High-Performance Room-Temperature Terahertz Photodetection Using 2-Dimensional Electron Gas Channel Transport

Room-temperature (RT) terahertz (THz) detection finds widespread applications in security inspection, communication, biomedical imaging, and scientific research. However, the state-of-the-art detection strategies are still limited by issues such as low sensitivity, narrow response range, slow response speed, complex fabrication techniques, and difficulties in scaling up to large arrays. Here, we present a high-sensitivity, broadband-response, and high-speed RT THz detection strategy by utilizing a deep subwavelength metal-semiconductor-metal (MSM) structure. The spontaneously formed 2-dimensional electron gas (2DEG) at the CdTe/PbTe interface provides a superior transport channel characterized by high carrier concentration, low scattering, and high mobility. The synergy of the electromagnetic induced well effect formed in the MSM structure, and the efficient and rapid transport capabilities of the 2DEG channel give rise to an impressive performance improvement. The proposed 2DEG photodetector exhibits a broad frequency range from 22 to 519 GHz, an ultralow noise equivalent power of 3.0 × 10^-14 W Hz^-1/2 at 166 GHz, and a short response time of 6.7 μs. This work provides an effective route for the development of high-performance RT THz detection strategies, paving the way for enhanced THz technology applications.