Liquid and film-type organic scintillators based on near-infrared fluorescent π-conjugated polymers containing hypervalent tin(IV) compounds

Abstract

Much effort has been devoted to developing organic scintillators because of their wide versatility in the liquid and solid states. Recently, near-infrared (NIR) scintillators have attracted much attention owing to their ability to sensitively detect radiation doses. Herein, we report that NIR fluorescent π-conjugated polymers containing hypervalent tin(IV) compounds can be utilized for generating liquid and film-type organic scintillators. By incorporating tin, a heavy element known to have excellent radiation absorption properties, into the fluorescent π-conjugated framework, intense scintillations were observed upon X-ray irradiation. The polymer films exhibited NIR fluorescence in the region from 700 to 1250 nm, and the scintillation signals were enhanced as the irradiation dose increased. These results demonstrate that incorporating heavy elements into π-conjugated skeletons is an effective strategy to fabricate organic scintillators based on luminescent polymers. The performances of liquid and film-type NIR scintillation detectors based on π-conjugated polymers containing hypervalent tin(IV) compounds are evaluated. Taking advantage of the high radiation absorption of tin (Sn) and highly efficient NIR fluorescence from the π-conjugated polymers in both solution and on a film, the polymers can be used as both liquid and film-type NIR scintillators. Moreover, the radioluminescence showed good linearity across the dose rate range of 50 to 5000 mGy h−1, suggesting their practical use as NIR scintillation detectors.