中国物理B ›› 2019, Vol. 28 ›› Issue (5): 58501-058501.doi: 10.1088/1674-1056/28/5/058501
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
Zhi-Feng Tian(田志锋), Peng Xu(徐鹏), Yao Yu(余耀), Jian-Dong Sun(孙建东), Wei Feng(冯伟), Qing-Feng Ding(丁青峰), Zhan-Wei Meng(孟占伟), Xiang Li(李想), Jin-Hua Cai(蔡金华), Zhong-Xin Zheng(郑中信), Xin-Xing Li(李欣幸), Lin Jin(靳琳), Hua Qin(秦华), Yun-Fei Sun(孙云飞)
Zhi-Feng Tian(田志锋)1,2,3,5, Peng Xu(徐鹏)1,4, Yao Yu(余耀)1,5, Jian-Dong Sun(孙建东)1, Wei Feng(冯伟)1,6, Qing-Feng Ding(丁青峰)1,2, Zhan-Wei Meng(孟占伟)1,4, Xiang Li(李想)1,6, Jin-Hua Cai(蔡金华)1, Zhong-Xin Zheng(郑中信)7, Xin-Xing Li(李欣幸)1, Lin Jin(靳琳)1, Hua Qin(秦华)1,2,5, Yun-Fei Sun(孙云飞)8
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/Hz1/2 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/Hz1/2 at 300 K to 60 pW/Hz1/2 at 448 K mainly due to the reduction in mobility. Above 448 K, the NEP is increased up to 1000 pW/Hz1/2 due to the strongly enhanced noise. The sensitivity can be recovered by cooling the detector back to room temperature.
中图分类号: (Photodetectors (including infrared and CCD detectors))