Recombination channels in optically excited graphene

Artikel i vetenskaplig tidskrift, 2015

We present a theoretical study on the efficiency of non-radiative recombination channels in optically excited graphene on a substrate. We find that depending on the strength of the excitation pulse and the dielectric constant of the applied substrate, either Auger or phonon-induced recombination prevails. The favorable conditions for Auger recombination are (i) strong excitation regime providing a large number of scattering partners and (ii) low-dielectric substrates, which only weakly screen the Coulomb interaction. The gained insights are important for achieving a population inversion in graphene that is temporally limited by the presented recombination channels.