Fabrication and characterization of field-effect transistor device with C_2v isomer of Pr@C₈₂

A field-effect transistor (FET) device was fabricated with thin films of C_2v isomer of Pr@C₈₂. This device apparently showed n-channel normally-on type FET properties, where non-zero current was observed at gate-source voltage of 0 V_GS, of 0V. Normally off FET properties were observed by subtraction of the non-zero current from the drain current.Thus the normally on properties are ascribed to the high bulk current caused by the small energy gap ≈0.3 eV. The field-effect mobility for this FET was 1.5 x 10^-4 cm² V^-1 s^-1 at 320 K, being comparable to those of other endohedral metallofullerene FET devices.