Electronic-structure engineering of carbon nanotubes

A review for controlling electronic structures and chirality separation of carbon nanotubes (CNTs) is presented with the subject divided into three topics. The first topic introduces the electronic structures of CNTs and the analytical techniques to identify the chirality of CNTs. The second topic discusses band gap engineering techniques using the sidewall functionalization of CNTs. The third topic concerns several approaches in chiral and diameter-dependent separation of CNTs. The electronic-structure engineering is of critical importance for a variety of technological applications of CNTs including, for example, field-effect transistor, chemical/bionanosensors, the electrical conductivity and charge dissipation in polymer/CNT composites, and flexible transparent conducting films. This paper is intended to concisely review the recent advances in the experimental and theoretical CNT researches concerned with the band gap engineering and chiral separation techniques of CNTs.