蝶形天线增强的HEMT室温太赫兹探测器

Room Temperature Terahertz Detectors Based on HEMTs Enhanced by Bowtie Antennas

介绍了一种基于GaN/AlGaN高电子迁移率晶体管(HEMT)的高速、高灵敏度室温太赫兹探测器。在太赫兹波辐射下,HEMT源漏端产生直流光电流,并能被栅压灵敏地调控。探测器中新颖的蝶形天线设计使接收到的太赫兹电场得到显著增强,提高了探测器的响应度。通过测量探测器对不同偏振方向的太赫兹光的响应,有效验证了蝶形天线对太赫兹电场的增强作用。室温下,探测器的等效噪声功率约为5×10-10W/Hz21,平均响应度达42mA/W。实验结果表明,光电流的产生与二维电子气沟道的场效应特性和入射太赫兹波电场在电子沟道中的分布密切相关。自混频理论能很好地描述实验结果。

A room temperature terahertz（THz） detector based on a GaN/AlGaN high electron mobility transistor（HEMT） enhanced by bowtie antenna was presented.Due to its micron sized field effect nature and antenna enhancement,the detector is of high speed and high responsivity.Under terahertz irradiation,the direct photocurrent was observed when the electron channel was strongly modulated by the gate voltage.The received terahertz electric field was significantly enhanced and the detection response was improved due to the novel bowtie antenna of the detector.Through measuring the detector for different polarization terahertz light response,the polarization dependence of photocurrent was verified in accordance with the design of bowtie antennas.The noise equivalent power（NEP） and the average responsivity were estimated to be 5×10-10 W/Hz12 and 42 mA/W at the room temperature of 300 K,respectively.Both the experimental and simulation results show that the photocurrent originates from selfmixing of the incident terahertz wave.The selfmixing can be further enhanced by improving the field effect of two-dimensional electron gas（2DEG） and optimizing the distribution of terahertz field in the electron channel.The expe-rimental results can be well described by selfmixing theory.