Estimation of Demand on Freeway Rest Area using Drivers travel time

학위논문(석사) --서울대학교 환경대학원 :환경계획학과(교통관리전공),2010.2.Maste

Single Walled Carbon Nanotube Schottky Diode via Selective Electrochemical Metal Deposition

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Carbon Nanotubes Schottky Diode from Asymmetric Carbon Nanotubes-

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The Studies of Functional Surface Chemistry on Fullerene, Carbon Nanotube and Graphene: Development, Characterization and Application

DoctorBefore discovery of fullerene, graphite and diamond are only regarded as carbon allotropes. Since fullerene was discovered, carbon nanotube and graphene were discovered, which demonstrate the existence of new carbon nano-allotropes. According to their dimensions (fullerene : 0D, carbon nanotube : 1D and graphene 2D), they have unique optical and electric properties. Hence, they have been interested as building blocks for various applications. In order to improve their qualities and modify the properties, many chemists have studied to develop functional surface chemistry on carbon nanostructure. In this thesis, our approaches to develop new functional surface reactions are discussed. In section one, I provide the general introduction of fullerene, carbon nanotube and graphene briefly, to help readers understand this thesis. It includes the history, synthetic methods, electronic structures, electrical properties and phonon behaviors for fullerene, carbon nanotube and graphene, respectively. In section two, the reaction for conversion of single-crystalline C60 nanostructures into graphitic nanostructure via hydrogen annealing is discussed. We demonstrated the coalescence reaction by simple hydrogen annealing is occurred in C60 nanocrystals, which results porous graphitic structures. This investigation may open a new way to attain diverse graphitic nanostructures economically, and we suggest that resulted porous graphitic structures can be useful for energy storage such as hydrogen and lithium ions because they have extremely large surface area. In section three, new facile methods to realized SWNT-based diodes are discussed. Although diode is one of important building blocks for integrated circuits, the methods to realize that are very difficult since SWNTs generally show only p-type semiconducting properties. In order to resolve the problem, we developed the new simple method to fabricate SWNT Schottky diodes to control the movement of metal cations. First, lithium intercalation reaction into pyrene-functionalized SWNT was demonstrated and then mass transport of lithium ions was controlled to one-side electrode. This induced asymmetric Schottky contacts in SWNT devices. As a result, SWNT-Schottky diode could be realized. The second method is the selective electrochemical plating on one-side electrode. Although the main concept is similar, the resulted devices showed higher on-state conductance. In section four, fundamental studies for chemical reactivity and interaction with substrate of graphene are discussed. Because the history of graphene is the shortest among carbon nanostructures (fullerene, carbon nanotube and graphene), fundamental studies to characterize its properties are still required. We demonstrate the spatially resolved reactivity on edge and basal plane of single-layer graphene and the method to confirm the non-covalent doping effect by Raman spectroscopy. Additionally, we observed anomalously large surface charge trap in single-layer graphene sheet on SiO2 layers. We suggest that this phenomenon corresponds with the factors to restrict the performance of graphene devices

The Spatially Resolved Spontaneous Reactivity of Diazonium Salt on Edge and Center of Graphene and Its Doping Effect”

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Conversion of single crystalline C60 nanostructures into graphitic nanostructures via hydrogen thermal annealing

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Carbon nanotube schottky diode from asymmetric electrode by mass transport of Li ions

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Carbon nanotube Schottky diode from asymmetric carbon nanotube-metal junctions induced by mass trasnport of lithium ions

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Mass Transport of Lithium Ions Intercalated in Pyrene-functionalized Single-Walled Carbon Nanotubes: Afacile Way to Schottky Diode

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Hydrosilylation on single walled carbon nanotubes (SWNTs): Conversion of metallic SWNTs to semiconducting SWNTs

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