Sökning: "Nanoribbons"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet Nanoribbons.

1. 1. Quantum Transport Theory in Graphene

   Författare :Anders Bergvall; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum coherent electron transport; nanoribbons; FT-LDOS; grain boundaries; tight-binding; graphene;

   Sammanfattning : In this thesis, we focus on different aspects of electron transport in nanostructured graphene (such as graphene nanoribbons). Wedevelop and implement numerical methods to study quantum coherent electron transport on an atomistic level, complemented by analytical calculations based on the Dirac approximation valid close to the points $\vec{K}$ and $\vec{K}^\prime$ in the graphene Brillouin zone. LÄS MER

3. 2. Materials for Hydrogen storage and synthesis of new materials by hydrogenation

   Författare :Serhiy Luzan; Alexandr Talyzin; Yaroslav Filinchuk; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fullerene C60; MOFs; CNTs; SWCNTs; PAHs; peapods; hydrogen; hydrogen storage; hydrogenation; adsorption; surface area; pore volume; spillover; nanoribbons; fragmentation; fysikalisk kemi; Physical Chemistry; fysik; Physics;

   Sammanfattning : The search for new materials for hydrogen storage is important for the development of future hydrogen energy applications. In this Thesis, it is shown that new materials with interesting properties can be synthesized by the reaction of hydrogen with various nanocarbon precursors. The thesis consists of two parts. LÄS MER

4. 3. First Principles Studies of Functional Materials Based on Graphene and Organometallics

   Författare :Sumanta Bhandary; Biplab Sanyal; Olle Eriksson; Stefano Sanvito; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Graphene; Magnetism; Organometallics; Density functional theory; Electron correlation; Spin switching; Nanoribbons; Exchange interaction; Edge functionalization; Band gap; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Graphene is foreseen to be the basis of future electronics owing to its ultra thin structure, extremely high charge carrier mobility,  high thermal conductivity etc., which are expected to overcome the size limitation and heat dissipation problem in silicon based transistors. LÄS MER

5. 4. Charge-Spin Conversion and Electronic Transport in Two-Dimensional Materials and van der Waals Heterostructures

   Författare :Anamul Md Hoque; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Spin-orbit coupling; Nanoribbons; Nanotransistor; Graphene; Chemical vapor deposition; Spintronics; Charge-spin conversion; Two-dimensional materials; Proximity effect; van der Waals heterostructure;

   Sammanfattning : Applications related to artificial intelligence (AI), 5G communication, cloud computing, Internet of Things (IoT) will necessitate wide range of data collection, communication and processing. Current charge-based technology using conventional materials suffers adverse effects with down-scaling the device size and has limited efficiency in meeting the future demands for computation and data storage. LÄS MER

7. 5. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

   Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER