Ink-jet printed thin-film transistors with carbon nanotube channels shaped in long strips

The present work reports on the development of a class of sophisticated thin-film transistors (TFTs) based on ink-jet printing of pristine single-walled carbon nanotubes (SWCNTs) for the channel formation. The transistors are manufactured on oxidized silicon wafers and flexible plastic substrates at ambient conditions. For this purpose, ink-jet printing techniques are developed with the aim of high-throughput production of SWCNT thin-film channels shaped in long strips. Stable SWCNT inks with proper fluidic characteristics are formulated by polymer addition. The present work unveils, through Monte Carlo simulations and in light of heterogeneous percolation, the underlying physics of the superiority of long-strip channels for SWCNT TFTs. It further predicts the compatibility of such a channel structure with ink-jet printing, taking into account the minimum dimensions achievable by commercially available printers. The printed devices exhibit improved electrical performance and scalability as compared to previously reported ink-jet printed SWCNT TFTs. The present work demonstrates that ink-jet printed SWCNT TFTs of long-strip channels are promising building blocks for flexible electronics. (C) 2011 American Institute of Physics. [doi:10.1063/1.3569842]