The high dielectric constant and versatile ferroelectric properties of poly(vinylidene fluoride) (PVDF) and its copolymers, poly[(vinylidene fluoride-co-trifluoro ethylene] [P(VDF−TrFE)] and poly[(vinylidene fluoride−co−trifluoro ethylene−co−chlorotrifluoro ethylene)] [P(VDF−TrFE−CTFE)], are widely exploited in sensors, tissue engineering, energy storage, and beyond. However, their use in fields such as micro−/optoelectronics is limited due to their insulating properties. Contrarily, organic semiconductors, which are prevalent in electronic applications, are in many instances, limited in efficiency owing to their low dielectric constants. Blending of these low−k:high−k polymers by solution processing, has the potential to combine these rare set of functionalities (i.e. ferroelectricity and semiconductivity), provided that we can gain control of the microstructure and phase morphology of such blends and, hence, their resulting macroscopic characteristics. Here, work is presented on model systems based on the quintessential semiconducting polymer poly(3−hexylthiophene) (P3HT) and the high efficiency organic solar cell material poly[(5,6−difluoro−2,1,3−benzothiadiazol−4,7−diyl)−alt−(3,3’’’−di(2−octyldodecyl)−2,2’,5’,2’’,5’’,2’’’−quaterthiophen−5,5’’’−diyl)] (PffBT4T−2OD), blended with PVDF/copolymers. We will discuss how the blend’s structural features including degree of crystallinity/vitrification, texture, domain size, intermixing vs. phase separation can be manipulated via the blend composition, molecular weight, as well as kinetic and thermodynamic processes. A correlation between structure, dielectrics and semiconducting features (including charge dynamics) is presented, that helps to deliver a detailed picture of the optoelectronic landscape of polymer semiconductors in such high−k surroundings. Furthermore, insights on the overall physico−chemical properties of such systems will be discussed for designing new material systems that satisfy not only existing needs but also open up new applications with the benefit of not having to design all requirements into one material.

Structural and optoelectronic landscape of semiconductor:ferroelectric blends

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.