Piperidine induced polarity conversion in single-walled carbon nanotube field effect transistors

Piperidine is found to be an efficient electron doping agent that converts as-prepared p-type single-walled carbon nanotube (SWCNT) field effect transistors (FETs) into n-type SWCNT-FETs. Electron transfer from the amine group in piperidine to the SWCNTs is suggested to be the origin of the p-to n-type conversion. The effect of electron doping is further supported by the Raman tangential G⁺ and G^--peak downshift up to 3cm ^{- 1} without the peak broadening. No detectable change in the Raman D-peak suggests non-covalent attachment of piperidine to the SWCNTs. A low temperature (110 °C) Si₃N₄ passivation layer is used to maintain the long term air stability of the converted n-type devices. A complementary SWCNT inverter is demonstrated through integrating the n-and p-type SWCNT-FETs.