Surfactant-Dependent Bulk Scale Mechanochemical Synthesis of CsPbBr₃ Nanocrystals for Plastic Scintillator-Based X-ray Imaging

Abstract

We report a facile, solvent-free surfactant-dependent mechanochemical synthesis of highly luminescent CsPbBr 3 nanocrystals (NCs) and study their scintillation properties. A small amount of surfactant oleylamine (OAM) plays an important role in the two-step ball milling method to control the size and emission properties of the NCs. The solid-state synthesized perovskite NCs exhibit a high photoluminescence quantum yield (PLQY) of up to 88% with excellent stability. CsPbBr 3 NCs capped with different amounts of surfactant were dispersed in toluene and mixed with polymethyl methacrylate (PMMA) polymer and cast into scintillator discs. With increasing concentration of OAM during synthesis, the PL yield of CsPbBr 3 /PMMA nanocomposite was increased, which is attributed to reduced NC aggregation and PL quenching. We also varied the perovskite loading concentration in the nanocomposite and studied the resulting emission properties. The most intense PL emission was observed from the 2% perovskite-loaded disc, while the 10% loaded disc exhibited the highest radioluminescence (RL) emission from 50 kV X-rays. The strong RL yield may be attributed to the deep penetration of X-rays into the composite, combined with the large interaction cross-section of the X-rays with the high-Z atoms within the NCs. The nanocomposite disc shows an intense RL emission peak centered at 536 nm and a fast RL decay time of 29.4 ns. Further, we have demonstrated the X-ray imaging performance of a 10% CsPbBr 3 NC-loaded nanocomposite disc.

Large-area in situ growth of a flexible perovskite scintillator film for X-ray indirect detection applications

“…Metal halide perovskite (MHP) scintillators have broad application prospects in the field of X-ray detection and imaging relying on their strong X-ray absorption capacity, short radioluminescence decay time and large-scale preparation. 5–7 At present, the light yield and X-ray spatial imaging resolution of MHP scintillators have reached 91 056 photons per MeV and 104.3 lp mm −1 by self-assembly and dual-solvent evaporation technology, respectively. 8–10 The MHP scintillators include single crystals and polycrystalline films.…”

Turning Nonemissive CsPb2Br5 Crystals into High-Performance Scintillators through Alkali Metal Doping

“…We further demonstrated the use of the CsPb 2 Br 5 :K scintillator for X-ray imaging. X-ray imaging with high contrast and fine spatial resolution is crucial to revolutionize medical diagnostics, nondestructive testing, and security screening. − The high contrast and fine resolution are highly dependent on the penetrability of radioluminescence along the scintillation screen, which is mainly limited by radioluminescence intensity and self-absorption. Benefiting from the high radioluminescence intensity and non-self-absorption, CsPb 2 Br 5 scintillators hold great promise for high-quality X-ray imaging compared with CsPbBr 3 microcrystal scintillators with severe self-absorption (Supplementary Figure 21).…”