Para-sexiphenyl thin films on KCl(1Â 0Â 0) surfaces: Growth morphologies and their individual epitaxial order

This work focuses on structural and morphological studies of para-sexiphenyl thin films grown on freshly cleaved KCl(1 0 0) surfaces. Atomic force microscopy images show different morphologies, namely terrace like growth and different kinds of needle like growths. By X-ray diffraction methods different crystal alignments of the organic film on the substrate are found. The different crystal alignments are assigned to the observed morphologies by transmission electron microscopy and diffraction. Regarding the incommensurate interfaces (on the part of the surface unit cells) it is concluded that the epitaxy is dominated by an alignment of small crystallites on the KCl(1 0 0) surface.