High Mobility in Solution-Processed 2,7-Dialkyl-[1]benzothieno[3,2-b][1]benzothiophene-Based Field-Effect Transistors...

A high performing solution-processed field-effect transistors based on 2,7-didodecyl[1]benzothieno[3,2-b][1]benzothiophene (C12-BTBT) has been fabricated by using a simple and straightforward two-step process. We have demonstrated that UV/ozone treatment of the Si/SiO₂ substrates makes it possible to notably enhance the field-effect mobility in spin-coated C12-BTBT based OFETs reaching values as high as 2.7 cm²  V^-1  s^-1 . The influence of this treatment relies essentially on the coverage of the dielectric surface, while the crystalline order remains unaffected. Importantly, the employed method is simple, cheap and easily up-scalable and provides outstanding OFET performances that are comparable to those obtained using expensive and complicated treatments.