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, a fundamental mechanism that pushes the frontiers of ultrafast X‐ray scintillator performance is theoretically predicted and experimentally demonstrated: 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 tenfold enhancement in decay rate and 38% reduction in time resolution even with only a simple planar design. The nanoplasmonic Purcell effect is experimentally demonstrated using perovskite scintillators, enhancing the light yield by over 120% to 88 ± 11 ph/keV, and the decay rate by over 60% to 2.0 ± 0.2 ns for the average decay time, and 0.7 ± 0.1 ns for the ultrafast decay component, in good agreement with the predictions of our theoretical framework. Proof‐of‐concept X‐ray imaging experiments are performed using nanoplasmonic scintillators, demonstrating 182% enhancement in the modulation transfer function at four 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.