High Temperature Terahertz Detectors Realized by a GaN High Electron Mobility Transistor

In this work, a high temperature THz detector based on a GaN high electron mobility transistor (HEMT) with nano antenna structures was fabricated and demonstrated to be able to work up to 200°C. The THz responsivity and noise equivalent power (NEP) of the device were characterized at 0.14 THz radiation over a wide temperature range from room temperature to 200 °C. A high responsivity R_v of 15.5 and 2.7 kV/W and a low NEP of 0.58 and 10 pW/Hz^0.5 were obtained at room temperature and 200 °C, respectively. The advantages of the GaN HEMT over other types of field effect transistors for high temperature terahertz detection are discussed. The physical mechanisms responsible for the temperature dependence of the responsivity and NEP of the GaN HEMT are also analyzed thoroughly.