基于偶极天线的石墨烯太赫兹光热电探测器研究

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中图分类号： TN362 文献标志码：A

Abstract： Photothermoelectric terahertz detectors can effectively convert optical signal into electrical signals， and have significant advantages such as zero bias， room-temperature operating condition， high sensitivity，etc.， which has great potential applications in secu rity imaging， nondestructive testing and biomedicine. We design a graphene terahertz detector based on photothermoelectric effect. The detector uses the dipole antenna as an optical coupling structure to localize the electromagnetic energy into the slit region of the antenna， enhance the local electric field by improving the light absorption， and provide an asymmetric temperature gradient distribution for the carrier movement in graphene. The main performance indexes of the detector are response rate Rv and noise equivalent power （NEP）. At room temperature and in zero-bias mode， the local electric field is increased by1 to 2 orders of magnitude，and the noise equivalent power is as low as 22pW⋅Hz-1/2 ， indicating that the resonant coupling structure can effectively realize the local enhancement of electromagnetic energy，and has important applications in terahertz highly sensitive detection.

Keywords： terahertz; graphene; dipole antenna; detector

引言

太赫兹波是指频率在 0.1～10THz（0.03～ 3mm ）之间的电磁波，该频段处于电子学与光子学过渡区[1-3]。（剩余8340字）