ABSTRACT
A single-wall carbon nanotube (SWCNT) can be viewed as a single layer of graphite (graphene) rolled up into a seamless cylinder. Differentiated by the direction of rolling up, an SWCNT can be a semiconducting SWCNT (s-SWCNT) or a metallic SWCNT (m-SWCNT). An S-SWCNT is a type of semiconducting material with bandgap inversely proportional to its diameter, whereas an m-SWCNT is generally considered a metallic wire. SWCNTs have attracted a lot of attention because of their simple structures and easily predictable electronic properties. The diameter-dependent energy gap makes s-SWCNTs attractive for various nanoelectronic devices. SWCNT based field-effect transistors (FETs) have the simplest geometry that consists of two metal electrodes connected by an s-SWCNT on the top of a conducting substrate capped by an insulating layer. Due to one-dimensional (1-D) nature of s-SWCNT, electron transport in the 1-D nanostructure is confined so that s-SWCNTs have an inherent advantage over bulk semiconducting materials to work as the key
component in a single-electron transistor (SET). As SWCNTs have a very large surface-to-volume ratio, the conductance in SWCNTs is very sensitive to the electrostatic environment around the SWCNTs. The high sensitivity makes the s-SWCNT a perfect candidate for memory application. Because of these unique electronic properties, SWCNTs have been studied intensively in the past decade. The state-of-the-art electronic applications of the SWCNTs have been explored. In this chapter, we review the roles of SWCNTs in various types of semiconducting devices, such as FETs, SETs, and FET-and SET-based logic circuits, and memory devices.
