Spectral modulation and exciton migration in thiophene-based polybenzobisoxazole random copolymers with donor-acceptor architectures

A series of thiophene-based polybenzobisoxazole copolymers (PBO-co-PBOT) with different ratios of thiophene and phenylene moieties were synthesized and characterized. The interplay between morphology and photophysical properties of the copolymers as well as their parent polymers was discussed using wide-angle X-ray diffraction (WAXD), UV-vis absorption, photoluminescence (PL) spectra and time-resolved PL decay dynamics. All the polymers were lyotropic as indicated by the stir opalescence in polycondensation despite the nonlinearity in thiophene-containing polymers. The results show that the PBO and PBOT blend show a much enhanced quantum yield of photophysical processes to indicate efficient interchain energy transfer.