碟形天线耦合的CVD石墨烯室温太赫兹探测器

CVD Graphene Terahertz Detector Coupled by Bow-tie Antenna at Room Temperature

基于本征高迁移率、无能隙光谱以及非特征频率吸收的特性,石墨烯在太赫兹频段的调制器和探测器应用被予以厚望。制备了碟形天线耦合的CVD石墨烯场效应晶体管太赫兹探测器,实现了室温的高灵敏太赫兹探测。采用Au膜辅助转移技术屏蔽了有机物对石墨烯的沾污,配合自对准工艺控制了栅源间寄生效应,石墨烯器件场效应迁移率达7000 cm^(2)/(V·s),且在室温下表现出较高的太赫兹探测灵敏度,0.3 THz频率下器件的电压响应率为50 V/W,噪声等效功率为58 pW/Hz0.5。

Owing to its high carrier mobility,gapless spectrum and frequency-independent absorption,graphene is a very promising material for the development of detectors and modulators in the terahertz frequency band.Here,the terahertz detectors with high-sensitivity at room temperature based on bow-tie antenna-coupled CVD graphene field-effect transistors(FETs)were demonstrated.Au film was employed as the assistant transfer layer,which kept CVD graphene free from organic contaminations,together with self-aligned process that minimizes the ungated graphene region.As a result,the field effect mobility of graphene device is 7000 cm^(2)/(V·s)was obtained for graphene channel,and the graphene device shows high-sensitivity terahertz direct detecting at room temperature.The responsivity of the device is 50 V/W and noise equivalent power(NEP)is 58 pW/Hz0.5at 0.3 THz.