In the past decade, driven by the demand for materials with high performance for next-generation semiconductor devices (e.g., for quantum computing), the exploration of III-V semiconductor materials and the design of improved devices based on these materials has extended to the nanometer scale, with several highlights in the studies of quantum wells, quantum dots, and nanowires (NW) in recent years. On the path of seeking smaller scale devices, the lateral scale is usually limited by the spatial resolution of the lithographic processes. Now, the challenge lies in the combination of semiconductor nanoscale structure with the desired electronic properties. Scaling down material synthesis to crystalline structures of only few atoms in size and precisely positioned in device configuration has not been realized so far. Moreover, the compatibility for large-scale industrial device processing is also challenging. In this dissertation, I present the surface characterization and studies of the modification of nanostructures on III-V semiconductor surfaces, with the techniques of low temperature scanning tunneling microscopy/spectroscopy (LT-STM/S) and X-ray photoelectron spectroscopy (XPS). Two main topics are Bi incorporation in GaAs (and InAs) surfaces and self-driven formation of nanostructures with atomic-scale precision. Different zinc blende and wurtzite crystal planes have been investigated, including the {11-20}- type facet which for GaAs and InAs uniquely exists on the side walls of NWs and nanoplatelets. The utilization of the tailored facets of NWs as templates for Bi-induced nanostructure formation has been explored as well. Bi-introduced low-dimensional nanostructures and exotic electronic states in III-V semiconductor systems have been investigated. The covalent bonds of Bi atoms in the self-formed Bi nanostructures on III-V substrates can vary depending on the substrate template and preparation condition, such as the Ga-Bi bonds in the 1D chain and 2D island nanostructures on Wz{11-20}-type facets on GaAs NWs. The possibility of tuning the self-formed III-V:Bi nanostructures in a more controllable way has been explored in this thesis. A significant high coverage of Bi on III-V semiconductor surface has been achieved. The observed variable bandgap and Bi-induced surface states are promising for applications in surface bandgap engineering and quantum technology components.

Fabrication technologies for nanostructured devices have been developed recently, and the electrical and optical properties of such nanostructures are a subject of advanced research. This book describes the different approaches to spectroscopic microscopy, i.e., Electron Beam Probe Spectroscopy, Spectroscopic Photoelectron Microscopy, and Scanning Probe Spectroscopy. It will be useful as a compact source of reference for the experienced reseracher, taking into account at the same time the needs of postgraduate students and nonspecialist researchers by using a tutorial approach throughout.

June 05-06, 2017 Milan, Italy Key Topics : Nanoscience and Technology, Nano Medicine, Nano Electronics, Molecular Nanotechnology, Nano Toxicology, Nano Topography, Nano Fluidics, Nano Weapons, Nano Biotechnology, Nanotechnology in Water treatment, Nano Composites, Nanoscale, Advanced Nanomaterials, Nanotech for Energy and Environment, Nano Computational Modelling, Nano Materials Synthesis and Characterisation, Nanobiomaterials, Molecular Mimics, Nanotechnology Safety, Nanophotonics, Nanotechnology and Cosmetics, Nanotechnology in Tissue Engineering, Nanotechnology in Agriculture and Food Industry,

As the characteristic dimensions of electronic devices continue to shrink, the ability to characterize their electronic properties at the nanometer scale has come to be of outstanding importance. In this sense, Scanning Probe Microscopy (SPM) is becoming an indispensable tool, playing a key role in nanoscience and nanotechnology. SPM is opening new opportunities to measure semiconductor electronic properties with unprecedented spatial resolution. SPM is being successfully applied for nanoscale characterization of ferroelectric thin films. In the area of functional molecular materials it is being used as a probe to contact molecular structures in order to characterize their electrical properties, as a manipulator to assemble nanoparticles and nanotubes into simple devices, and as a tool to pattern molecular nanostructures. This book provides in-depth information on new and emerging applications of SPM to the field of materials science, namely in the areas of characterisation, device application and nanofabrication of functional materials. Starting with the general properties of functional materials the authors present an updated overview of the fundamentals of Scanning Probe Techniques and the application of SPM techniques to the characterization of specified functional materials such as piezoelectric and ferroelectric and to the fabrication of some nano electronic devices. Its uniqueness is in the combination of the fundamental nanoscale research with the progress in fabrication of realistic nanodevices. By bringing together the contribution of leading researchers from the materials science and SPM communities, relevant information is conveyed that allows researchers to learn more about the actual developments in SPM applied to functional materials. This book will contribute to the continuous education and development in the field of nanotechnology.

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.