Probing post-growth hydrogen intercalation and H2 nanobubbles formation in graphene on Ge(110)

• Published in: Materials science in semiconductor processing 2024-04, Vol.173, p.108111, Article 108111
• Main Authors: Persichetti, L., Paoloni, D., Apponi, A., Camilli, L., Caporale, A., Babenko, V., Hofmann, S., Angelucci, M., Cimino, R., De Seta, M., Ruocco, A., Di Gaspare, L.
• Format: Article
• Language: English
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2024.108111

We investigate the reproducibility of repeated intercalation of hydrogen in graphene/Ge (110) and the formation of H2 nanobubbles after thermal treatments. By exploiting high-resolution electron energy loss, we obtain direct spectroscopic fingerprints of H2 trapped gas in the samples when nanobubbles are present and we are able to track the effectiveness of H intercalation via the Ge–H vibrational mode. We correlate the effectiveness of interface re-hydrogenation to the presence of structural defects in graphene as highlighted by Raman spectroscopy. The π-plasmon mode of graphene on Ge (110) is investigated as a function of the hydrogen presence at the interface, revealing that, independent of the hydrogen intercalation status, graphene is weakly interacting on Ge (110).