Organic-organic epitaxy of incommensurate systems: quaterthiophene on potassium hydrogen phthalate single crystals.
Hot-wall epitaxy and molecular-beam epitaxy have been employed for growing quaterthiophene thin films on the (010) cleavage face of potassium hydrogen phthalate, and the results are compared in terms of film properties and growth mode. Even if there is no geometrical match between substrate and overlayer lattices, these films are epitaxially oriented. To investigate the physical rationale for this strong orientation effect, optical microscopy, atomic force microscopy, and X-ray diffraction are employed. A clear correlation between the morphology of the thin films and the crystallographic orientation is found. The results are also validated by surface potential calculations, which demonstrate the primary role played by the corrugation of the substrate surface.
Campione
Marcello
M
Department of Materials Science, University of Milan-Bicocca, Via R. Cozzi 53, I-20126 Milan, Italy.
Sassella
Adele
A
Moret
Massimo
M
Papagni
Antonio
A
Trabattoni
Silvia
S
Resel
Roland
R
Lengyel
Ondrej
O
Marcon
Valentina
V
Raos
Guido
G