[Thu. 1 Dec. 2016] Prof. Sang-Yong Ju/Highly Pure Carbon Nanotubes sorted by a Flavin for Thin Film Transistor Applications

“Highly Pure Carbon Nanotubes sorted by a Flavin
for Thin Film Transistor Applications”
  

Scalable and simple methods for selective extraction of pure, semiconducting (s) single-walled carbon nanotubes (SWNTs) is of profound importance for electronic and photovoltaic applications. In this seminar, I report a new, one-step procedure to obtain respective large-diameter s- and metallic (m)-SWNTs enrichment purity in excess of 99% and 78%, respectively, via interaction between aromatic dispersing agent and SWNTs. The approach utilizes N-dodecyl isoalloxazine (FC12) as a surfactant in conjunction with sonication and bench top centrifugation methods. After centrifugation, the supernatant is enriched in s-SWNTs0 with less carbonaceous impurities whereas precipitate is enhanced in m-SWNTs. In addition, the use of an increased centrifugal force enhances both the purity and population of larger diameter s-SWNTs. Photo-induced energy transfer from FC12 to SWNTs is facilitated by respective electronic level alignment. Owing to its peculiar photoreduction capability, FC12 can be employed to precipitate SWNTs upon UV irradiation and observe absorption of higher optical transitions of SWNTs. A thin film transistor prepared from a dispersion of enriched s-SWNTs was fabricated to verify electrical performance of the sorted sample, and was observed to display p-type conductance with an average on/off ratio over 106 and an average mobility over 10 cm2/V∙s.

Prof. Sang-Yong Ju
Department of Chemistry, Yonsei University, South Korea