关键词: 石墨烯/
太赫兹/
光生载流子/
光子发射
English Abstract
Photon-excited carriers and emission of graphene in terahertz radiation fields
Tao Ze-Hua,Dong Hai-Ming,
Duan Yi-Feng
1.School of Physical Science and Technology, China University of Mining and Technology, Xuzhou 221116, China
Fund Project:Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2015XKMS077) and the National Natural Science Foundation of China (Grant Nos. 11604380, 11774416).Received Date:27 July 2017
Accepted Date:16 October 2017
Published Online:20 January 2019
Abstract:Graphene exhibits excellent electronic and optical properties, which has been proposed as an advanced material for new generation of electronic and optical devices. We develop a detailed theoretical mode to investigate the optical properties of graphene-wafer systems. The photon-excited carriers and emission are obtained based on the mass-balance equation and the charge number conservation equation, which are derived from Boltzmann equation. The analytical results of photon excited carrier density and photon emission coefficient are achieved self-consistently in terahertz radiation fields. It is found that the photon excited carrier density increases with doped electron density or temperature decreasing. The higher the doped electron density and the lower the temperature, the larger the photon emission coefficient is. The optical emission increases with doped electron density increasing, and the optical emission increases with temperature decreasing. It shows that photon-excited carriers and emission of graphene can be effectively tuned by gate voltage. These theoretical results can be used to understand the relevant experimental findings. This theoretical study can benefit the applications in advanced optoelectronic devices based on graphene, especially terahertz devices.
Keywords: graphene/
terahertz/
photon-excited carrier/
photon-emission
