Hot carrier and hot phonon coupling during ultrafast relaxation of photoexcited electrons in graphene
Monte-Carlo, Método de
Hot phonon effect
3307 Tecnología electrónica
Fecha de publicación
AIP Publishing LLC
Iglesias, J.M., Martín, M.J., Pascual, E. and Rengel, R. (2016). Hot carrier and hot phonon coupling during ultrafast relaxation of photoexcited electrons in graphene. Applied Physics Letterrs, 108 (4), 043105
[EN]We study, by means of a Monte Carlo simulator, the hot phonon effect on the relaxation dynamics in photoexcited graphene and its quantitative impact as compared to considering an equilibrium phonon distribution. Our multi-particle approach indicates that neglecting the hot phonon effect significantly underestimates the relaxation times in photoexcited graphene. The hot phonon effect is more important for a higher energy of the excitation pulse and photocarrier densities between 1 and 3x10^12 cm^-2. Acoustic intervalley phonons play a non-negligible role, and emitted phonons with wavelengths limited up by a maximum (determined by the carrier concentration) induce a slower carrier cooling rate. [EN]Intrinsic phonon heating is damped in graphene on a substrate due to additional cooling pathways, with the hot phonon effect showing a strong inverse dependence with the carrier density.