Organic semiconductors based on annelated β-oligothiophenes and its application for organic field-effect transistors

Abstract

Organic field-effect transistors based on two derivatives of annelated β-oligothiophenes are fabricated. High mobility of 2.2 cm² V⁻¹ s⁻¹ is obtained for 2,5-distyryl-dithieno[2,3-b:3′,2′-d]thiophene (DEP-DTT) while 2,5-diphenyl-dithieno[2,3-b:3′,2′-d]thiophene (DP-DTT) presents no field-effect characteristics. The existence of S–π intermolecular interaction in DEP-DTT, which is introduced by CC double bonds, plays an important role in the molecular arrangement both in single crystal and thin film structures, and the charge transport of organic field-effect transistors.