N-type and p-type double-walled carbon nanotube field-effect transistors based on charge-transfer modulation

Abstract

Electrical transport properties of double-walled carbon nanotubes (DWNTs) are modulated by encapsulating alkali-metal Cs atom or C60 molecules via a plasma ion-irradiation method. The pristine DWNTs are found to exhibit ambipolar semiconducting behavior due to their small bandgap. In contrast, Cs and C60 encapsulated DWNTs exhibit high performance unipolar n-type and p-type semiconducting behavior since they can operate as an electron donor and acceptor, respectively. Moreover, by controlling the filling level, p–n junction is found to be formed in DWNTs by Cs encapsulation. Our results indicate that DWNTs have great potential as building blocks for various electronic nano devices.