High-mobility carbon-nanotube thin-film transistors on a polymeric substrate

We report the development of high-mobility carbon-nanotube thin-film transistors fabricated on a polymeric substrate. The active semiconducting channel in the devices is composed of a random two-dimensional network of single-walled carbon nanotubes (SWNTs). The devices exhibit a field-effect mobility of 150 cm(2)/Vs and a normalized transconductance of 0.5 mS/mm. The ratio of on-current (I-on) to off-current (I-off) is similar to100 and is limited by metallic SWNTs in the network. With electronic purification of the SWNTs and improved gate capacitance we project that the transconductance can be increased to similar to10-100 mS/mm with a significantly higher value of I-on/I-off, thus approaching crystalline semiconductor-like performance on polymeric substrates. (C) 2005 American Institute of Physics.