LEED Study of the Structure of $Si(111)-\left( {2\sqrt 3 \times 2\sqrt 3 } \right)R30^{\circ }-4B+14Sn$ Phase

ORAL

Abstract

While doping of bulk materials to control their properties has been hugely successful, doping of inherently low-dimensional surface-based electronic structures remains a challenge: dopant atoms not only affect the electronic carrier density but also significantly disrupt the surface atomic structure, and often lead to localized changes of atomic and electronic properties. We developed a modulation doping approach to dope surface structures with the dopants that are located below the surface of a two-layer thick Sn film on Si(111). The doped Sn film exhibits a temperature dependent structural and electronic phase transition that is absent in the undoped structure. In this study, we have used low-energy electron diffraction (LEED) to determine the surface structure. The LEED experiment was performed at 90 K. The energy range was 40-500 eV, for a total of 7126eV from 20 independent beams. The structure models considered include those based on the scanning tunneling microscopy (STM) images and density functional theory (DFT) calculations. The best agreement obtained was proposed in a recent DFT study produces a Pendry R-factor of 0.36. However, the level of agreement is not yet convincing and many more structure models are being tested.

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Authors

  • Ying-Tzu Huang

    Department of Physics, Penn State University

  • Cora Dvorkin

    Pennsylvania State University, Department of Physics, Penn State University, Harvard University

  • Weisong Tu

    Department of Physics and Astronomy, University of Tennessee

  • Daniel Mulugeta

    Department of Physics and Astronomy, University of Tennessee

  • Paul Snijders

    Oak Ridge National Laboratory

  • Eva Andrei

    National Center for Biotechnology Information, NIH, Pennsylvania State Univ, Department of Physics, Temple University, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Science, Department of Physics, Boise State University, National Synchrotron Light Source, Brookhaven National Laboratory, York Univ, Erciyes Univ, Chinese Academy of Sciences Hefei, Pennsylvania State Univ and USTC, Heidelberg Institute for Theoretical Studies, MIT, Harvard, Penn State University, Canadian Institute for Theoretical Astrophysics, The Pennsylvania State University, University Park, Pennsylvania State University, Penn State, Department of Physics, Penn State University, University Park, USA, National Institute for Material Science, 1-1 Namiki, Tsukuba, Japan, Carnegie Mellon University, IPICYT, Mexico, Shinshu University, Japan, Universidad Carlos III de Madrid, Spain, Universidade de Sao Paulo, Brazil, Tsinghua University, China, American Physical Society, Appalachian State University, West Chester Univ, Lehigh University, Drew University, University of Balearics Islands, Roanoke College, NIST, Tulane Univ, Shanghai Jiao Tong Univ, Zhejiang Univ, National Institute of Standards and Technology, Department of Physics, The Pennsylvania State University, Department of Electrical Engineering, The Pennsylvania State University, Department of Materials Science and Engineering, the Pennsylvania State University, Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, International Center for Quantum Materials, Peking University, Villanova University, West Virginia University, Institut Lumiere Matiere, PSU, Oak Ridge National Laboratory, Towson Univ, CINVESTAV-Queretaro, Prince George Community College, Howard University, Towson University, The Pennsylvania State University, Hokkaido Univ, Cinvestav-Unidad Queretaro, Queretaro-76230, Mexico, Lawrence Livermore National Laboratory, Osaka University, Penn State Univ, Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, Department of Anthropology, The Pennsylvania State University, ILM Universit\'{e} Lyon 1, Moravian College, Bloomsburg Univ, Universit\"at Bielefeld, Syracuse University, Alabama A\&M University, Indiana University of PA, University of Denver, IUP, University of Nebraska, University of Science and Technology of China, Seoul National University, Soochow University China, US Army Research Laboratory, Drexel University, University of Stuttgart, Youngstown State University, University of Surrey, Department of Chemistry and Biochemistry, University of Maryland, College Park, Department of Mathematics, West Virginia University, University of Delaware, Physics Department, The Pennsylvania State University, 104 Davey Lab, University Park, PA, 16802, USA, Department of Physics and Astronomy, West Virginia University, McMaster University, University of Toronto, The University of Texas at Austin, Army Research Lab, Adelphi MD, University of Connecticut, Notre Dame, University of Maryland, Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Rutgers University

  • Hanno Weitering

    Department of Physics and Astronomy, University of Tennessee