Synthesis and Self-Assembly of Donor–Acceptor–Donor Based Oligothiophenes and Their Optoelectronic Properties

In this work, the synthesis of an oligothiophene having a donor–acceptor–donor (D–A–D) chromophore with hydrogen bonding groups is described. The D–A–D molecule was demonstrated to self-organize via intermolecular H-bonding between barbituric acid units. Interactions between the oligothiophene subunits were also found to be important, affording nanoribbons that could be observed by atomic force and transmission electron microscopy. The applicability of the oligothiophene for organic electronic applications was investigated by fabricating organic field-effect transistors (OFETs) and organic photovoltaic devices. The OFET measurements yielded p-type mobility of 7 × 10–7 cm2/(V s), and when blended with C60-PCBM, the photovoltaic efficiency was observed to be 0.18%.