Efficient and ultrafast organic scintillators by hot exciton manipulation

Abstract Efficient and fast scintillators are in high demand for 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 faced by almost all scintillators. To overcome this limitation, we have developed a new 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-tetraphenylethylene (4-bromophenyl) (TPE-4Br) shows an ultrafast radiative lifetime of 1.79 ns and ~ 72600 photons MeV − 1 light yield, exhibiting an unprecedented combination of high light yield and short decay time. Our work provides a paradigm-shifting method to design efficient and ultrafast scintillators and paves the way towards exciting applications toward ultrafast detection and imaging.