Conjugated polymers have attracted broad attention as semiconducting materials in optoelectronic devices such as organic field-effect transistors (OFETs), light-emitting diodes (OLEDs), and organic photovoltaics (OPVs). Due to their advantages of being solution processable and compatible with flexible substrates, they offer great application potential. In the quest for designing a new polymer donor, the introduction of a thiadiazole unit as an electron-withdrawing group to the backbone of conjugated polymers has attracted significant research interest. As a result a variety of donor (D)-acceptor (A) type of conjugated polymers have been synthesized, a majority of them are based on the 2,1,3- benzothiadiazole (BTz) moiety. BTz-based D-A copolymers have been exploited through substitution of the sulfur atom by oxygen, nitrogen, and selenium, by replacement of the benzene ring with more electron-withdrawing rings such as pyridine and pyridazine. In addition, the introduction of heteroatoms such as fluorine or groups like alkyloxyl side chains have led to interesting developments in the efficiency of OPVs and hole and/or electron mobility of OFETs. Another design strategy to modify BTz based D-A conjugated polymers is through fusion of the benzene ring with other aromatics moieties which can increase planarity and thus π-electron delocalization, π-π stacking, light absorption and charge transportation properties of the resulting copolymers. New acceptor moiety dithienobenzothiadiazole (DT-BTD) were synthesized by fusing BTz with thiophene. Based on DT-BTD two donor-acceptor type of conjugated polymers namely (P1 and P2) were synthesized by using the Stille copolymerization method. The synthesized copolymers were characterized by 1H-NMR, GPC, and elemental analysis. The optical band gaps of the polymers were found to be 1.86 and 1.9 eV, respectively, as calculated from their film onset absorption edge. Upon annealing both produced a distinct shoulder peak in their film absorption spectra. The electrochemical studies of P1 and P2 revealed that the HOMO and LUMO energy levels of the polymer were -5.3, -5.1 eV, and -3.4,
-3.2 eV, respectively. The polymers are thermally stable up to 250-350 oC. The FET characteristics of P1 and P2 copolymers were studied using a bottom-gate, top-contact thin-film transistor devices. The devices were built on a self-assembled monolayer OTS-18 modified silicon wafer substrate using the spin-coated D-A copolymer as the channel semiconductor. The fabrication and characterization of OFET devices were performed under ambient conditions. The evaluation showed that both P1 and P2 copolymers behaved as p-type semiconductors in their respective OFET devices with hole mobility of 0.024 cm2V-1s-1 and 0.026 cm2V-1s-1 respectively after thermally annealed at 120 oC. The current on/off ratio for these devices were around 105. Based on these measurements, it was shown that DT-BTD could be a potential building block for the synthesis of D-A conjugated polymers for different types of organic electronics applications.