Effects of carrier-carrier scattering on population inversion in graphene under pulse photoexcitation

International Scientific Seminars on "Fundamental and Applied Problems of Photonics and Condensed Matter Physics"

Satou, Akira^1 ; Ryzhii, Victor^1 ; Otsuji, Taiichi^1

Tohoku University, Research Institute of Electrical Communication, 2-1-1 Katahira, Aoba-ku, Sendai

980-8577, Japan^1

关键词: Carrier relaxation dynamics;    Carrier-carrier scattering;    High dielectric constants;    Photogeneration;    Population inversions;    Relaxation dynamics;    Surrounding materials;    Terahertz region;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/584/1/012018/pdf
DOI  :  10.1088/1742-6596/584/1/012018

来源: IOP

【 摘 要 】

We study the carrier relaxation dynamics in intrinsic graphene after pulse photoexcitation and reveal effects of intraband carrier-carrier scattering on population inversion in the terahertz region, by conducting simulation based on the quasi-classical Boltzmann equation. It is demonstrated that by changing the dielectric constant of the surrounding materials the rate of carrier-carrier scattering can be controlled and the relaxation dynamics differs for cases with low and high dielectric constants. It is also found that the Pauli blocking of photogeneration in case of the pulse photoexcitation causes decrease in the photocarrier concentration and thus weakening of population inversion with higher dielectric constant.