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Full-Text Articles in Nanoscience and Nanotechnology
Electron Transport In One And Two Dimensional Materials, Samuel William Lagasse
Electron Transport In One And Two Dimensional Materials, Samuel William Lagasse
Legacy Theses & Dissertations (2009 - 2024)
This dissertation presents theoretical and experimental studies in carbon nanotubes (CNTs), graphene, and van der Waals heterostructures. The first half of the dissertation focuses on cutting edge tight-binding-based quantum transport models which are used to study proton irradiation-induced single-event effects in carbon nanotubes [1], total ionizing dose effects in graphene [2], quantum hall effect in graded graphene p-n junctions [3], and ballistic electron focusing in graphene p-n junctions [4]. In each study, tight-binding models are developed, with heavy emphasis on tying to experimental data. Once benchmarked against experiment, properties of each system which are difficult to access in the laboratory, …
Tetradymite Topological Insulators : Towards High Performance Broadband Photodetection, Asish Parbatani
Tetradymite Topological Insulators : Towards High Performance Broadband Photodetection, Asish Parbatani
Legacy Theses & Dissertations (2009 - 2024)
Topological insulators are characterized by the presence of a finite energy gap in the bulk state and a conducting metallic surface state consisting of odd number of Dirac cones. The conducting surface states are along the edge boundaries, free from disorders and are protected by time reversal symmetry. The presence of Dirac cone leads to universal optical absorption phenomenon like graphene. This phenomenon of universal optical absorption leads to frequency independent photoexcitation of carriers. Bi2Te3, Sb2Te3 and Bi2Se3 belong to tetradymite topological insulators (TTI) family and are often referred to as 3D layered materials. Theoretical predictions characterize TTIs by low …
Growth Of Epitaxial Graphene On Single Crystal Copper Surfaces By Chemical Vapor Deposition, Tyler Rutley Mowll
Growth Of Epitaxial Graphene On Single Crystal Copper Surfaces By Chemical Vapor Deposition, Tyler Rutley Mowll
Legacy Theses & Dissertations (2009 - 2024)
Graphene is of significant interest due to its unique properties, such as high carrier mobility, mechanical strength, and thermal conductivity. Potential applications include next generation transistors, interconnects, biological and chemical sensing devices, and super capacitors. The research presented here addresses unresolved questions regarding the nucleation and growth of graphene by chemical vapor deposition (CVD) on the high index surfaces of copper single crystals. While much CVD graphene growth has been performed on copper foils, the polycrystalline nature of the foils renders large-scale single domain growth of graphene difficult. For this reason, many groups seek to reduce the nucleation rate of …
Graphene’S Electronic Surface States On Metal Substrates, Alex De Palma
Graphene’S Electronic Surface States On Metal Substrates, Alex De Palma
Nanoscale Science & Engineering (discontinued with class year 2014)
Graphene is a 2-‐D sheet of sp2 bonded carbon atoms with exceptional electrical properties. Particularly, graphene has a very high carrier mobility (~200,000 cm2/V·∙s). This is largely due to graphene’s unique electronic structure, wherein charge carriers are effectively massless Dirac fermions. However, the unique electronic structure of graphene has been shown to be affected by the underlying substrate. In this study, we characterize the electronic structure of graphene on copper. Electron energy loss spectroscopy is employed to observe the surface plasmon excitations of graphene. A small pi plasmon excitation is observed, suggesting that the graphene/Cu interaction is weak and non-‐covalent. …
Carbon 1d/2d Nanoelectronics : Integration And Device Applications, Zhaoying Hu
Carbon 1d/2d Nanoelectronics : Integration And Device Applications, Zhaoying Hu
Legacy Theses & Dissertations (2009 - 2024)
Graphene is a one-atom thick planar monolayer of sp2-bonded carbon atoms organized in a hexagonal crystal lattice. A single walled carbon nanotube (CNT) can be thought of as a graphene sheet rolled up into a seamless hollow cylinder with extremely high length-to-diameter ratio. Their ultra-thin body, large surface area, and exceptional electronic, optical and mechanical properties make these low-dimensional carbon materials ideal candidates for electronic applications. However, adopting low-dimensional carbon materials into semiconductor industry faces significant material and integration challenges. There is an urgent need for research at fundamental and applicative levels to find a roadmap for carbon nanomaterial to …
Hexagonal Boron Nitride : Ubiquitous Layered Dielectric For Two-Dimensional Electronics, Nikhil Jain
Hexagonal Boron Nitride : Ubiquitous Layered Dielectric For Two-Dimensional Electronics, Nikhil Jain
Legacy Theses & Dissertations (2009 - 2024)
Hexagonal boron nitride (h-BN), a layer-structured dielectric with very similar crystalline lattice to that of graphene, has been studied as a ubiquitous dielectric for two-dimensional electronics. While 2D materials may lead to future platform for electronics, traditional thin-film dielectrics (e.g., various oxides) make highly invasive interface with graphene. Multiple key roles of h-BN in graphene electronics are explored in this thesis. 2D graphene/h-BN heterostructures are designed and implemented in diverse configurations in which h-BN is evaluated as a supporting substrate, a gate dielectric, a passivation layer, or an interposing barrier in “3D graphene” superlattice. First, CVD-grown graphene on h-BN substrate …
Fundamental Studies Of Supported Graphene Interfaces : Defect Density Of States In Graphene Field Effect Transistors (Fets) And Ideal Graphene - Silicon Schottky Diodes, Dhiraj Sinha
Legacy Theses & Dissertations (2009 - 2024)
The physics of transport in atomically thin 2D materials is an active area of research, important for understanding fundamental properties of reduced dimensional materials and for applications. New phenomena based on graphene may include properties of topologically protected insulators. Applications of these materials are envisioned in electronics, optoelectronics and spintronics.
Growth And Characterization Of Graphene On Cuni Substrates, Parul Tyagi
Growth And Characterization Of Graphene On Cuni Substrates, Parul Tyagi
Legacy Theses & Dissertations (2009 - 2024)
Graphene is a single layer of sp2 bonded carbon atoms that crystallizes in the honeycomb structure. Because of its true two-dimensional structure, it has very unique electrical properties, including a very high carrier mobility that is symmetric for holes and electrons. To realize these unique properties, it is important to develop a method for growing graphene films with uniform thickness and low defect density. One of the most popular methods of growth is by chemical vapor deposition on Cu substrates, because it is self-limited. However many applications require the growth of graphene films that are more than one atomic layer …
Measurement Of Electron Spin Transport In Graphene On 6h-Silicon Carbide(0001), Joseph Abel
Measurement Of Electron Spin Transport In Graphene On 6h-Silicon Carbide(0001), Joseph Abel
Legacy Theses & Dissertations (2009 - 2024)
The focus of this thesis is to demonstrate the potential of wafer scale graphene spintronics. Graphene is a single atomic layer of sp2-bonded carbon atoms that has high carrier mobilities, making it a desirable material for future nanoscale electronic devices. The vision of spintronics is to utilize the spin of the electron to produce novel high-speed low power consuming devices. Materials with long spin relaxation times and spin diffusion lengths are needed to realize these goals. Graphene is an ideal material as it meets these requirements and is amenable to planar device geometries.
Study Of The Dielectric Function Of Graphene From Spectroscopic Ellipsometry And Electron Energy Loss Spectroscopy, Florence Joan Nelson
Study Of The Dielectric Function Of Graphene From Spectroscopic Ellipsometry And Electron Energy Loss Spectroscopy, Florence Joan Nelson
Legacy Theses & Dissertations (2009 - 2024)
For more than 60 years, semiconductor research has been advancing up the periodic table. The first transistor was made from germanium. This later gave way to silicon-based devices due to the latter's ability to form an excellent interface with thermally-grown oxide. Now for the last ~8 years, the focus has moved up one more row to carbon for post-CMOS devices in order to comply with the scaling limitations of Moore's law. However, for each of these, the measurements of film properties and dimensions have always been required for technological applications. These measurement methods often incorporate the use of light or …
The Influence Of Copper Substrate Orientation On Graphene Growth, Zachary Robert Robinson
The Influence Of Copper Substrate Orientation On Graphene Growth, Zachary Robert Robinson
Legacy Theses & Dissertations (2009 - 2024)
This dissertation is focused on determining the influence of the copper substrate on graphene grown by \ac{CVD}. Graphene, which can be grown in single atomic layers on copper substrates, has potential applications in future electronic devices. One of the key issues for the use of graphene grown by chemical vapor deposition for device applications is the influence of defects on the transport properties of the graphene. For instance, growth on metal foil substrates results in multi-domain graphene growth because the foil substrates themselves have a variety of different surface terminations. Therefore, they don't serve as a very good template for …
Graphene-Based Post-Cmos Architecture, Sansiri Tanachutiwat
Graphene-Based Post-Cmos Architecture, Sansiri Tanachutiwat
Legacy Theses & Dissertations (2009 - 2024)
The semiconductor industry relies on CMOS technology which is nearing its scaling limitations. In order to continue the historical growth rate of the device density of digital logic chips, novel nanomaterials and nanodevices will need to be developed.
Graphene-Based Interconnects : Electrical Performance And Reliability, Tianhua Yu
Graphene-Based Interconnects : Electrical Performance And Reliability, Tianhua Yu
Legacy Theses & Dissertations (2009 - 2024)
According to the ITRS Roadmap, on-chip interconnects wire width and current density will reach 22 nm and 5.8×106 A/cm2 in 2020, respectively. The electrical resistivity of Cu increases with scaled critical dimensions due to exacerbated carrier scattering at grain boundaries and interfaces, resulting in signal speed degradation. Electronmigration (EM)-related failure due to intensified current distribution posts extra limits to ultra-scaled systems. Innovative interconnect solutions are needed to tackle performance and scaling challenges.
Effects Of Low Energy E-Beam Irradiation On Graphene And Graphene Field Effect Transistors And Raman Metrology Of Graphene On Split Gate Test Structures, Gayathri Rao
Legacy Theses & Dissertations (2009 - 2024)
Apart from its compelling performance in conventional nanoelectronic device geometries, graphene is an appropriate candidate to study certain interesting phenomenon (e.g. the Veselago lens effect) predicted on the basis of its linear electron dispersion relation. A key requirement for the observation of such phenomenon in graphene and for its use in conventional field-effect transistor (FET) devices is the need to minimize defects such as consisting of - or resulting from - adsorbates and lattice non-uniformities, and reduce deleterious substrate effects. Consequently the investigation of the origin and interaction of defects in the graphene lattice is essential to improve and tailor …