Chemical Engineering of Graphene and Single-Walled Carbon Nanotubes for Electronic Applications

Carbon nanomaterials have received a great deal of attention and investment in recent years, not only because of their excellent properties, but also driven by the fact that conventional Si-based electronics is pushed to its limits, and when the size of a Si based transistor is miniaturized to several nanometers, the cost increases dramatically. Chapter 1 reviews the synthesis, properties and application of carbon nanotubes and graphene. Chemical functionalization is an efficient way to manipulate and tune the properties of carbon nanomaterials and to broaden their applications in different fields. Transfer of CVD transfer without degrading its quality is essential to the wide applications of this carbon material in electronics. In Chapter 2, two novel graphene transfer methods are reported. The availability of clean graphene is critical for the chemical modification of graphene and its application in flexible electronics. The interaction between carbon surfaces and transition metals, discussed in Chapter 3, has long been an interesting topic. Graphene half sandwich complexes and graphene sandwich complexes were successfully synthesized and the electrical conductivity was used to characterize the synthetic process. Besides, the fascinating electrical properties of individual carbon nanotubes were extended toward macroscale by aligning individual tubes on a large scale and applying organometallic chemistry to constructively interconnect the sidewalls of parallel tubes and two ends of nanotubes in series with transition metals, which greatly improved the electrical performance of aligned carbon nanotube devices and paves the way for the fabrication of carbon nanotube-based high performance microprocessors. The absence of a bandgap in graphene inhibits its application to transistors, meanwhile from a chemical standpoint the unique band structure of graphene dictates the chemical reactivity of graphene as exemplified in the Diels Alder (DA) reaction discussed in Chapter 4. The effect of a facile room temperature DA reaction on the magnetoresistance of epitaxial graphene (Epigraphene) was studied in a temperature range from 300 K to 2 K. The transition from the positive magnetoresistance in pristine Epigraphene to a large negative magnetoresistance in naphthazarin-Epigrahene adduct provides an alternative way to develop graphene based magneto-electronic devices