Аннотация:In this work, we fabricated graphene terahertz detectors with dual-side metallic gate. Detectors using only one set of gates showed a monotonic change in responsivity as gate voltage changed, with a peak value of ~ 12 V/W within 0.1 THz, and no distinguishable response above 0.1 THz. The dominating mechanism was found to be the photo-thermoelectric (PTE) effect. Detectors using multiple sets of gates showed monotonic and non-monotonic change in responsivity as gate voltage changed, with peak responsivity of 462 V/W at 0.082 THz and 198 V/W at 2.52 THz. In the frequency ranges where the responsivity changed monotonically, the dominating mechanism was found to be the PTE effect for frequencies. In the frequency ranges where responsivity changed non-monotonically, the dominating mechanism was found to alternate between the plasmon rectification effect and the PTE effect at different gate voltage. The excitation of graphene plasmons promised non-degrading responsivity below 0.105 THz and at 2.52 THz.
