Year: 2010
Type: article
Abstract: Graphene as a zero-bandgap semiconductor is an ideal model structure to study the carrier relaxation channels, which are inefficient in conventional semiconductors. In particular, it is of fundamental interest to address the question whether Auger-type processes significantly influence the carrier dynamics in graphene. These scattering channels bridge the valence and conduction band allowing carrier multiplication, a process that generates multiple charge carriers from the absorption of a single photon. This has been suggested in literature for improving the efficiency of solar cells. Here we show, based on microscopic calculations within the density matrix formalism, that Auger processes do play an unusually strong role for the relaxation dynamics of photoexcited charge carriers in graphene. We predict that a considerable carrier multiplication takes place, confirming the potential of graphene as a new material for high-efficiency photodevices.
Source: Nano Letters
DOI: 10.1021/nl1024485
Authors: Torben Winzer, Andreas Knorr, Ermin Malic
Institution: Technische Universität Berlin
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1964563420