Influence of temperature on high frequency performance of graphene nano ribbon field effect transistor

We have fabricated an original graphene field effect transistor (FET) on silicon carbide (SiC) substrate. Based on an array of parallel graphene nano ribbons (GNRs), these devices are well suited for high frequency (HF) applications. Exploration of HF performance shows at room temperature intrinsic current gain cut-off frequency if) of 10 GHz and maximum oscillation frequency (f_max) of 6 GHz. At 77 K, we find out that these HF performance are improved by about 50% (f_t and f_max are respectively 15 GHz and 10 GHz). These results show the strong dependence of temperature on device performance.