Download or read book Scanning Tunneling Microscopic Study of Defects and Heterointerfaces of Transition Metal Dichalcogenides written by 原梦菲 and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition metal Dichalcogenides and the Scanning Tunnelling Microscope written by John Christopher Caulfield and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scanning Tunneling Microscopy Studies of Defects in Semiconductors written by Anne Laura Benjamin and published by . This book was released on 2018 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses scanning tunneling microscopy (STM) studies of metal defects in GaAs(110). Single-atom defects are useful for their potential applications in developing nano-scale miniaturized or new types of optical, magnetic, and electronic devices, as well as expanding our understanding of atomic-scale interactions. STM is used to measure physical and electronic properties of surface and near-surface materials with atomic resolution, but affects the properties of defects being studied.

Download or read book Scanning Tunneling Microscopy of Semiconductors written by Jun Fei Zheng and published by . This book was released on 1994 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scanning Tunneling Microscopy Study of Defects and Devices in Topological Materials written by Michael Gottschalk and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological phases in condensed matter systems have received tremendous interest in the past two decades. Theoretical work has shown how topological invariants can be calculated from the band structures in a wide range of insulating systems that contain an energy gap. Broadly speaking, these topological invariants are quantities that are invariant under continuous deformation so long as specific symmetries hold and the energy gap stays open. What separates topological states of matter from traditional phases is the concept of bulk-boundary correspondence. The topology of the vacuum is trivial, so if the bulk of a material is topologically non-trivial, the energy gap must close at the boundary between the two. This creates conducting states at the boundaries, or edges, of the material; the conducting states within the gap have specific properties. Strong, 3Dtopological insulators, such as Bi2Se3 , are materials that are insulating in the bulk with conducting surface states due to bulk-boundary correspondence. The surface states are topologically protected from local perturbations and feature a linear dispersion relation, known as the Dirac cone. Bi2Se3is one of the most widely studied topological insulators due to the relative simplicity of its band structure with a single Dirac cone. In this work, I study the effects of N2 gas on the surface states of Bi2Se3 , which appears to p-type dope the density of states spectra measured with a scanning tunneling microscope. Topological superconductors have also garnered great interest for their potential applications in topological quantum computing. The second half of this dissertation is focused on describing, fabricating, and measuring a potential platform for a possible topological superconducting state known as a Majorana zero mode. These devices feature Nb sputtered onBi2Se3 that is patterned into Josephson junctions with e-beam lithography techniques.

Download or read book Scanning Tunneling Microscopy of the Transition Metal Dichalcogenide Tantalum Disulfide written by Wenhai Han and published by . This book was released on 1994 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engineering of Mixed Phase Transition Metal Dichalcogenide Materials written by William R. Scougale and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of smaller, and new computation devices continues to drive interest in the fundamental physical sciences and their possible applications to improved computation capability. With the infancy of quantum computing, much research has been devoted to developing greater noise tolerance in qubit technologies. In addition, other avenues for improvement remain for classical computing, particularly with scaling electronic systems from 3D to 2D. Recently, transition metal dichalcogenide materials have drawn interest due to their extensive variety of material properties, stable chemical state, and comparably easy exfoliation. These materials are routinely reduced to 2D sheets and can be stacked to produce devices. Unanticipated physical phenomena have been observed in such stacked layers, as seen with magic angle graphene. These properties are driven by moiré interactions between the layers, which can vary continuously with parameters such as lattice size and shape, twist angle, and strain. This produces an incredible number of possible combinations of materials and moiré patterns, all of which could produce useful properties. In this work, a mixed phase growth approach to local nanoscopic measurements is detailed. In particular, it is found that for tungsten disulfide these mixed phase crystals are ideal for examining a broad variety of phase mixing and moiré interactions. Finally, a few physical systems are examined in detail including a 2M-2H vertical heterostructure moiré pattern, the appearance of stripe phase moiré patterning not predicted by rigid modeling, and finally the realization of a possible Kondo Lattice on a 2M-2M-2H moiré region.

Download or read book Scanning Tunneling Microscopy Investigations of Metal Dichalcogenide Materials written by and published by . This book was released on 1993 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) have been used to characterize the atomic level structure of electronic properties, reactivity and wear of metal dichalcogenide materials that are or have potential as solid state lubricants. Single crystals Of MoS2, Ni(x)Mo(l-x) S2, MoS(2-x)Se(x) and MoS(2-x)Te(x) have been prepared to determine how chemical modifications affect the local structure and electronic properties of this lubricant. STM images of Ni-doped MoS2 show localized electronic states due to the Ni atoms, while images of Se- and Te-doped materials indicate that anion substitution is electronically delocalized. AFM studies of Te-doped MoS2 show, however, that the tellurium dopants form atomic scale structural protrusions that may reduce sliding friction. AFM has also been used to characterize nanometer scale wear and oxidation on MoS2 and NbSe2 surfaces. In atmosphere at room-temperature AFM studies showed that NbSe2 wears approximately three times faster than MoS2. Furthermore, oxidation studies demonstrated that NbSe2 was significantly more reactive than MoS2 with molecular oxygen. These results indicate that the intrinsic stability of the MoS2 surface make it an effective lubricant, AFM was also used to elucidate the growth of MoO3 on the surface Of MoS2 during oxidation, and to study wear properties of these MoO3 crystallites. The AFM tip was used to define lines with 10 nm resolution in MoO3 and to manipulate distinct MoO3 structures on the MoS2 surface. In addition, metal- substitution in TaS2 has been studied systematically using STM and theoretical methods.

Download or read book Scanning Tunneling Microscopy and Spectroscopy written by Chen Wang and published by . This book was released on 1991 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scanning Tunneling Microscope Studies of Surface Defects written by and published by . This book was released on 1991 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Probing Transition Metal Dichalcogenide Monolayers and Heterostructures by Optical Spectroscopy and Scanning Tunneling Spectroscopy written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We then compare our results with the exciton lifetime in MoS2/WS2 and MoSe2/WSe2 heterostructures. In TMDC/TMDC heterostructures, the decrease in exciton lifetime is twice that in WS2/graphene heterostructures and due predominantly to charge transfer between the layers. Finally, we probe the band alignment in MoS2/WS2 heterostructures using scanning tunneling microscopy (STM) and spectroscopy (STS).We confirm the monolayer band gaps and the predicted type II band alignment in the heterostructure. Drawing from all the research presented, we arrive at a favorable conclusion about the viability of TMDC based devices.

Download or read book Scanning Tunneling Microscopy of Two dimensional Materials written by Grady A. Gambrel and published by . This book was released on 2017 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional materials are of fundamental and practical interest due to the unique properties they exhibit. As they are only one layer or one atom thick, their physical and electronic properties are sensitive to their local environment, and may be manipulated by engineering variations within the materials. Incorporating these materials into electronic devices requires that their interactions are well understood so that they behave as predicted. For this reason, the study of defects, likely contaminants, and engineered structures is worthwhile. The scanning tunneling microscope is of particular use in such experiments as it can be used to characterize the atomic structure and locally measure the electronic properties of samples. Graphene islands were grown on Cu(111) in ultrahigh vacuum to study graphene/copper interactions with minimal surface adsorbates. Using in situ low-temperature scanning tunneling microscopy (STM), both the physical and electronic structure were measured with atomic spatial resolution and compared with those of clean copper regions. These measurements indicate a decrease in the work function relative to clean Cu(111) and reduced coupling of surface electronic states to the bulk. Other measurements find that both the band edge and effective mass of Shockley surface state electrons are infuenced by the graphene layer. Similarly, single-layer germanene was grown on and measured on Cu(111). A competing alloy process which forms Cu2Ge restricts notable germanene coverage to a substrate temperature range between 40 degrees and 150 degrees Celsius. Atomic resolution imaging and tunneling spectroscopy are used to distinguish germanene and Cu2Ge regions, and probe the interaction of both with the Cu(111) substrate. Germanene was found to be weakly coupled to the Cu(111), maintaining an incommensurate 3.8 Angstrom lattice but lack any clear signatures of the Dirac point. In contrast, a 4.4 Angstrom lattice is observed on Cu2Ge that is commensurate with a v3 x v3 R30 reconstruction of Cu(111), and distinct unoccupied electronic states are observed well above the sample Fermi level.

Download or read book Low Temperature Scanning Tunneling Microscopy Studies of the Surface and Impurity States in Narrow Gap Semiconductors written by Sergei Urazhdin and published by . This book was released on 2002 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scanning Tunneling Microscopy Studies of Growth and Adsorption on Transition Metal Surfaces written by Morten Østergaard Pedersen and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Two Dimensional Materials by Scanning Probe Microscopy written by Ryan Plumadore and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores structural and electronic properties of layered materials at the nanometre scale. Room temperature and low temperature ultrahigh vacuum scanning probe microscopy (scanning tunneling microscopy, scanning tunneling spectroscopy, atomic force microscopy) is used as the primary characterization method. The main findings in this thesis are: (a) observations of the atomic lattice and imaging local lattice defects of semiconducting ReS2 by scanning tunneling microscopy, (b) measurement of the electronic band gap of ReS2 by scanning tunneling spectroscopy, and (c) scanning tunneling microscopy study of 1T-TaS2 lattice and chemically functionalizing its defects with magnetic molecules.

Download or read book ETCMOS 2016 Vol 6 Flexible Electronics and Materials Track written by ETCMOS and published by CMOS Emerging Technologies Research. This book was released on 2016-05-26 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presentation slides from the Flexible Electronics and Materials track at the ETCMOS 2016 conference in Montreal, May 25-27, 2016

Download or read book Scanning Tunneling Microscope Study of the Superconductor insulator Transition in Molybdenum Nitride written by Hong Zheng and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: