Interfacial carrier dynamics of graphene on SiC, traced by the full-range time-resolved core-level photoemission spectroscopy.

Carrier dynamics through a heterointerface of a Dirac material and a semiconductor was studied by the measurement of the full-range time-resolved core-level photoemission spectroscopy using synchrotron radiation. The electron-hole recombination process during relaxation of the surface photovoltage effect was delayed in a graphene layer due to the bottleneck effect of Dirac cones. When an intermediate buffer layer exists, the recombination mainly takes place at the interfacial Si dangling-bond sites and the relaxation time shortens by one-order of magnitude. The present result demonstrates unusual carrier dynamics at a semiconductor surface, terminated by a layer of the Dirac material. [ABSTRACT FROM AUTHOR]