Optoelectronic properties of graphene in the presence of optical phonon scattering
Optoelectronic properties of graphene in the presence of optical phonon scattering
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光学声子散射下石墨烯的光电特性
DOI：
10.1103/physrevb.82.125304
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发表时间：
2010-09
影响因子：
3.7
通讯作者：
徐文
中科院分区：
文献类型：
--
作者：
徐文
我们详细研究了石墨烯的光电性质。考虑到电子与光子和声子的相互作用，我们采用质量和能量平衡方程自洽地评估光生载流子密度，光学电导，和在线性偏振辐射场的存在下的透射系数。我们证明了光生载流子密度在电子-光子-声子共振跃迁附近增加。它们强烈地依赖于辐射强度和频率、温度和暗载流子密度。对于短波长的辐射L3 m，我们得到了普遍的光学电导0=e 2 /4。重要的是，在辐射波长范围4 - 100 m内存在光吸收窗口，这是由带间和带内光吸收所需的不同跃迁能量引起的。该窗口的位置和宽度敏感地依赖于系统的温度和载流子密度。这些理论结果与最近的实验结果一致，并表明石墨烯不仅在可见光区而且在中红外带宽中表现出重要的特征。
We study in detail the optoelectronic properties of graphene. Considering the electron interactions with photons and phonons, we employ the mass- and energy-balance equations to self-consistently evaluate the photoinduced carrier densities, the optical conductance, and the transmission coefficient in the presence of a linearly polarized radiation field. We demonstrate that the photoinduced carrier densities increase around the electron-photon-phonon resonant transition. They depend strongly on the radiation intensity and frequency, temperature, and dark carrier density. For short-wavelength radiation L3 m, we obtain the universal optical conductance 0=e 2 /4. Importantly, there exists an optical-absorption window in the radiation wavelength range 4‐100 m, which is induced by different transition energies required for interband and intraband optical absorption. The position and width of this window depend sensitively on the temperature and the carrier density of the system. These theoretical results are in line with recent experimental findings and indicate that graphene exhibits important features not only in the visible regime but also in the midinfrared bandwidth.