Author/Authors :
Ostler، نويسنده , , Markus and Fromm، نويسنده , , Felix and Koch، نويسنده , , Roland J. and Wehrfritz، نويسنده , , Peter and Speck، نويسنده , , Florian and Vita، نويسنده , , Hendrik and Bِttcher، نويسنده , , Stefan and Horn، نويسنده , , Karsten and Seyller، نويسنده , , Thomas، نويسنده ,
Abstract :
Intercalation of various elements has become a popular technique to decouple the buffer layer of epitaxial graphene on SiC(0 0 0 1) from the substrate. Among many other elements, oxygen can be used to passivate the SiC interface, causing the buffer layer to transform into graphene. Here, we study a gentle oxidation of the interface by annealing buffer layer and monolayer graphene samples in water vapor. X-ray photoelectron spectroscopy demonstrates the decoupling of the buffer layer from the SiC substrate. Raman spectroscopy is utilized to investigate a possible introduction of defects. Angle-resolved photoemission spectroscopy shows that the electronic structure of the water vapor treated samples. Low-energy electron microscopy (LEEM) measurements demonstrate that the decoupling takes place without changes in the surface morphology. The LEEM reflectivity spectra are discussed in terms of two different interpretations.
