Fused ring oligothiophenes and their derivatives, as active organic semiconductors, are widely used in electronic devices. The influence of molecular conjunction length on reorganization energy, electronic coupling and charge mobility of two fused ring oligothiophenes are investigated theoretically. The charge mobility of 2, 5-di(thiophen-2-yl)thieno [3, 2-b]thiophene (T-T(2)-T) with longer molecular conjunction length is 0.226 cm(2)V(-1)s(-1), which is nearly 3 times larger than that of 2, 2-bithieno[3, 2-b]thiophene (T(2)-T(2)) as 0.085 cm(2)V(-1)s(-1). The investigation will provide a new perspective to design high mobility organic semiconductors.
Keywords: Charge-transfer mobility; Molecular Structures; Oligothiophenes.