Morphology and orientation of thin poly(3-hexylthiophene) (P3HT) films on differently silanized silicon oxide

The morphology and structure of the overlying poly(3-hexylthiophene) (P3HT) layer onto differently silanized silicon oxide has been studied by Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD) techniques. By increasing the silanizer alkyl chain length, the layer morphology evolves from a filament like to globular needle like as a consequence of the different SAM organization, while the P3HT conformation remains edge-on. For each case the effect of the annealing temperature has been studied. For all the cases a particular attention has been paid to the first thin layers close to the interface P3HT/SiOx. The effect of a polar substituent and presence of aromatic ring has been also studied.