Thin-Film Transistors Using Uniform and Well-Aligned Single-Walled Carbon Nanotubes Channels by Dielectrophoretic Assembly

Abstract

A single-walled carbon nanotube thin-film transistor (SWCNT TFT) was formed by an aligned SWCNTs channel assembled by the dielectrophoretic (DEP) process. In this work, we investigated the effects of the DEP factors (frequency, solution concentration) on structural (orientation and density in the SWCNT channels) and electrical properties of SWCNT TFTs. A uniform, well-aligned and density controlled SWCNT channel was achieved by optimizing the DEP assembly process, and as a result, electrical properties (mobility and on/off current ratio) of SWCNT TFTs were improved. In addition, we also discussed the effect of uniformity of assembled SWNTs in a channel on performance variation of the SWCNT TFTs. We found that the tube density and uniformity are key parameters which determine electrical properties and performance variation of SWCNT TFTs.