Structural Evolution of an Organic Semiconducting Molecule onto a Soft Substrate

• Published in: Chemphyschem 2016-04, Vol.17 (8), p.1174-1179
• Main Authors: Martínez-Tong, Daniel E., Ruzié, Christian, Geerts, Yves H., Sferrazza, Michele
• Format: Article
• Language: English
• Subjects: crystal growth; interfaces; liquid crystals; nanostructures; Sensors; Silicon; thin films
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201501144

The structural organization and evolution of the organic semiconducting molecule 2,7‐dioctyloxy[1]benzothieno[3,2‐b]‐benzothiophene on a soft matrix is studied. Thin films of a blend formed from polystyrene and the molecule were prepared by spin‐coating onto silicon substrates, which were subsequently studied by using a combination of microscopy and scattering techniques. The organic semiconducting molecule segregated to the surface and developed a phase with a different structure to the bulk, as in the case of a substrate induced phase observed previously. Under a solvent vapor annealing procedure, the growth of micrometer‐sized tetragonal crystals onto the polymer surface was observed, which was not evidenced for the silicon substrates. Growing semiconducting crystals: The influence of a soft polymer substrate on the crystalline growth of a [1]benzothieno[3,2‐b]benzothiophene (BTBT) derivative is studied. A crystalline phase, with a structure different from the bulk one, is observed. By treating the samples in a solvent atmosphere, micrometer‐sized tetragonal crystals are grown on the polymer surface.