Large-area graphene FET based broadband terahertz modulator

摘要

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 AbO3 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.