Enhancement of carbon nanotube FET performance via direct synthesis of poly (sodium 4-styrenesulfonate) in the transistor channel

Direct synthesis of poly (sodium 4-styrenesulfonate) (P(NaSS)) inside the channel of single-walled carbon nanotube (SWCNT) field-effect transistors (FETs), is shown to be highly beneficial in improving the device parameters. Starting with monomeric compounds, the FET-channel was in-situ polymerized, using the self-initiated photografting and photopolymerization process. Upon formation of the P(NaSS) polymer matrix, we report improved device-to-device consistency, lower variability in the threshold voltage, higher drain currents and higher on/off ratios. Annealing in vacuum was shown to further improve the device performance and induce an ambipolar behavior. Moreover, those FET devices showed a long-term stability even under ambient environment.