High sensitivity of room-temperature terahertz photodetector based on silicon

Silicon (Si) is the most important semiconductor material broadly used in both electronics and optoelectronics. However, the performance of Si-based room temperature detectors is far below the requirements for direct detection in the terahertz (THz) band, a very promising electromagnetic band for the next-generation technology. Here, we report a high sensitivity of room temperature THz photodetector utilizing the electromagnetic induced well mechanism with an SOI-based structure for easy integration. The detector achieves a responsivity of 122 kV W^-1, noise equivalent power (NEP) of 0.16 pW Hz^-1/2, and a fast response of 1.29 μs at room temperature. The acquired NEP of the detector is ∼2 orders lower in magnitude than that of other types of Si-based detectors. Our results pave the way to realize Si-based THz focal plane arrays, which can be used in a wide range of applications, such as medical diagnosis, remote sensing, and security inspection.