▎ 摘　　要

The effect of ambipolar carriers on terahertz self-mixing is theoretically investigated in an antenna-coupled graphene field-effect terahertz (GFET) detector by taking into account the spatial distributions of the charge carriers and the terahertz field. The model predicts that the charge and field distributions can be tuned by the gate voltage so that they match up with each other and enhance the photocurrent. Such a cooperative self-mixing does not occur in unipolar FET detectors. A GFET detector with a moderate carrier mobility could offer current responsivity of a few A/W and noise-equivalent power below 50 pW/root Hz at room temperature. (C) 2013 AIP Publishing LLC.