Efficient and ultrafast organic scintillators by hot exciton manipulation

Efficient and fast scintillators are in high demand in a variety of fields, such as medical diagnostics, scientific instruments and high-energy physics. However, the trade-off between high scintillation efficiency and fast timing properties is a common challenge facing almost all scintillators. To overcome this limitation, we have developed a strategy for organic scintillators by directing all hot excitons into fast singlet emission states without involving the lowest triplet states. Our scintillator, 1,1,2,2-tetrakis(4-bromophenyl)ethylene, shows an ultrafast radiative lifetime of 1.79 ns and a light yield of ∼34,600 photons per MeV, exhibiting an excellent combination of high light yield and short decay time. Our work provides a method to design efficient and ultrafast scintillators, and paves the way towards exciting applications for ultrafast detection and imaging. Researchers overcome the typical scintillator trade-off between high efficiency and speed. In organic scintillators, researchers drove hot excitons into fast singlet emission states without involving the lowest triplet states, which led to a fast radiative lifetime and strong light yield that may be applicable to ultrafast detection and imaging.