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Organic/inorganic hybrid structures are promising systems for a variety of functional devices because of their low cost, light weight, and ease of large-scale production. However, the ability to control the morphology to obtain a large interfacial area for hybrid interactions and continuous transportation pathway for enhanced optoelectronic properties is still a critical issue for advanced applications. Here, we report on a facile development of a hydrothermal method at elevated pressure to manufacture P3HT/ZnO nanohybrid thin films comprising in situ synthesized ZnO nanocrystals embossed on structure-directing long-range order P3HT nanofibrils. The in situ hybrid fabrication method first involves chelating zinc acetate on the sulfur atoms in P3HT as the anchoring sites, followed by utilizing the high pressure (∼9 bar) hydrothermal process to synthesize ZnO nanoparticles on P3HT nanofibrils, synergistically resulting in high crystallinity for both materials in nanoscale. This process demonstrated the ability to synthesize highly crystalline monophasic wurtzite-type ZnO nanoparticles in situ on organic polymers at temperatures (≤150 °C) typically below the melting temperature of the organic polymers to preserve their superior crystalline property, compared with an ambient pressure fabrication process in which in situ grown ZnO nanoparticles in the hybrids remained mostly amorphous at 150 °C. In particular, photophysical property analyses showed that the highly crystalline P3HT/ZnO hybrid films exhibited enhanced UV absorption, photoluminescence quenching, and shorter exciton lifetime. This enhancement in the optoelectronic properties indicated that the hybrid possessed intimate contact at D/A interfaces for photogenerated excitons dissociation and provided continuous nanochannels for efficient charge transfer, thus leading to superior performance of optoelectronic properties. We believe that this study paves the way for fabricating highly functional hybrid materials for future optoelectronic applications.

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Upon the dissolution of comb-like polyalkylthiophenes in the melt of a crystalline hexamethylbenzene compound, eutectic molten mixtures were prepared, which were found to involve disparate mixing statuses of polyalkylthiophenes. When more than 2 wt % of polyalkylthiophenes is mixed in molten solutions, metastable face-on lamellae of polyalkylthiophenes widely spread upon efficient eutectic solidification, instead of stable edge-on crystalline lamellae. Beyond a critical concentration of polyalkylthiophene, the association of board-like thiophene backbones into stripe-like micelles in molten solutions was proposed as a preceding background. When the association tendency in molten mixture declines with the decrease of concentration or molecular weight, only edge-on lamellae are precipitated. Furthermore, as indicated by the structural analysis via electron diffraction patterns, the stacking of metastable face-on nanostructures is able to transform to stable edge-on crystals via collaborative rotation and lateral association of thiophene backbones. Nevertheless, with the attachment of a longer side chain, this structural evolution is hindered by enhanced kinetic barriers, and thus regular stacking of face-on nanostructures is able to persist and progress as an alternative organization route. For face-on nanostructures serving as a preordering state prior to the growth of edge-on crystals, annealing temperatures capable of initiating an overall structural transition within thin film have been explored and manifested as an indication of the metastability.