Professor Sang Ouk Kim from the KAIST Department of Materials Science and Engineering has published a paper titled “Chemically Modified/Doped Carbon Nanotubes & Graphene for Optimized Nanostructures & Nanodevices” as an invited special review article for the 25th anniversary of the journal Advanced Materials. Throughout the paper, he reviews the current progress on chemical modification and doping methods, and the relevant applications of carbon nanotubes (CNT) and graphene. In commemoration of the journal’s 25th anniversary, the editors had selected leading researchers in the field through a rigorous review process to have their works introduced in the issue.

Chemical doping is the process of introducing foreign elements to a pure substance to enhance desirable physical or chemical properties. Conventional silicon based semiconductors also make use of chemical doping to achieve the desired properties. While new materials such as CNTs and graphene have outstanding properties in their pure form, doping with various other elements is still necessary for industrial application. Doping can enhance properties such as conductivity and reactivity to overcome low solution dispersion, which has been a bottleneck in their industrial application.

A crucial criterion for cost effective processing, solution dispersibility of CNTs and graphene can be induced by wet chemical or dry oxidation processes. Liquid crystallinity can be induced, which is greatly favorable for  the formation of highly ordered structures in fibers and nano-composites. Chemically doped graphene with modified surface energy can be used as a flexible substrate for nanopatterning and direct nanostructure fabrication onto flexible geometry due to its high thermal and chemical stability, which has been difficult to achieve with conventional polymer based flexible substrates.