Field-effect transistor made of individual V2O5 nanofibers

A field-effect transistor (FET) with a channel length of ∼100 nm was constructed from a small number of individual V2O5 fibers of the cross section 1.5 nm×10 nm. At low temperature, the conductance increases as the gate voltage is changed from negative to positive values, characteristic of a FET with n-type enhancement mode. The carrier mobility, estimated from the low-field regime, is found to increase from 7.7×10−5 cm2/V s at T=131 K to 9.6×10−3 cm2/V s at T=192 K with an activation energy of Ea=0.18 eV. The nonohmic current/voltage dependence at high electric fields was analyzed in the frame of small polaron hopping conduction, yielding a nearest-neighbor hopping distance of ∼4 nm.