Abstract
Abstract The works presented in this thesis discuss the effects of non-covalent interaction with carbon nanotubes and molecules as well as Boron-dopants modify electronic structure of carbon nanotubes. Surface decoration has been proved to be important in changing the physico-chemical properties of nanotubes. For example, surface tension, gas sensing and purification via surface reaction are discussed in this study. Doping is well known effective in changing electrical properties of Si-based devices, and it also works in carbon nanotubes. In this study, we demonstrate how bending effect electrical properties in Boron-doped carbon nanotubes (BCNTs) and single-walled carbon nanotubes (SWCNTs). Chapter 1 introduces the basic concept of nanotubes surface decoration by different molecules, e.g. polymers, surfactants, and others chemical species. Two attachments will be discussed, inside and outside the tube, along with the influence of infrared spectroscope analyses. Chapter 2 will discuss the experimental methods, and characterization techniques employed in this study. Chapter 3 shows the ammonia blast on nanotube surface. This work demonstrates the removal of carbonaceous impurities and catalytic particles from carbon nanotube surfaces by ammonia explosion and data reveals that gas sensitivity of purified nanotubes becomes faster by a factor of 3.8 compared with pristine materials. Chapter 4 discusses the observations of surface tension change upon NH3 attachment and droplet (deionized water) migration on nanotube surface. Droplet moving rate, surface tensions of pristine and decorated nanotube films are calculated from experiment information. Feasible mechanism is proposed and influence of droplet migration by external magnetic field is also predicted. Chapter 5 mainly focuses on electron tunneling through boron doped carbon nanotubes. We also show the difference electronic behavior between undoped and B-doped nanotubes. In this chapter, we describe the phenomenon of nanotube deflection driven electron transmission. Chapter 6 concludes results of our experiments.