Fabrication and characteristics of C84 fullerene field-effect transistors

Fullerene field-effect transistors (FETs) were fabricated with thin films of ${\mathrm{C}}_{84},$ which showed $n$ -channel normally-on depletion-type FET characteristics. The ${\mathrm{C}}_{84}$ FET device exhibited the highest mobility, μ, of ${\text{2.1×10}}^{\text{−3}}\hspace{0.17em}{\mathrm{cm}}^2 {\mathrm{V}}^{\text{−1}} {\mathrm{s}}^{\text{−1}}$ among normally-on fullerene FETs. The carrier transport of this FET device can be interpreted as thermally activated hopping transport. Carrier type $\mathrm{(n}$ -channel) and transport mechanism (hopping) reflect the electronic properties of the ${\mathrm{C}}_{84}$ molecule.