EurekAlert February 3, 2021
As the radiation frequency is raised to the sub-terahertz (THz) domain, ac-to-dc conversion by conventional electronics becomes challenging and requires alternative rectification protocols. An international team of researchers (Russia, UK) address this challenge by tunnel field-effect transistors made of bilayer graphene (BLG). Taking advantage of BLG’s electrically tunable band structure, they created a lateral tunnel junction and couple it to an antenna exposed to THz radiation. The incoming radiation was then down-converted by the tunnel junction nonlinearity, resulting in high responsivity and low-noise detection. They demonstrated how switching from intraband Ohmic to interband tunneling regime can raise detectors’ responsivity by a few orders of magnitude, in agreement with the developed theory. The work opens prospects for applications of the graphene detector in wireless communications, security systems, radio astronomy, and medical diagnostics. It demonstrates a potential application of tunnel transistors for THz detection and reveals BLG as a promising platform for sub-terahertz domain…read more. Open Access TECHNICAL ARTICLE
Dual-gated bilayer graphene THz detector. Credit: Nature Communications volume 12, Article number: 543 (2021)