Leiden University Student Repository

Jong, Luuk de (2024)

Spectroscopy of Caesium Oxide on Graphene using Low Energy Electron Microscopy

Bachelor thesis | Natuurkunde (BSc)

Van der Waals materials like graphite consist of stacked atomically thin layers. These two-dimensional layers have different electronic properties from their three-dimensional counterparts. Low energy electron microscopy (LEEM) is well suited to the study of these materials, but can only measure above the work function of the material. Deposition of caesium and oxygen is known to lower the work function through the formation of strong surface dipoles. In this research, the LEEM reflectivity spectrum of epitaxial few-layer graphene on silicon carbide (0001) during the deposition of caesium and oxygen is analysed to better understand this process. Caesiation is found to bring down the work function by approximately 1.8 eV, but subsequent oxygenation increases the work function by approximately 0.8 eV. For smaller amounts of caesium, reducing the work function by only 0.5 eV, oxygenation is not found to have any significant effect.

Author

Jong, Luuk de

Faculty

Faculty of Science

Supervisors

Stam, W.G.
Molen, S.J. van der

ECTS Credits

3

Language

en