Electrochemical carbon nanotube field-effect transistor

We explore the electric-field effect of carbon nanotubes (NTs) in electrolytes. Due to the large gate capacitance, Fermi energy ${\mathrm{(E}}_F)$ shifts of order ±1 V can be induced, enabling to tune NTs from p to n-type. Consequently, large resistance changes are measured. At zero gate voltage, the NTs are hole-doped in air with ${\mathrm{|E}}_F\text{|≈0.3–0.5\hspace{0.05em}}\mathrm{eV},$ corresponding to a doping level of ${\text{≈10}}^{13} {\mathrm{cm}}^{\mathrm{-2}}.$ Hole-doping increases in the electrolyte.