液氮制冷的AlGaN/GaN HEMT太赫兹探测器阵列特性研究  

Research on the characteristics of AlGaN/GaN HEMT terahertz detector array cooled by liquid nitrogen

作　　者：吴昊[1,2,3] 朱一帆 丁青峰[1,2,3] 张金峰 上官阳 孙建东 秦华 Wu Hao;Zhu Yifan;Ding Qingfeng;Zhang Jinfeng;Shangguan Yang;Sun Jiandong;Qin Hua(Key Laboratory of Nanodevices and Applications,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;Key Laboratory of Nanodevices of Jiangsu Province,Key Laboratory of Nanodevices and Applications,Chinese Academy of Sciences,Suzhou 215123,China;School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院,苏州纳米技术与纳米仿生研究所,纳米器件与应用重点实验室,江苏苏州215123 [2]上海科技大学物质科学与技术学院,上海201210 [3]中国科学院纳米器件与应用重点实验室,江苏省纳米器件重点实验室,江苏苏州215123 [4]中国科学技术大学,纳米技术与纳米仿生学院,安徽合肥230026

出　　处：《红外与激光工程》2022年第12期286-292,共7页Infrared and Laser Engineering

基　　金：国家自然科学基金(61771466,61775231);中国科学院青年创新促进会(Y2021089);江苏省重点研发计划(BE2018005)。

摘　　要：为充分发挥AlGaN/GaN高电子迁移率晶体管(High-Electron-Mobility Transistor,HEMT)太赫兹探测器阵列的高电子迁移率优势,文中研究了HEMT太赫兹探测器阵列在77K下的探测特性。使用液氮杜瓦为降温主体搭建了适用于焦平面(Focal-Plane Array,FPA)芯片的低温系统,实现了对焦平面芯片常温与低温下的对比测试。温度从300 K降到77 K时,探测器阵列像元的平均响应度提高近3倍,平均噪声有小幅增大,340GHz时平均噪声等效功率(Noise Equivalent Power,NEP)从45.1pW/Hz^(1/2)降低到了19.4pW/Hz^(1/2),灵敏度提高两倍以上。与硅透镜耦合的单元探测器相比,阵列像元的灵敏度提升仍有较大空间。主要是由于各像素点最佳工作电压的不一致,导致在给定统一工作电压下像元间的响应度和噪声都表现出较大的离散性,文中讨论了降低最佳工作电压离散度的可能解决方案。In order to take full advantage of the high electron mobility of the AlGaN/GaN high-electron-mobility transistor(HEMT)terahertz detector array,the detection characteristics of the HEMT terahertz detector array at77 K are studied.A low temperature system suitable for the focal-plane array(FPA)chip is built based on liquid nitrogen Dewar.Comparison tests of the FPA at room temperature and low temperature is realized.When the temperature is lowered from 300K to 77K,the average responsivity of the detector array pixels increase by about3 times,the average noise increases slightly,and the average noise-equivalent power(NEP)is reduced from 45.1pW/Hz^(1/2)to 19.4pW/Hz^(1/2)at 340 GHz,i.e.,the sensitivity is more than doubled.Compared with the single detector coupled with silicon lens,there is still a lot of room for improving the sensitivity of array pixels.It is mainly due to the inconsistency of the optimal working voltage of each pixel,that leads to a large dispersion of the responsivity and noise between pixels under a given unified working voltage.Possible solutions to the problem of inconsistent optimal working voltage are discussed in this paper.

关 键 词：太赫兹探测器 低温焦平面 成像芯片 氮化镓HEMT 

分 类 号：TN386.3[电子电信—物理电子学]