Ultrafast Superradiant Scintillation from Weakly Confined CsPbBr3 Nanocrystals

TL;DR

This paper demonstrates that weakly confined CsPbBr3 nanocrystals exhibit superradiant scintillation with ultrafast response and high light yield at cryogenic temperatures, advancing radiation detection and time-of-flight technologies.

Contribution

It introduces the use of giant oscillator strength in perovskite nanocrystals to achieve superradiant, ultrafast scintillation with high efficiency, a novel approach in radiation detection materials.

Findings

Ultrafast scintillation with 420 ps lifetime achieved.

High light yield of approximately 10,000 photons/MeV.

Light transport remains unaffected by GOS accumulation.

Abstract

Efficiency and emission rate are two traditionally conflicting parameters in radiation detection, and achieving their simultaneous maximization could significantly advance ultrafast time-of-flight (ToF) technologies. In this study, we demonstrate that this goal is attainable by harnessing the giant oscillator strength (GOS) inherent to weakly confined perovskite nanocrystals, which enables superradiant scintillation under mildly cryogenic conditions that align seamlessly with ToF technologies. We show that the radiative acceleration due to GOS encompasses both single and multiple exciton dynamics arising from ionizing interactions, further enhanced by suppressed non-radiative losses and Auger recombination at 80 K. The outcome is ultrafast scintillation with 420 ps lifetime and light yield of ~10'000 photons/MeV for diluted NC solutions, all without non-radiative losses. Temperature-dependent light-guiding experiments on test-bed nanocomposite scintillators finally indicate that the light-transport capability remains unaffected by the accumulation of band-edge oscillator strength due to GOS. These findings suggest a promising pathway toward developing ultrafast nanotech scintillators with optimized light output and timing performance.