Adsorption Of 5,10,15,20-Tetrakis (4-Bromophenyl) Porphyrin On Germanium(001)

A comparative study of 5,10,15,20-tetrakis(4-bromophenyl)porphyrin and 5,10,15,20-tetraphenylporphyrin molecules adsorbed on the Ge(001) surface, using scanning tunnelling microscopy and photoemission spectroscopy, reveals that the bromine substituents influence the adsorption mechanism significantly. A strong bromine-germanium interaction is observed, affecting the adsorption geometry of the entire molecule. Neither molecule appears to be mobile on the surface, which indicates additional interaction between the macromolecule and the surface.