Responsivity and noise characteristics of AlGaN/GaN-HEMT terahertz detectors at elevated temperatures*
| Autor: | Lin Jin, Jiandong Sun, Zhi-Feng Tian, Xinxing Li, Yao Yu, Zhongxin Zheng, Hua Qin, Peng Xu, Qingfeng Ding, Wei Feng, Xiang Li, Yunfei Sun, Jin-Hua Cai, Zhan-Wei Meng |
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| Rok vydání: | 2019 |
| Předmět: |
Photocurrent
Materials science business.industry Terahertz radiation Noise spectral density Detector General Physics and Astronomy Gallium nitride 02 engineering and technology High-electron-mobility transistor 021001 nanoscience & nanotechnology 01 natural sciences Noise (electronics) chemistry.chemical_compound Responsivity chemistry 0103 physical sciences Optoelectronics 010306 general physics 0210 nano-technology business |
| Zdroj: | Chinese Physics B. 28:058501 |
| ISSN: | 1674-1056 |
| DOI: | 10.1088/1674-1056/28/5/058501 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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