Structure property relationships of benzo[b]thiophen/benzo[b]furan end-capped naphthalene oligomers and their application for organic field effect transistors

A series of new naphthalene oligomers were designed and synthesized through linking at the α- and β-position of the terminal substituents. Optical and electrochemical measurements and DFT simulation revealed the distinctly different electronic structure of the α-position and β-position linked oligomers. The naphthalene oligomer linked at the α-position of benzothiophene exhibits excellent field-effect performances, with mobility as high as 0.13 cm2 V−1 s−1 and on/off ratio over 106. The significant difference of the OFET performances and thin film microstructures between the naphthalene oligomers also confirmed that the substituted position has an important effect on the properties of semiconductor materials and the α-position linked oligomer is better than β-position linked isomers.