Large-area graphene FET based broadband terahertz modulator

We present two kinds of broadband terahertz wave modulator fabricated with large-area graphene-based field-effect transistors (GFET). One is with improved modulation depth and switch speed by cautiously selecting an ultrathin AbO
₃
film (60 nm) as the gate dielectric materials, which reduces the Coulomb impurity scattering and cavity effect, and thus greatly improves the modulation performance. Another one is a flexible THz modulator based on the coplanar-gate GFET structure of ion-gel/graphene/polyethylene terephthalate. The proposed THz modulator shows superior flexible performance and a large modulation depth of 38%, where the modulation properties can be maintained almost unchanged before and after bending 1000 times.