| 研究実績の概要 |
With inherent solid-state structural (crystalline/amorphous) complexity in polymer-based condensed-phase materials, the current understanding on photoinduced exciton/carrier dynamics and exciton/carrier transport over interfaces is limited. To overcome this hurdle, we have achieved facile synthesis of conjugated polymer particles (CPPs) whose internal structure features pure crystalline domains. We performed structural characterization on CPPs obtained from regioregular poly(3-hexylthiophene) (rr-P3HT), using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and these results confirm their highly pure crystallinity that extends over 100s of nm. Even after solvent evaporation, therefore no additional molecular packing within crystalline domains is observed from the UV-vis spectroscopy. This opens new opportunities to investigate exciton/carrier dynamics only within a pure crystalline domain or at the interface between only crystalline and electron acceptors.
Additionally, in our effort to understand structure-property relations in organic-based materials, we utilized metal-organic frameworks (MOFs) featuring pyrene as an organic photoactive unit. In the excited-state studies of two MOFs (NU-901 and NU-1000), which are chemically identical (Zr6(μ3-O)4(μ3-OH)4(-OH2)4(TBAPy)2), while topologically distinguished, we showed that due to the topological difference, NU-901 contrastingly forms excimer to NU-1000. This study demonstrates that the topological control can modulate the fate of excited-states.
|
