On the structural evolution of low-dimensional germanium phases forming 2D germanene on Ag(111) studied by XPS and XPD*

In the last decade, research on 2D-materials has expanded massively due to the popularity of graphene. Although the chemical engineering of two-dimensional elemental materials, as well as heterostructures has been extensively pursued, the fundamental understanding of the synthesis of 2D-materials is not yet complete. Structural parameters, such as the buckling or substrate bonding of a 2D-material directly affect its electronic characteristics, like the famous Dirac-behavior. 

In order to improve the understanding of the element-specific growth and the associated tuning of material properties of two-dimensional films, we performed a study on the structural evolution of the promising 2D material germanene on Ag(111). Using powerful surface analysis tools like low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and x-ray photoelectron diffraction (XPD) with synchrotron radiation, we will present models of the atomic and chemical structure of germanene phases with focus on the structure and electronic interaction at the interface.