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Vacuum‐evaporated metal halides (MHs) scintillator thick films have received much attention in the X‐ray imaging field due to their excellent light yield and uniform large‐area preparation. However, the inevitable heteromorphic homologs in MHs (e.g., Copper‐based MHs (Cu‐MHs): CsCu2X3∖Cs3Cu2X5) and change of film structural backbone will result in spectral hybridization (phase purity), and the film eventually detaches (lattice mismatches). Herein, a single‐source vacuum evaporation method to prepare a thick film (≈10 µm) of Cu‐MHs (as an example) scintillators is realized: 1) Presynthesis of pure phase materials by solution method with a protective agent to ensure phase purity without precise control of component ratios in evaporation process; 2) One‐shot formation of film structural backbone avoids stress accumulation and utilize the longitudinal growth characteristics of crystalline films to obtain crystal orientations with better optical outputs. Finally, the films obtained have a light yield comparable to a partially single‐crystal (53 983 photons MeV−1) and an imaging resolution (14.1 lp mm−1) comparable to the partial template method. The detection system based on the prepared Cu‐MHs scintillator thick films exhibits good response speed and linearity in response to different X‐ray radiation intensities and exposure times. The method will further drive the application of MHs is believed. [ABSTRACT FROM AUTHOR]

Organic thermally activated delayed fluorescent (TADF) scintillators hold promising potential for applications in medical radiography and security detection, but the poor X‐ray absorption ability and inferior radioluminescence (RL) hampered their progression. Herein, the study has pioneered the development of high‐performance TADF Ag(I)‐based scintillators from M2X2(dppb)2 (M = Ag, Cu; X = Cl, Br, I) complexes with 1,2‐Bis(diphenylphosphino)benzene (dppb) ligand. In comparison with Cu(I) complexes, the Ag(I) series generally exhibited superior scintillation performance. Notably, Ag2Cl2(dppb)2 (Ag1) stands out with exceptionally high RL intensity (≈125% higher than that of CsI:Tl) and a low detection limit of 59.8 nGy s−1. The outstanding scintillation performance of Ag1 is primarily attributed to the synergistic effect of the high exciton utilization efficiency origin from a small singlet‐triplet energy gap, enhanced X‐ray absorption capacity by heavy atoms, and the high photoluminescence quantum yield (76.47% in ambient atmosphere). By fabricating a flexible film constructed with Ag1 submicron crystalline powders, a high spatial resolution of 25.0 lp mm−1 for X‐ray imaging is obtained. It offers new opportunities for utilizing TADF metal–organic complexes for highly efficient X‐ray scintillation and imaging. [ABSTRACT FROM AUTHOR]

Copper halides, a new class of attractive and potential scintillators, have attracted tremendous attention in X‐ray imaging. However, the ambiguity surrounding their exciton properties and the unclear effect of crystal structure on their photophysical performance hinder an in‐depth understanding of their luminescence mechanism and their further application in the X‐ray imaging field. Herein, copper halide scintillators Cs3Cu2X5 (X = I, Br, and Cl) with a 0D crystal structure is prepared, and their photophysical properties and luminescence mechanism are revealed using both theoretical calculation and experimental verification. The small exciton Bohr diameter together with the high exciton binding energy can cause Cs3Cu2X5 to hold strongly confined excitons and lack quantum‐size effects. The 0D Cs3Cu2X5 materials exhibit a structural framework with a soft crystal lattice and Frenkel excitons with strong confinement effects, further resulting in a luminescence mechanism with self‐trapped excitons. In particular, Cs3Cu2I5 is demonstrated as an efficient scintillator with high radioluminescence efficiency and high spatial resolution of ≈106 µm in radiography, which is primarily attributed to strongly confined excitons to improve the radiative recombination probability of electron‐hole pairs. Overall, this work provides a pathway for developing 0D scintillators with strongly confined excitons to improve X‐ray imaging performance. [ABSTRACT FROM AUTHOR]

Lead‐free metal halides have recently received sustained attention because of their nontoxicity, low‐cost, as well as excellent stability and optoelectronic properties. However, most of the reported lead‐free metal halides are synthesized via slow solution‐processing at high temperature in toxic solvents, which may impede their commercial applications. Here, a solvent‐free strategy is proposed to synthesize inorganic rubidium copper halides (Rb2CuX3, X = Cl, Br) at room temperature, which exhibit efficient violet emission dominated by a self‐trapped excitons (STEs) mechanism and attractive stabilities against ultraviolet illumination and heating. Thus, Rb2CuX3 powders are employed as emitters and scintillators applied in wireless light communication and X‐ray imaging technologies. Under orthogonal frequency division multiplexing modulation, emitters demonstrate a broad −3 dB bandwidth of 26.3 MHz and a high received data rate of 205.1 Mbps. Additionally, flexible scintillation films based on as‐prepared powders are fabricated and show outstanding X‐ray scintillation properties, including a high spatial resolution of 18.1 lp mm−1 and a low detection limit of 104 nGyair s−1, as well as promising imaging performance for irregular objects. These results suggest large‐scale production of nontoxic Rb2CuX3 and their potential commercialization in fields of high‐speed light communication and X‐ray radiography. [ABSTRACT FROM AUTHOR]

Fast neutron and X‐ray imaging are considered complementary nondestructive detection technologies. However, due to their opposite cross‐sections, development of a scintillator that is sensitive to both fast neutrons and X‐rays within a single‐material framework remains challenging. Herein, an organic–inorganic hybrid perovskite (C4H9NH3)2PbBr4 (BPB) is demonstrated as a scintillator that fully meets the requirements for both fast neutron and X‐ray detection. The hydrogen‐rich organic component acts as a fast neutron converter and produces detectable recoil protons. The heavy atom‐rich inorganic fraction efficiently deposits the energy of charged recoil protons and directly provides a large X‐ray cross‐section. Due to the synergy of these organic and inorganic components, the BPB scintillator exhibits high light yields (86% of the brightness of a commercial ZnS (Ag)/6LiF scintillator for fast neutrons; 22 000 photons per MeV for X‐rays) and fast response times (τdecay = 10.3 ns). More importantly, energy‐selective fast neutron and X‐ray imaging are also demonstrated, with high resolutions of ≈1 lp mm−1 for fast neutrons and 17.3 lp mm−1 for X‐rays; these are among the highest resolution levels for 2D perovskite scintillators. This study highlights the potential of 2D perovskite materials for use in combined fast neutron and X‐ray imaging applications. [ABSTRACT FROM AUTHOR]

Scintillators with high light yield, low detection limit, large X‐ray attenuation efficiency as well as stable and nontoxic compositions are of great importance for radiation detection applications. Here, 0D (C8H20N)2Cu2Br4 single crystals are obtained and show blue emission peaking at 468 nm with a near‐unity photoluminescence quantum yield of 99.7%, a large Stokes shift of 148 nm (i.e., negligible self‐absorption), and a good environmental stability along with strong X‐ray absorption capability. Moreover, a high light yield of up to ≈ 91 300 photons/MeV and a low detection limit of 52.1 nGyair s−1 are realized, which is more than one hundred times lower than the dose rate of 5.5 µGyair s−1 required for X‐ray medical diagnostics. (C8H20N)2Cu2Br4 ceramic wafer scintillation screen is fabricated by a cold pressing sintering process, and the clear contrast images of opaque metal box and electronic component with a spatial resolution of 9.54 lp mm−1 are realized. This study not only designs a new lead‐free metal halide scintillator, but also develops a universal strategy for the preparation of large‐sized scintillator screen in nondestructive X‐ray imaging. [ABSTRACT FROM AUTHOR]

Scintillators with high light yield, low detection limit, large X‐ray attenuation efficiency as well as stable and nontoxic compositions are of great importance for radiation detection applications. Here, 0D (C8H20N)2Cu2Br4 single crystals are obtained and show blue emission peaking at 468 nm with a near‐unity photoluminescence quantum yield of 99.7%, a large Stokes shift of 148 nm (i.e., negligible self‐absorption), and a good environmental stability along with strong X‐ray absorption capability. Moreover, a high light yield of up to ≈ 91 300 photons/MeV and a low detection limit of 52.1 nGyair s−1 are realized, which is more than one hundred times lower than the dose rate of 5.5 µGyair s−1 required for X‐ray medical diagnostics. (C8H20N)2Cu2Br4 ceramic wafer scintillation screen is fabricated by a cold pressing sintering process, and the clear contrast images of opaque metal box and electronic component with a spatial resolution of 9.54 lp mm−1 are realized. This study not only designs a new lead‐free metal halide scintillator, but also develops a universal strategy for the preparation of large‐sized scintillator screen in nondestructive X‐ray imaging. [ABSTRACT FROM AUTHOR]

Halide perovskites are an emerging scintillator material for X‐ray imaging. High‐quality X‐ray imaging generally requires high spatial resolution and long operation lifetime, especially for targeted objects with irregular shapes. Herein, a perovskite "polymer–ceramics" scintillator, in which the halide perovskite nanocrystals are grown inside a pre‐solidified polymer structure with high viscosity (6 × 1012 cP), is designed to construct flexible and refreshable X‐ray imaging. A nucleation inhibition strategy is proposed to prevent the agglomeration and Ostwald ripening of perovskite crystals during the subsequent precipitation process, enabling a high‐quality polymer–ceramics scintillator with high transparency. This scintillator‐based detector achieves a detection limit of 120 nGy s–1 and a spatial resolution of 12.5 lp mm–1. Interestingly, due to the anchoring effect of the exfoliated atoms provided by the polymer matrix, the scintillator film can be refreshed after a long duration (≥3 h) and high dose (8 mGy s–1) irradiation. More importantly, this inherent characteristic overcomes the long operation lifetime issue of perovskites‐based scintillators. Hence, the authors' exploration of the polymer–ceramics scintillator paves the way for the development of flexible and durable perovskite scintillators that can be produced at a low operation cost. [ABSTRACT FROM AUTHOR]