The Nature of Oxide Surfaces: Topographic and Electronic Structure

1993 ◽  
Vol 51 ◽  
pp. 966-967
Author(s):  
Dawn A. Bonnell ◽  
Yong Liang
Keyword(s):  
Transition Metal Oxides ◽  
Electronic Structures ◽  
Recent Progress ◽  
Spatial Localization ◽  
Level Of Detail ◽  
Scanning Tunneling ◽  
Oxide Surfaces ◽  
Tunneling Microscopy ◽  
Considerable Effort ◽  
Complete Understanding

Recent progress in the application of scanning tunneling microscopy (STM) and tunneling spectroscopy (STS) to oxide surfaces has allowed issues of image formation mechanism and spatial resolution limitations to be addressed. As the STM analyses of oxide surfaces continues, it is becoming clear that the geometric and electronic structures of these surfaces are intrinsically complex. Since STM requires conductivity, the oxides in question are transition metal oxides that accommodate aliovalent dopants or nonstoichiometry to produce mobile carriers. To date, considerable effort has been directed toward probing the structures and reactivities of ZnO polar and nonpolar surfaces, TiO2 (110) and (001) surfaces and the SrTiO3 (001) surface, with a view towards integrating these results with the vast amount of previous surface analysis (LEED and photoemission) to build a more complete understanding of these surfaces. However, the spatial localization of the STM/STS provides a level of detail that leads to conclusions somewhat different from those made earlier.

scholarly journals Electronic structures and unusually robust bandgap in an ultrahigh-mobility layered oxide semiconductor, Bi2O2Se

2018 ◽  
Vol 4 (9) ◽  
pp. eaat8355 ◽  
Author(s):  
Cheng Chen ◽  
Meixiao Wang ◽  
Jinxiong Wu ◽  
Huixia Fu ◽  
Haifeng Yang ◽  
...  
Keyword(s):  
Electronic Structures ◽  
High Mobility ◽  
Sample Surface ◽  
Substrate Material ◽  
Oxide Semiconductor ◽  
Scanning Tunneling ◽  
Modern World ◽  
Fermi Velocity ◽  
Tunneling Microscopy ◽  
Spatial Uniformity

Semiconductors are essential materials that affect our everyday life in the modern world. Two-dimensional semiconductors with high mobility and moderate bandgap are particularly attractive today because of their potential application in fast, low-power, and ultrasmall/thin electronic devices. We investigate the electronic structures of a new layered air-stable oxide semiconductor, Bi2O2Se, with ultrahigh mobility (~2.8 × 105cm2/V⋅s at 2.0 K) and moderate bandgap (~0.8 eV). Combining angle-resolved photoemission spectroscopy and scanning tunneling microscopy, we mapped out the complete band structures of Bi2O2Se with key parameters (for example, effective mass, Fermi velocity, and bandgap). The unusual spatial uniformity of the bandgap without undesired in-gap states on the sample surface with up to ~50% defects makes Bi2O2Se an ideal semiconductor for future electronic applications. In addition, the structural compatibility between Bi2O2Se and interesting perovskite oxides (for example, cuprate high–transition temperature superconductors and commonly used substrate material SrTiO3) further makes heterostructures between Bi2O2Se and these oxides possible platforms for realizing novel physical phenomena, such as topological superconductivity, Josephson junction field-effect transistor, new superconducting optoelectronics, and novel lasers.

How to realize ultimate spatial and temporal resolutions by laser-combined scanning tunneling microscopy?

2005 ◽  
Vol 901 ◽  
Author(s):  
Hidemi Shigekawa ◽  
Osamu Takeuchi ◽  
Masahiro Aoyama ◽  
Yasuhiko Terada ◽  
Hiroyuki Kondo ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Pulse Laser ◽  
Electronic Structures ◽  
Femtosecond Pulse ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Optical Pump ◽  
Pump Probe ◽  
Probe Technique ◽  
Femtosecond Pulse Laser

AbstractBy combining scanning tunneling microscopy (STM) and the optical pump-probe technique using a femtosecond pulse laser, we have developed a new microscopy, shaken pulse-pair-excited STM (SPPX-STM), that enables us to observe the dynamics of electronic structures with the ultimate spatial and temporal resolutions.

scholarly journals Rational synthesis of atomically precise graphene nanoribbons directly on metal oxide surfaces

Science ◽  
2020 ◽  
Vol 369 (6503) ◽  
pp. 571-575 ◽  
Author(s):  
Marek Kolmer ◽  
Ann-Kristin Steiner ◽  
Irena Izydorczyk ◽  
Wonhee Ko ◽  
Mads Engelund ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Graphene Nanoribbons ◽  
Scanning Tunneling ◽  
Oxide Surfaces ◽  
Tunneling Microscopy ◽  
Metal Oxide Surfaces ◽  
Metallic Substrates ◽  
Rutile Titanium Dioxide ◽  
Thermally Triggered ◽  
Synthesis Approach

Atomically precise graphene nanoribbons (GNRs) attract great interest because of their highly tunable electronic, optical, and transport properties. However, on-surface synthesis of GNRs is typically based on metal surface–assisted chemical reactions, where metallic substrates strongly screen their designer electronic properties and limit further applications. Here, we present an on-surface synthesis approach to forming atomically precise GNRs directly on semiconducting metal oxide surfaces. The thermally triggered multistep transformations preprogrammed in our precursors’ design rely on highly selective and sequential activations of carbon-bromine (C-Br) and carbon-fluorine (C-F) bonds and cyclodehydrogenation. The formation of planar armchair GNRs terminated by well-defined zigzag ends is confirmed by scanning tunneling microscopy and spectroscopy, which also reveal weak interaction between GNRs and the rutile titanium dioxide substrate.

Recent progress in photon scanning tunneling microscopy

1992 ◽  
Author(s):  
Jean-Pierre Goudonnet ◽  
Laurent Salomon ◽  
Frederique de Fornel ◽  
Eric Bourillot ◽  
P. Adam ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Recent Progress ◽  
Scanning Tunneling ◽  
Tunneling Microscopy
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