Regensburg 2019 – wissenschaftliches Programm
O 66.13: Poster
Mittwoch, 3. April 2019, 17:45–20:00, Poster B2
Hydrogenation of bilayer graphene with excited H2 — •Claus F. P. Kastorp1, Anders L. Jørgensen2, Martha Scheffler1, John D. Thrower1, David A. Duncan3, Tien-Lin Lee3, Liv Hornekaer1, and Richard Balog1 — 1Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark — 2The Mads Clausen Institute, SDU NanoSYD, Sønderborg, Denmark — 3Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, United Kingdom
Hydrogenation of single graphene layers provides a pathway for band gap tuning , while in bilayer graphene, functionalization could result in the formation of a diamane . STM measurements show that bilayer islands grown by CVD on Ir(111) are not functionalized by excited H2, but single layer areas are . Similarly, no hydrogenation is expected for full bilayer graphene samples produced via MBE on Ir(111).
I will present standard XPS and hard X-ray standing wave photoemission experiments that show a high degree of hydrogenation in MBE grown bilayer graphene when exposed to excited H2 molecules. Specifically, the components of the photoemission spectra that are associated with the bottom graphene layer, which is in direct contact with the iridium surface, indicate a level of hydrogenation that is comparable to the hydrogenation found for single layer graphene when exposed to excite H2. The top layer component appears mostly unaffected.
 Balog, et al. Nature materials 9.4 (2010): 315.
 Leenaerts, et.al., Phys. Rev. B, 80.24 (2009): 245422.
 Hansen, L.K., Ph.D. thesis, Aarhus University (2017).