Warm-White Light Emission of Lead-free CsAg2I3 Single Crystal Scintillator with a One-Dimensional Electronic Structure.

Abstract

Presently, the exploration of novel inorganic lead-free perovskite scintillators has emerged as a prominent topic in the field of perovskite materials. Extensive attention has been garnered by materials such as Cs₃Cu₂I₅ due to their notable advantage in scintillation intensity, but the response time constants in the microsecond or even millisecond range severely constrain their potential applications in scintillators. In this study, large-sized (5-6 mm) CsAg₂I₃ single crystals with an ultrafast warm-white light emission on a nanosecond time scale are presented. Specifically, upon X-ray excitation, the single crystal demonstrates a broad-spectrum white light emission with a color temperature as high as 5129 K, attributed to its self-trapped exciton emission. The ¹³⁷Cs energy spectrum reveals that CsAg₂I₃ possesses an ultrafast response for γ rays with a time constant of 15 ns, which is significantly faster than that of Cs₃Cu₂I₅. Furthermore, time-resolved photoluminescence unveils a subnanosecond component with a response time of 0.9 ns. The characteristics of ultrafast warm-white light emission exhibit the significant potential of CsAg₂I₃ in radiation scintillation detection and its probability of playing a pivotal role in future radiation detection technology.