Sökning: "tunneling microscopy"
Visar resultat 1 - 5 av 81 avhandlingar innehållade orden tunneling microscopy.
1. Theoretical modeling of scanning tunneling microscopy
Sammanfattning : The main body of this thesis describes how to calculate scanning tunneling microscopy (STM) images from first-principles methods. The theory is based on localized orbital density functional theory (DFT), whose limitations for large-vacuum STM models are resolved by propagating localized-basis wave functions close to the surface into the vacuum region in real space. LÄS MER
2. Scanning Tunneling Microscopy Induced Luminescence Studies of Semiconductor Nanostructures
Sammanfattning : This thesis treats scanning tunneling luminescence (STL) investigations of semiconductor nanostructures. The STL technique combines scanning tunneling microscopy (STM) with detection of photons, induced by the tunneling electrons. The high spatial resolution in STM and the local excitation allow for optical investigations on the nanometer-scale. LÄS MER
3. On the Properties of Some Strongly Correlated Systems - Analytical and Numerical Studies
Sammanfattning : This thesis is dedicated to analytical and numerical studiesof a few models of strongly correlated systems and thedevelopment of techniques for such studies. The common name"strongly correlated" refers to systems in which theinteractions (correlations) between the constituent particleslead to nontrivial properties, such as various types ofmagnetism, superconductivity, and exotic phases. LÄS MER
4. Transmission Electron Microscopy of Semiconductor Nanowires
Sammanfattning : Semiconductor nanowires are studied by using transmission electron microscopy (TEM) based methods in this work. In the first section, the growth mechanism of gallium arsenide nanowires grown by chemical beam epitaxy is investigated. The nanowires are epitaxially grown from a gallium arsenide substrate by using gold seed particles as catalysts. LÄS MER
5. Electronic and Geometrical Structure of Phthalocyanines on Surfaces : An Electron Spectroscopy and Scanning Tunneling Microscopy Study
Sammanfattning : Core- and Valence Photoelectron Spectroscopy (PES), X-ray- and Ultraviolet-Visible Absorption Spectroscopy (XAS and UV-Vis), Scanning Tunneling Microscopy (STM) and Density Functional Theory (DFT) calculations are used to study the electronic and geometrical structure of a class of macro-cyclic molecules, Phthalocyanines (Pc), on surfaces. These molecules are widely studied due to their application in many different fields. LÄS MER