Triangular-Pulse Measurement for Hysteresis of High-Performance and Flexible Graphene Field-Effect Transistors

We use a triangular-pulse measurement technique to obtain the hysteretic electrical characteristics of flexible graphene field-effect transistors (GFETs). To minimize charge trapping, the gate-voltage scanning rate was controlled (up to 2
${\rm V}/\mu{\rm s}$
) by varying the triangular-pulse rise and fall times. This method makes it possible to measure the intrinsic-like transfer characteristics of chemical vapor deposition graphene devices. The maximum electron (hole) mobility measured by a dc measurement is
${\sim}{4800}$
(5200)
${\rm cm}^{2}/{\rm Vs}$
, whereas the maximum electron (hole) mobility measured by the triangular-pulse technique with a gate-voltage scanning rate of 0.4
${\rm V}/\mu{\rm s}$
is
$\sim{10600}$
(8500)
${\rm cm}^{2}/{\rm Vs}$
. For measurements with a triangular gate pulse, the shift of the Dirac voltage is less than that measured by the dc method. These results indicate that the triangular-gate-pulse measurement is a promising technique with which to determine the intrinsic properties and ambipolar transfer characteristics of GFETs.