UV-to-NIR Wavelength Conversion of π-Conjugated Polymers Based on Pyrene-Substituted Boron-Fused Azobenzene Complexes
Masashi Nakamura, Momona Yamauchi, Masayuki Gon, Kazuo Tanaka
Abstract
Luminescent molecules with large Stokes shifts are useful in various fields such as wavelength converting materials (WCMs). However, there have been few reports of WCMs capable of converting ultraviolet (UV) light into near-infrared (NIR) one. In this study, by introducing pyrene into π-conjugated polymers with NIR emissive polymers, we have achieved highly efficient UV-to-NIR wavelength conversion through almost quantitative intramolecular energy transfer in both solution and film. The intensity of the NIR fluorescence derived from the polymer main chain can be enhanced by the superior UV-absorption property of the pyrene. In addition, the luminescence property can be tuned depending on the substitution position of the pyrene due to steric repulsion with the main chain.