基于谐振腔增强型石墨烯光电探测器的设计及性能分析  

Design and performance analysis of microcavity-enhanced graphene photodetector

作　　者：梁振江[1] 刘海霞[1] 牛燕雄[1] 尹贻恒[1] 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《物理学报》2016年第13期297-303,共7页Acta Physica Sinica

基　　金：北京市自然科学基金(批准号:7152089)资助的课题~~

摘　　要：提出了一种具有超薄有源层的谐振腔增强型石墨烯光电探测器的设计方法,利用谐振腔结构可以将光场限制在腔内,有效增强探测器的吸收.通过研究谐振腔内光场谐振条件及谐振模式下探测器响应度增强的机理,建立了驻波效应下谐振腔增强型石墨烯光电探测器光吸收模型,仿真分析谐振腔反射镜反射率、谐振腔腔长对于腔内光场增强器件性能的影响.理论分析表明,谐振腔增强型石墨烯光电探测器在850 nm处响应度可达0.5 A/W,相比无腔状态下提高了32倍;半高全宽为10 nm.采用谐振腔结构能够提高石墨烯光电探测器件的光电响应,为解决光电探测器响应度与响应速度之间的相互制约关系提供了途径.There is an increasing interest in grapheme photodetector for its applications, because graphene has rich optical and electronic properties, including zero band gap, high mobility and special optical absorption properties. A design of microcavity-enhanced photodetector based on ultra-thin graphene is proposed in this paper： detector absorption can be effectively improved by confining the light field in the microcavity. Through studying the light field resonant condition in the microcavity and enhanced mechanism of detector responsivity under resonant mode, the light absorption model of a microcavity-enhanced graphene photodetector under standing wave effect is established; it is analyzed that the influences of microcavity mirror reflectivity and length on detector performance are increased by light field. Further the optimal structure parameters and performance evaluations of microcavity-enhanced graphene photodetector at different incident wavelengths are demonstrated. Theoretical analysis shows that under the standing wave effect the effective absorption coefficient of monolayer graphene at the antinode is one multiple enlargement compared with no cavity; the microcavity length and topbottom mirror reflectivity directly affect the optical total phase during light folding back at one time in the microcavity, and the shift of the total optical phase changes the full width at half maximum（FWHM） of the responsivity of the microcavity-enhanced graphene photodetector. Through coordinating the relations among the microcavity length and reflectivities of two mirrors and the incident wavelength, it can be realized that the photodetector has a good characteristic of wavelength selectivity. At a nominal operating wavelength of 850 nm, the presented microcavityenhanced graphene photodetector can reach a responsivity of 0.5 A/W, 32-fold increase compared with monolayer graphene photodetector with no cavity and FWHM can reach 10 nm, indicating that the designed photodetector has a high responsivity and a good charactor

关 键 词：谐振腔 石墨烯光电探测器 响应度 波长选择性 

分 类 号：TN36[电子电信—物理电子学]