The Nanoplasmonic Purcell Effect in Ultrafast and High-Light-Yield Perovskite Scintillators

Abstract: The development of X-ray scintillators with ultrahigh light yields and ultrafast response times is a long sought-after goal. In this work, we theoretically predict and experimentally demonstrate a fundamental mechanism that pushes the frontiers of ultrafast X-ray scintillator performance: the use of nanoscale-confined surface plasmon polariton modes to tailor the scintillator response time via the Purcell effect. By incorporating nanoplasmonic materials in scintillator devices, this work predicts over 10-fold enhancement in decay rate and 38% reduction in time resolution even with only a simple planar design. We experimentally demonstrate the nanoplasmonic Purcell effect using perovskite scintillators, enhancing the light yield by over 120% to 88 $\pm$ 11 ph/keV, and the decay rate by over 60% to 2.0 $\pm$ 0.2 ns for the average decay time, and 0.7 $\pm$ 0.1 ns for the ultrafast decay component, in good agreement with the predictions of our theoretical framework. We perform proof-of-concept X-ray imaging experiments using nanoplasmonic scintillators, demonstrating 182% enhancement in the modulation transfer function at 4 line pairs per millimeter spatial frequency. This work highlights the enormous potential of nanoplasmonics in optimizing ultrafast scintillator devices for applications including time-of-flight X-ray imaging and photon-counting computed tomography.