Functional Perovskite Hybrid of Polyacetylene Ammonium and Lead Bromide:  Synthesis, Light Emission, and Fluorescence Imagining

A highly photoresponsive perovskite hybrid containing an electroactive organic component (H1) was fabricated. A disubstituted polyacetylene (PA) with a hidden amino functionality (P3) was synthesized, hydrolysis and quaternization of which afforded the desired PA ammonium salt (P5). Mixing P5 with lead bromide readily yielded H1, which was stable, soluble, and film-forming. The inorganic framework induced the polymer chains to align in an ordered fashion, which helped to populate the chain segments with long conjugation lengths. The hybrid emitted a blue light (457 nm) in a high quantum yield (62%), thanks to the enhanced electronic conjugation, the weakened interaction between the layer-segregated chains, and the efficient energy transfer from the inorganic sheets to the organic layers. P3 exhibited a half-discharge time as short as approximately 0.7 s, representing the first example of an efficient photoconductive disubstituted PA. While stable to normal light illumination, H1 was rapidly bleached upon exposure to high-power UV irradiation, enabling facile generation of two-dimensional luminescent photopatterns. After the UV irradiation, the emissions of P9 and P9/H12 were enhanced and weakened, respectively, proving that the inorganic perovskite framework works as a photocatalyst for accelerating the bleaching process of the conjugated PA chains.