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Broadband emissive perovskites are next‐generation materials for solid‐state lighting and radiative detection. However, white‐emitting perovskites are generally synthesized by regulating B/X sites, while not enough attention is paid to the A‐site, which is thought to hardly affect the band‐edge structures and optoelectronic properties. Here, a series of Sb3+‐doped In‐based 0D halide perovskite derivatives are described with various organoammonium cations in A‐sites. Warm‐white light emitting across the visible spectrum (450–850 nm), large Stokes shifts, and high photoluminescence quantum yields are easily tunable by molecularly tailoring A‐site cations. These features enable a light yield up to 60976 Photons/MeV as X‐ray scintillator, and a detection limit of 90 nGyair/s that is ≈60 times lower than the medical requirement. It is proved that A‐site plays a critical role in determining the degree of distortion of polyhedra, which influences the broadband photoluminescence and self‐trapped exciton (STE) dominates the emission process. Moreover, for the first time, via the incorporation of 2,6‐dimethylpiperazine, a mixed A‐site regulating strategy produces a standard white‐light emission, which originates from the blue‐light and yellow‐light related to various STE emission centers. It is foreseen that this strategy highlights the expanded role of A‐site and the importance of rethinking A‐sites in perovskites. [ABSTRACT FROM AUTHOR]

The search for efficient, re-absorption-free scintillators has recently focused the attention on antimony-based halides, which exhibit largely Stokes shifted luminescence due to radiative recombination of excitons self-trapped (STE) in strongly Jahn-Teller distorted Sb3+ color centers. Here, the synthesis of a hybrid structure is reported with chemical formula (C13H14N3)3SbCl6 consisting of spatially isolated [SbCl6]3- octahedra separated by organic N, N'-diphenylguanidinium (Gua) molecules. The optical properties of this material are mainly determined by the inorganic component and are characterized by a pronounced Stokes shift of "1.3 eV and a room-temperature photoluminescence (PL) efficiency of up to 85%. Remarkably, highly efficient radioluminescence (RL) is observed with scintillation light yields of "2000 ph MeV-1 using both soft X-rays and a 124 keV gamma source. Temperature-dependent PL and RL measurements confirm the minor role of non-radiative channels, which are completely suppressed below 100 K. Thermally stimulated luminescence measurements suggest that the traps in Gua3SbCl6 crystals have a significantly large energy depth distribution below the absorbing state. [ABSTRACT FROM AUTHOR]

Copper metal halides have emerged as a strong contender in the scintillator field due to the self‐trapped excitons (STEs) mechanism. However, their development has been hindered by the preparation process. Single crystals have long growth cycles and cannot achieve large areas and flexibility. Quantum dots have a low yield and can easily cause chemical pollution, and the thickness of films prepared by the spin coating cannot be controlled. To address these challenges, a new method for preparing Cs3Cu2Cl5 using sequential vacuum evaporation is developed. This allows successful preparation of large‐area (≈100 cm2) and flexible films. The STEs mechanism of Cs3Cu2Cl5 gives it unique properties such as a large Stokes shift that reduces self‐absorption effects, and a wide full width at half‐maximum that improves coupling with photodiodes. Therefore, Cs3Cu2Cl5 is applied to X‐ray imaging with a light yield of ≈30 000 photons MeV−1, a spatial resolution of over 10 lp mm−1, and a low detection limit below 0.8 µGyair s−1. In addition, the flexible Cs3Cu2Cl5 film enables effective dynamic imaging and clear imaging on non‐planar objects. It also exhibits good resistance to harsh environments, maintaining good imaging performance after 150 days. It is believed that sequential vacuum evaporation provides an important idea for preparing scintillators. [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]

Herein, the first study on the scintillation properties of CsCu2X3 and Cs3Cu2X5 (where X: Cl−, Br−, I−) is presented, describing their charged particle‐induced luminescence involving electrons, protons, α‐particles, and heavy ions, as well as revealing their capabilities on the timing and spectroscopic evaluation of single‐particle events. The thin layers are prepared with a simple and cost‐effective deposition procedure, without the incorporation of external dopants, exploiting the intrinsic radiative recombination observed in low‐dimensional perovskites. The combined effect of the high binding energy and localized stability of self‐trapped excitons, large Stokes shift, defect tolerance, and the high excitation density along the particle track leads to the emergence of boosted scintillation pulses. The observations demonstrate the first use of inorganic thin‐film scintillators with optical pulse characteristics and light yield competitive with doped single crystal scintillators, while also providing improved structural and functional stability under extreme environmental conditions. [ABSTRACT FROM AUTHOR]