Organic Thin Film Transistors from a Soluble Oligothiophene Derivative Containing Thermally Removable Solubilizing Groups

A symmetrical alpha,omega-substituted sexithiophene derivative containing thermally removable branched ester solubilizing groups has been prepared. These oligomers can be solution cast into thin films and then thermolyzed to remove the solubilizing group, leaving short pendant alkene groups on the oligomer. Device testing of thin film transistors shows an increase in hole mobility from 1 x 10-5 cm2/(V s) with on/off ratios of approximately 100 before thermolysis to 5 x 10-2 cm2/(V s) with on/off ratios >105 after thermolysis. This method offers an attractive route to easily processed and highly performing thiophene oligomers.