Carrier Recombination and Generation Rates for Intravalley and Intervalley Phonon Scattering in Graphene

TL;DR

This paper calculates electron-hole recombination and generation rates in graphene due to phonon scattering, showing how different phonon modes contribute and how rates depend on temperature and carrier densities, aligning well with experiments.

Contribution

It provides detailed theoretical calculations of recombination rates for intravalley and intervalley phonon scattering in graphene, including temperature and density dependence, validated by experimental data.

Findings

Recombination times range from less than a picosecond to hundreds of picoseconds.

Zone edge phonons contribute faster recombination than zone center phonons.

Calculated rates agree well with experimental measurements.

Abstract

Electron-hole generation and recombination rates for intravalley and intervalley phonon scattering in Graphene are presented. The transverse and the longitudinal optical phonon modes ($E_{2g}$-modes) near the zone center ($\Gamma$-point) contribute to intravalley interband carrier scattering. At the zone edge ($K(K')$-point), only the transverse optical phonon mode ($A'_{1}$-mode) contributes significantly to intervalley interband scattering with recombination rates faster than those due to zone center phonons. The calculated recombination times range from less than a picosecond to more than hundreds of picoseconds and are strong functions of temperature and electron and hole densities. The theoretical calculations agree well with experimental measurements of the recombination rates of photoexcited carriers in graphene.