Terahertz detection in a multi-gate high electron mobility transistor

We observe the THz response of a multi-gate high electron mobility transistor detector structure. These devices are fabricated from single heterostructure GaAs/AlGaAs material and feature three gates: a ‘source gate’ adjacent to source terminal, a ‘drain gate’ adjacent to drain terminal, and a narrow ‘barrier gate’ biased to pinch-off that serves as a bolometric sensor. Bias dependent measurements of the responsivity indicate coupling to free carriers located in the non-metalized slots between gates. The absorbed terahertz radiation is sensed by the hot electron bolometer formed by the pinched off channel under the barrier gate.