Deterministic Light Yield, Fast Scintillation, and Microcolumn Structures in Lead Halide Perovskite Nanocrystals

Abstract

Lead halide perovskite (LHP) nanocrystals (NCs) have recently attracted attention due to both their high quantum yield and their potential for X-ray imaging applications. In this paper, we investigated the scintillation properties of three different LHP NCs; CsPbBr 3 , FAPbBr 3 , and CsPbI 3 . The featured NCs exhibited high X-ray excited luminescence (XL) at cryogenic temperatures. While FAPbBr 3 and CsPbI 3 NCs display thermal quenching, CsPbBr 3 NCs show negative thermal quenching and high XL at high temperatures, with a light yield of 24,000 ± 2,100 photons/MeV at 300 K. The LHP NCs exhibit a small afterglow and low trap density and exhibit a very fast XL decay time, under 20 ns, faster than those of some currently used commercial scintillators. Overall, CsPbBr 3 NCs are the best performing materials investigated here, making them particularly attractive for fast-timing applications such as positron emission tomography or particle detectors in high-energy physics. In the end, we demonstrate the proof of concept for using a CsPbBr 3 NC matrix for imaging applications and the flexibility of NCs for developing microstructure scintillators.

Scintillation Response Enhancement in Nanocrystalline Lead Halide Perovskite Thin Films on Scintillating Wafers

“…Moreover, in contrast with, e.g., CsPbBr 3 single crystals [ 11 ], CsPbBr 3 nanocrystals show negative thermal quenching (increase of radioluminescence intensity with increasing temperature) leading to scintillation light yield of 24,000 ± 2100 MeV −1 at 300 K under 662 keV excitation, which is one order of magnitude higher than other nanocrystals in this family, namely FAPbBr 3 and CsPbI 3 [ 15 ].…”

Formamidinium Lead Halide Perovskite Nanocomposite Scintillators

“…These nanocrystals exhibit fast lifetimes and bright emission with tunable wavelength between 403 and 531 nm. The scintillation properties of FAPbBr 3 have previously been reported only for colloidal nanocrystals [14] and for thin films of nanocrystals [34], while here, we produced nanocomposite scintillators consisting of green-emitting FAPbBr 3 nanocrystals within either an EJ-290 plastic scintillator matrix or a PMMA matrix and demonstrate an improvement in transparency via surface modification using BMEP. The nanocomposite scintillators (particularly those with a PMMA matrix) show brighter luminescence than EJ-290 plastic scintillator alone; those with an EJ-290 matrix show faster lifetimes than FAPbBr 3 nanocrystals encapsulated in PMMA.…”

Stable and Bright Commercial CsPbBr3 Quantum Dot-Resin Layers for Apparent X-ray Imaging Screen

“…Lead halide perovskite quantum dots (LHP-QDs) and nanocrystals (NCs) have been shown to have remarkable properties as scintillators. − LHP-QDs and NCs share generally the same attractive features of three-dimensional crystalline perovskite halides, − such as simple and fast crystal growth, intense emission intensities under high-energy excitation, corresponding to relatively high light yields, small afterglow effects, short attenuation length, and fast X-ray excited luminescence (XL) decay. ,,,, With the quantum confinement effects, , QDs and NCs exhibit high quantum yields , and engineerable band gap. Another advantage of LHP-QDs and NCs is the low temperature ( T < 200 °C) solution-process synthesis as opposed to expensive techniques such as high-vacuum technology for conventional crystalline scintillators on the market.…”

“…This makes LHP-QDs and NCs potentially both cheaper and more environmentally friendly to produce. Cesium lead bromide QDs (CsPbBr 3 -QDs) and NCs, in particular, have recently demonstrated very promising scintillating properties, such as high light yields up to 25 000 photons/MeV at room temperature and to be excellent candidates for X-ray imaging applications. − ,, However, LHP-QDs and NCs have the disadvantage of being (1) very sensitive to atmospheric moisture, , which can lead to their degradation, and (2) difficult to obtain thick enough films for efficient X-ray absorption and thus scintillation.…”

“…In this work, we incorporated commercial CsPbBr 3 -QDs within a resin matrix and laminated the active film between two transparent resin layers to not only protect the CsPbBr 3 -QDs from degradation due to moisture but also make thick films (>100 μm) possible to obtain for imaging applications, compared to previously reported works in the literature. , We proceed to examine the emission and scintillation properties and X-ray imaging capabilities of CsPbBr 3 -QDs at different concentrations within the resin matrix. We first measure the samples’ photoluminescence (PL) properties, including excitation and emission spectra and time-resolved PL (TRPL) decay.…”