Organic thin-film transistors based on anthracene oligomers

Organic thin-film transistors (OTFTs)—with an active layer based on the organic semiconducting anthracene oligomers, 2,2′-bianthracene (2A), 2,6-trianthracene (3A), and their dihexyl derivatives (DH-2A and DH-3A)—were fabricated. It was found that thin films of anthracene oligomers deposited by thermal evaporation had lamellar structures with a high degree of molecular ordering. Consequently, the OTFTs based on anthracene oligomers showed high field-effect mobilities. The mobility of the OTFTs was increased by the oligomerization and the substitution of alkyl groups. DH-2A on a SiO2/Si substrate showed the highest mobility of 0.13 cm2/V s. It was also found that the electrical characteristics of the OTFTs were improved by using a Ta2O5 gate insulator.