单层与双层石墨烯的光学吸收性质研究  

Optical absorptions in monolayer and bilayer graphene

作　　者：陈英良[1] 冯小波[1] 侯德东[1] 

机构地区：[1]云南师范大学物理与电子信息学院,昆明650500

出　　处：《物理学报》2013年第18期416-421,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11064017);云南省应用基础研究面上项目(批准号:2010ZC078;2010CD047)资助的课题~~

摘　　要：采用紧束缚模型分别描述单层、双层石墨烯的能带结构，利用光子．电子相互作用的二阶微扰理论分别计算单光子和双光子吸收系数．计算结果表明：单层石墨烯单光子吸收系数为常数，约为6．8X107m-1，即单层石墨烯对入射光的吸收率约为213％；双层石墨烯的单光子吸收比单层石墨烯的单光子吸收强，且随入射光波长呈分段性变化．单层石墨烯的双光子吸收系数与波长r4成正比；双层石墨烯双光子吸收系数在红外波段（-3100nm处）有一个很强的共振吸收峰．研究结果可为石墨烯材料在光电子器件的研究和制作方面提供指导．We theoretically simulate one-photon and two-photon absorption spectra for monolayer and bilayer graphene employing the second-order perturbation theory of the electron-photon interaction. The tight-binding model is used to describe the band structure of graphene. The results show that one-photon absorption coefficient of monolayer graphene is a constant about 6.8 ~ 107 m-~, demon- strafing that the absorptivity of incident light in monolayer graphene approximates to 2.3%. The one-photon absorption coefficient of bilayer graphene changes sectionally with the wavelength and is greater than that of monolayer graphene. The two-photon absorption coefficient of monolayer graphene is proportional to ~4. The two-photon absorption coefficient of bilayer graphene exhibits a giant resonance absorption peak in the infrared （~3100 nm） region. Our results will provide theoretical guidance for the application of graphene in the research field of optoelectronic devices.

关 键 词：石墨烯 光学吸收 紧束缚模型 

分 类 号：O482.3[理学—固体物理]