaging revealed that the excess Fe atoms in the FeTe layer occupy specific interstitial sites. They were found to show strong anisotropic magnetic responses under a magnetic field either perpendicular or parallel to the sample surface.

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Article Synopsis
  • - The study explores superconductivity at the interface of a topological insulator (Bi2Te3) and an iron-chalcogenide (FeTe), revealing that superconductivity occurs even with a very thin Bi2Te3 layer.
  • - Evidence suggests the observed superconductivity is two-dimensional, with a maximum transition temperature of about 12 K and characteristics indicating a Berezinsky-Kosterlitz-Thouless transition.
  • - This research highlights the potential for creating Majorana fermions in this heterostructure, combining interface superconductivity with Dirac surface states.
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We present a study of the surface reactivity of a Pd/Bi2Te3 thin film heterostructure. The topological surface states from Bi2Te3, being delocalized and robust owing to their topological natures, were found to act as an effective electron bath that significantly enhances the surface reactivity of palladium in the presence of two oxidizing agents, oxygen and tellurium respectively, which is consistent with a theoretical calculation. The surface reactivity of the adsorbed tellurium on this heterostructure is also intensified possibly benefitted from the effective transfer of the bath electrons.

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