Sexithiophene films on cleaved KBr(1 0 0) towards well-ordered semiconducting films

The morphology and possible molecular orientation of sexithiophene thin films on cleaved KBr(1 0 0) under different epitaxial growth rate are investigated by atomic force microscopy. It is found that both the surface morphology and the molecular orientation are strongly related to the epitaxial growth rate; the controlled domains exist as flat-topped domains and grow at a three-dimensional growth mode. The maximum domain size of 30 μm × 30 μm flat-topped domain is obtained; the surface cracks significantly decreases with the decrease of epitaxial growth rate.