Semiconducting polymers containing benzodithiophene with decyl phenylethynyl and hexadecyl phenylethynyl substituents have been synthesized by Stille coupling polymerization. The optoelectronic properties of the synthesized polymers have been investigated. The synthesized polymers were tested in bulk heterojunction solar cells.

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Polymers containing a fused benzodithiophene core with phenylethynyl substituents were prepared. The parent poly[4,8-bis(4-pentylphenylethynyl)benzo[1,2-b:4,5-b']dithiophene] was prepared by a Stille coupling. Copolymers with the new core were also obtained by Stille coupling with dibrominated fluorene and carbazole monomers. The obtained polymers had a lower band gap as compared to the related benzodithiophene cores due to the extended electron conjugation. The polymers were also highly fluorescent as observed by high quantum yields.

Poly(3-hexylthiophene)-b-poly(γ-benzyl-L-glutamate) (P3HT-b-PBLG) rod-rod diblock copolymer was synthesized by a ring-opening polymerization of γ-benzyl-L-glutamate-N-carboxyanhydride using a benzylamine-terminated regioregular P3HT macroinitiator. The opto-electronic properties of the diblock copolymer have been investigated. The P3HT precursor and the P3HT-b-PBLG have similar UV-Vis spectra both in solution and solid state, indicating that the presence of PBLG block does not decrease the effective conjugation length of the semiconducting polythiophene segment. The copolymer displays solvatochromic behavior in THF/water mixtures. The morphology of the diblock copolymer depends upon the solvent used for film casting and annealing results in morphological changes for both films deposited from chloroform and trichlorobenzene.

Poly(3‐hexylthiophene)‐block‐poly(2‐ethyl‐2‐oxazoline) amphiphilic rod–coil diblock copolymers have been synthesized by a combination of Grignard metathesis (GRIM) and ring‐opening cationic polymerization. Diblock copolymers containing 5, 15, and 30 mol‐% poly(2‐ethyl‐2‐oxazoline) have been synthesized and characterized. The synthesized rod–coil block copolymers display nanofibrillar morphology where the density of the nanofibrills is dependent on the concentration of the poly(2‐ethyl‐2‐oxazoline) coil segment. The conductivity of the diblock copolymers was lowered from 200 to 35 S · cm−1 with an increase in the content of the insulating poly(2‐ethyl‐2‐oxazoline) block. By contrast, the field‐effect mobility decreased by 2–3 orders of magnitude upon the incorporation of the poly(2‐ethyl‐2‐oxazoline) insulating segment.magnified image