Synergistic in Situ Hybrid Synthesis of Highly Crystalline P3HT/ZnO Nanowires at Elevated Pressures

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.