Responsivity and noise characteristics of AlGaN/GaN-HEMTterahertz detectors at elevated temperatures  

作　　者：Zhi-Feng Tian Peng Xu Yao Yu Jian-Dong Sun Wei Feng Qing-Feng Ding Zhan-Wei Meng Xiang Li Jin-Hua Cai Zhong-Xin Zheng Xin-Xing Li Lin Jin Hua Qin Yun-Fei Sun 田志锋;徐鹏;余耀;孙建东;冯伟;丁青峰;孟占伟;李想;蔡金华;郑中信;李欣幸;靳琳;秦华;孙云飞(Key Laboratory of Nano Devices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences;School of Physical Science and Technology, Shanghai Technology University;Shanghai Institute of Ceramics, Chinese Academy of Sciences;University of Chinese Academy of Sciences;Nano Science and Technology Institute, University of Science and Technology of China;School of Nano Technology and Nano Bionics, University of Science and Technology of China;Beijing Huahang Radio Measurement & Research Institute;College of Electronic and Information Engineering, Suzhou University of Sciences and Technology)

机构地区：[1]Key Laboratory of Nano Devices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences [2]School of Physical Science and Technology, Shanghai Technology University [3]Shanghai Institute of Ceramics, Chinese Academy of Sciences [4]University of Chinese Academy of Sciences [5]Nano Science and Technology Institute, University of Science and Technology of China [6]School of Nano Technology and Nano Bionics, University of Science and Technology of China [7]Beijing Huahang Radio Measurement & Research Institute [8]College of Electronic and Information Engineering, Suzhou University of Sciences and Technology

出　　处：《Chinese Physics B》2019年第5期355-360,共6页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2016YFF0100501);the National Natural Science Foundation of China(Grant Nos.61771466,61775231,and 61611530708);the Six Talent Peaks of Jiangsu Province,China(Grant No.XXRJ-079);the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2017372)

摘　　要：The responsivity and the noise of a detector determine the sensitivity. Thermal energy usually affects both the responsivity and the noise spectral density. In this work, the noise characteristics and responsivity of an antenna-coupled AlGaN/GaN high-electron-mobility-transistor(HEMT) terahertz detector are evaluated at temperatures elevated from 300 K to 473 K. Noise spectrum measurement and a simultaneous measurement of the source–drain conductance and the terahertz photocurrent allow for detailed analysis of the electrical characteristics, the photoresponse, and the noise behavior. The responsivity is reduced from 59 mA/W to 11 mA/W by increasing the detector temperature from 300 K to 473 K. However,the noise spectral density maintains rather constantly around 1–2 pA/Hz^(1/2) at temperatures below 448 K, above which the noise spectrum abruptly shifts from Johnson-noise type into flicker-noise type and the noise density is increased up to one order of magnitude. The noise-equivalent power(NEP) is increased from 22 pW/Hz^(1/2) at 300 K to 60 pW/Hz^(1/2) at 448 K mainly due to the reduction in mobility. Above 448 K, the NEP is increased up to 1000 pW/Hz^(1/2) due to the strongly enhanced noise. The sensitivity can be recovered by cooling the detector back to room temperature.The responsivity and the noise of a detector determine the sensitivity. Thermal energy usually affects both the responsivity and the noise spectral density. In this work, the noise characteristics and responsivity of an antenna-coupled AlGaN/GaN high-electron-mobility-transistor(HEMT) terahertz detector are evaluated at temperatures elevated from 300 K to 473 K. Noise spectrum measurement and a simultaneous measurement of the source–drain conductance and the terahertz photocurrent allow for detailed analysis of the electrical characteristics, the photoresponse, and the noise behavior. The responsivity is reduced from 59 mA/W to 11 mA/W by increasing the detector temperature from 300 K to 473 K. However,the noise spectral density maintains rather constantly around 1–2 pA/Hz^(1/2) at temperatures below 448 K, above which the noise spectrum abruptly shifts from Johnson-noise type into flicker-noise type and the noise density is increased up to one order of magnitude. The noise-equivalent power(NEP) is increased from 22 pW/Hz^(1/2) at 300 K to 60 pW/Hz^(1/2) at 448 K mainly due to the reduction in mobility. Above 448 K, the NEP is increased up to 1000 pW/Hz^(1/2) due to the strongly enhanced noise. The sensitivity can be recovered by cooling the detector back to room temperature.

关 键 词：TERAHERTZ detection GALLIUM NITRIDE noise SPECTRUM RESPONSIVITY 

分 类 号：O4[理学—物理]