Eletronic properties in nanosystems based on carbono nanotubes and graphene

Author(s)

Alexsandro Kirch

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2014-03-13

Examining board members

Adalberto Fazzio; Noelio Oliveira Dantas; Armando Corbani Ferraz

• Advisor: Adalberto Fazzio

Abstract

In this work, ab initio calculations were performed within DFT framework to analyse electronic properties of Carbon nanotubes and grapheme nano systems. In this work, computer simulations were performed to investigate the electronic properties of nanosystems based on carbon nanotubes and graphene within DFT framework. One of these systems studied is a Carbon nanotube semiconductor coupled to encapsulated leads of Pd nanowires. It has been shown that leads states interact strongly with the carbon nanotube states. Electronic transport calculations were performed to unfold new applications of this system, such as the field effect transistor. We noticed that charge current intensity can be tuned by electrical field. We also described the influence of amorphous SiO2 and h-BN, in H2 energy adsorption and charge transfer, where both materials are used as graphene substrates. It was shown that the latter adsorption energy in the graphene/Si02 is smaller than graphene/h-Bn and the graphene suspended itself. In fact this adsorption results in a charge transference one order greater than in the suspended graphene, which can be seen as a vertical shift of the Dirac Cone. This study may improve the construction of future H2 sensors based on graphene. (AU)

• FAPESP's process: 12/12242-6 - Graphene with adsorbed molecules: transport properties in radio frequency transistors and sensors
• Grantee: Alexsandro Kirch
• Support Opportunities: Scholarships in Brazil - Master