Sub-terahertz FET detector with self-assembled Sn-nanothreads

We report on the design, evaluation and fabrication of the sub-terahertz (sub-THz) detector using a GaAs gated field-effect transistor with a buried quasi-two-dimensional electron gas created by the self-assembled Sn-nanothreads (Sn-NTs) embedded into the GaAs channel. This GaAs-Sn-NTs detector efficiently detects a sub-THz radiation at cryogenic and room temperatures (CT and RT, respectively). Two possible detection mechanisms are the bolometric mechanism due to electron heating by the sub-THz radiation and the mechanism related to the rectification of the decayed plasmonic oscillations. We developed a classical self-consistent device model of the bolometric detection involving the Poisson equation and the electron density of states and estimated responsivity and noise-equivalent power of the detector. The measured I-V characteristics and the photoresponse to the incident sub-THz radiation at CT and RT are in reasonable agreement with our model. The detector demonstrates a better performance than semiconductor-based hot-electron bolometers and quantum-well/dot IR and THz photodetectors.