Fluorene Derivatives for Efficient Prompt Scintillation in Plastic Scintillators

Plastic scintillators have been investigated for γ-ray detection with the promise of fast response, ease of scale up, and mechanical toughness. However, their low light yield has been a major limiting factor in the performance metrics. Herein, we report a cross-linkable fluorene derivative, 9,9-bis­(4-vinylbenzyl)-9H-fluorene (SF), copolymerized with the plastic matrix, to facilitate effective Förster resonance energy transfer to boost the light yield. Noncurable 9,9-dimethyl-9H-fluorene (MF) and 9,9′-spirobifluorene (SBF) were also introduced to bridge the energy transfer gap between the polymer matrix and the primary dye. The plastic scintillator comprising 5 wt % SF and 20 wt % MF exhibits a light yield of 11 600 photons/MeV with a scintillation decay time constant of 2.3 ns.