Dr. Jonas Warmuth, Institute for Applied Physics, University of Hamburg, Germany

Bismuth Intercalated Graphene on Iridium Probed by STM and ARPES

The talk reports on the investigation of monolayer graphene on a single iridium crystal with intercalated bismuth by means of scanning tunneling microscopy (STM) and angle-resolved photoelectron spectroscopy (ARPES). The STM measurements reveal and characterize a complex periodic surface structure observed on the graphene monolayer. 

Strong evidence is presented that a bismuth iridium surface alloy induces the surface structure. The sample coverage of this surface alloy was successfully increased to 95% enabling spatial averaging measurements as ARPES to probe the band structure of this system. The performed ARPES measurements reveal that the bismuth iridium surface alloy n-dopes the graphene pi-band and opens a band gap at the Dirac point.

Host: Associate professor Jeppe Vang Lauritsen, iNANO & Department of Physics and Astronomy, Aarhus University