Field-effect transistor made of individual V2O5 nanofibers

A field-effect transistor (FET) with a channel length of $\text{∼100\hspace{0.05em}}\mathrm{nm}$ was constructed from a small number of individual ${\mathrm{V}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{5}}$ fibers of the cross section $\text{1.5\hspace{0.05em}}\mathrm{nm\times 10 nm}.$ 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 ${\text{7.7×10}}^{\text{−5}} {\mathrm{cm}}^{\mathrm{2}}\mathrm{/V s}$ at $\text{T=131\hspace{0.05em}}\mathrm{K}$ to ${\text{9.6×10}}^{\text{−3}} {\mathrm{cm}}^{\mathrm{2}}\mathrm{/V s}$ at $\text{T=192\hspace{0.05em}}\mathrm{K}$ with an activation energy of $E_a\text{=0.18\hspace{0.05em}}\mathrm{eV}.$ 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 $\text{∼4\hspace{0.05em}}\mathrm{nm}.$