▎ 摘　　要

Current-voltage (I-V) characteristics of the graphene field effect transistors (GFETs) are measured by the dc, fast I-V (FIV), and pulsed I-V (PIV) methods and analyzed. The hysteresis and conductance in the dc measurement are affected by the sweeping bias range and direction. The I-V curves measured by the FIV method show reduced hysteresis and enhanced conductance at a faster sweeping rate, but are still affected by the sweeping bias range. By applying the PIV method, the hysteresis can be suppressed significantly while the conductance is improved by controlling turn-on, turn-off times (t(on) and t(off)) and the gate bias during t(off) (V-base) regardless of the sweeping bias range. With short t(on), long t(off), and V-base of 0 V, the hysteresis-free characteristics of GFETs are obtained.