Flexible and Micropatternable Triplet-Triplet Annihilation Upconversion Thin Films for Photonic Device Integration and Anticounterfeiting Applications.

Triplet-triplet annihilation upconversion (TTA-UC) has recently drawn widespread interest for its capacity to harvest low-energy photons and to broaden the absorption spectra of photonic devices, such as solar cells. Although conceptually promising, effective integration of TTA-UC materials into practical devices has been difficult due to the diffusive and anoxic conditions required in TTA-UC host media. Of the solid-state host materials investigated, rubbery polymers facilitate the highest TTA-UC efficiency.

Blue-shifted aggregation-induced emission of siloles by simple structural modification and their application as nitro explosive chemosensors.

To induce blue-shifted emission of siloles, two tolyl-substituted derivatives - 1,1-diphenyl-2,3,4,5-tetra(m-tolyl)-1H-silole (m-TS) and 1,1-diphenyl-2,3,4,5-tetra(o-tolyl)-1H-silole (o-TS) - were prepared, and their photophysical properties were compared with those of a reference compound, hexaphenylsilole (HPS). By substituting methyl groups at ortho positions of peripheral tetraphenyl rings on the silacyclopentadiene ring, intramolecular rotations could be successfully controlled and the photophysical properties were varied, while substituting methyl groups at meta positions showed similar photophysical properties compared with the case of HPS. That is, simple structural modification at the ortho position significantly affects the geometry and the photophysical properties of silole, which leads to blue-shifted emission.