Current-induced enhancement of photo-response in graphene THz radiation detectors

Thermoelectric readout in a graphene terahertz (THz) radiation detector requires p- n junction across the channel. Even without an intentional junction, two latent junctions can exist vicinity of electrodes/antennas through proximity to metal. In symmetrical structure, these are connected back-to-back and therefore counterbalance each other with regard rectification ac signal. Because Peltier effect, small dc current results additional heating one cooling another thereby breaking symmetry. The then no longer cancel, resulting greatly enhanced rectified This allows simplifying design controlling sensitivity THz detectors.