▎ 摘　　要

Flexible graphene field effect transistors (GFETs) are fabricated on a polyimide (PI) substrate by an improved self-aligned fabrication procedure. Short gate length of 50nm is achieved. Ohmic contact resistance is depressed. The prepared GFET shows comparable intrinsic cut-off frequency and maximum oscillation frequency of 116 and 110GHz, respectively. The high frequency of flexible GFET demonstrated here paves the way for applications which require high flexibility and radio frequency operations.