Abstract-Two-terminal terahertz detectors based on AlGaN/GaN high-electron-mobility transistors

Applied Physics Letters

Jiandong Sun, Zhipeng Zhang,  Xiang Li, Hua Qin, Yunfei Sun, Yong Cai, Guohao Yu, Zhili Zhang, Jinfeng Zhang, Yang Shangguan, Lin Jin, Xinxing Li, Baoshun Zhang,  V. V. Popov,

(a) A top view of the detector. (b) Central gate and fluorine ion implantation area of the detector. (c) A schematic cross section of the detector corresponding to the dotted red line in (b). (d) A color-scale 2D plot of the spatial distribution of the mixing factor from a FDTD simulation at 648 GHz.

https://aip.scitation.org/doi/abs/10.1063/1.5114682

We report an approach to make two-terminal antenna-coupled AlGaN/GaN high-electron-mobility-transistor self-mixing terahertz detectors. Fluorine ion implantation is used to increase the threshold voltage of the AlGaN/GaN two-dimensional electron gas. An optimal implantation dose can be reached so that the detector responsivity is maximized at zero gate voltage or with the gate floating. The relationship between the ion dosage and the threshold voltage, electron mobility, electron density, responsivity, and noise-equivalent power (NEP) is obtained. A minimum optical NEP of 47  W/Hz⎯⎯⎯⎯⎯√$47\hspace{0.17em}\hspace{0.17em}\mathrm{W}/\sqrt{\text{Hz}}$ is achieved from a two-terminal detector at 0.65 THz. The capability of two-terminal operation allows for the design of a large array of antenna-coupled high-electron-mobility transistor detectors without the demanding needs of routing negative gate voltage lines around the antenna array and minimizing the gate leakage current.

The authors acknowledge support from the National Key Research and Development Program of China (No. 2016YFF0100501), the China National Natural Science Foundation (Nos. 61771466 and 61775231), the Youth Innovation Promotion Association CAS (No. 2017372), the Six Talent Peaks Project of Jiangsu Province, China (No. XXRJ-079), and the Russian Foundation for Basic Research (No. 17-52-53063).