Minimizing lateral domain collapse in etched poly(3-hexylthiophene)-block-polylactide thin films for improved...

Thin films of poly(3-hexylthiophene)-block-polylactide block copolymer exhibiting ordered lamellar morphology have been selectively etched to produce structured films that could be used in fabrication of idealized bulk heterojunctions for organic or hybrid solar energy devices. Etched poly(3-hexylthiophene) films, after being rinsed in water to remove degraded polylactide fragments, were dried using various drying approaches that reduce or alleviate surface tension forces generated during liquid evaporation from the film. As emphasized by atomic force microscopy, X-ray diffraction, and emission photoluminescence, a reduction in domain collapse leads to improved molecular ordering in the plane perpendicular to the substrate and enhanced photoluminescence quenching when paired with fullerene C(60) hydroxide electron acceptors.