New organic semiconductors and their device performance as a function of thiophene orientation

We report a first investigation of two new isomer-pure thieno[f,f′] bis[1]benzothiophenes, i.e. syn and anti with respect to the orientation of the thiophenes along the long axis of the molecule, applied as organic semiconductors in organic field-effect transistors. The field-effect mobility of both regioisomers is substantial and reaches up to 0.12 cm2 V -1 s-1, a value that is at most one order of magnitude lower than the best known organic transistors based on silicon dioxide gate insulators. © The Royal Society of Chemistry 2006.