Sorting Semiconducting Single-Walled Carbon Nanotubes and Using Them as Random Network of Field-Effect Transistors

Abstract

Single-walled carbon nanotubes (SWCNTs) with incovalently attached iodine, were obtained by physical absorption. The di®erent diameter sizes of SWCNTs, with di®erent numbers of iodine molecule, enhance the density contrast between them which becomes evident in density gradient ultracentrifugation (DGU) targeted to sort certain species of SWCNTs. The results of optical absorbance and photoluminescence emission showed that iodine-assisted DGU preferentially separates semiconducting nanotubes with certain diameters [(6, 5), (7, 5), (8, 4), and (7, 6)].We have applied these semiconducting, species enriched SWCNTs to prepare solution-processed¯eld e®ect transistor (FET) devices with random nanotube network active channels. The devices exhibit stable p-type semiconductor behavior in air with very promising characteristics. The ono® current ratio reaches up to 2 Â 10 4 within a narrow window of voltage (À10 V to 10 V), and estimated hole mobility of 21.7 cm 2 V À1 s À1 .

Exploring the alignment of carbon nanotubes dispersed in a liquid crystal matrix using coplanar electrodes

“…This has led to significant scientific and technological activities in their exploitation. Examples of possible applications include chemical sensors, 1,2 carbon nanotube field-effect transistors, [3][4][5] active matrix organic light-emitting devices 6 and, most recently, evolvable computation. 7 For the latter application, external stimuli (e.g., electric fields) are applied to alter the behavior of a material system (evolution-in-materio).…”