Main chain conjugated linear polymers, constituted by alternating electron-donor (D) and -acceptor (A) moieties, have been prepared with the aim of testing their performances as photoactive components in single material organic solar cells (SMOSCs). The D moiety is constituted by bithiophene co-units bearing in position 3 of the thiophene ring a hexyloxy, a hexyloxymethyl or a hexyl group, while the A moiety is represented by the benzothiadiazole group. The D–A polymers were obtained in high yield through the poorly demanding oxidative FeCl3 polymerization process – starting, respectively, from the related precursors 4,7-bis(3-hexyloxythiophen-2-yl)benzo[c][2,1,3]thiadiazole, 4,7-bis[3-(6-methoxyhexyl)thiophen-2-yl]benzo[c][2,1,3]thiadiazole and 4,7-bis(3-hexylthiophen-2-yl)benzo[c][2,1,3]thiadiazole – with low dispersity indexes, close to the monodisperse state, after fractionation with methanol. The …