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This article describes a new kind of afterglow material, ScBaZn 3 GaO 7 :Bi 3+ , which was synthesized through a high-temperature solid-phase method. Its crystal structure, photoluminescent characteristics, and afterglow characteristics were studied and analyzed. Upon excitation at 344 nm, ScBaZn 3 GaO 7 :Bi 3+ exhibits broadband emission with a central wavelength located at 571 nm (fwhm = 172.98 nm). The sample exhibits an internal quantum efficiency of 65.1%. The bright yellow persistent luminescence of the ScBaZn 3 GaO 7 :Bi 3+ sample was observed after 365 nm irradiation. Thermoluminescence spectroscopy revealed four primary traps within ScBaZn 3 GaO 7 :Bi 3+ , with depths of 0.676, 0.794, 0.882, and 0.972 eV. The traps located at energy levels of 0.676 and 0.794 eV were identified as the key contributors to the sample's afterglow. Finally, the ScBaZn 3 GaO 7 :Bi 3+ sample was combined with a UV-LED chip to fabricate a high-power warm white-light-emitting diode (WLED) device, indicating the potential application prospect of ScBaZn 3 GaO 7 :Bi 3+ phosphor in single-phase warm WLEDs.

Scintillation-based X-ray excited optical luminescence (XEOL) imaging shows great potential applications in the fields of industrial security inspection and medical diagnosis. It is still a great challenge to achieve scintillators simultaneously with low toxicity, high stability, strong XEOL intensity, and weak afterglow as well as simple device processibility with weak light scattering. Herein, we introduce ethylenediaminetetraacetate (EDTA)-capped NaGdF 4 :10Ce/18Tb nanoparticles (NPs) as a highly sensitive nanoscintillator, which meets all of the abovementioned challenges. These NPs show comparable XEOL intensity to the commercial CsI (Tl) single crystal in the green region. We propose a mechanism that involves a new electron-captured path by Ce 3+ ions and the promotion of energy migration from a trap center to surface quenchers via a Gd 3+ sublattice, which greatly reduces the population in traps to produce significant reduction of afterglow. Moreover, by employing an ultrathin transparent NaGdF 4 :10Ce/18Tb film (0.045 mm) as a nanoscintillator screen for XEOL imaging, a high spatial resolution of 18.6 lp mm -1 is realized owing to the greatly limited optical scattering, which is superior to the commercial CsI (TI) scintillator and most reported lead halide perovskites. We demonstrate that doping Ce 3+ ions can greatly limit X-ray-activated afterglow, enabling to use an ultrathin transparent fluoride NP-based nanoscintillator screen for high-quality XEOL imaging of various objects such as an electronics chip and biological tissue.

Metal-organic framework (MOF) glasses are a newly discovered family of melt-quenched glasses. Despite considerable progress in understanding the nature of MOF glasses, their photonic functionalities have not been found so far. Here, we report on the first breakthrough regarding the photonic functionalities of MOF glasses, that is, finding of the luminescence in melt-quenched MOF glasses. The finding was achieved on a zeolitic imidazolate framework (ZIF) series, that is, the ZIF-62 series: Zn 1- x Co x (Im) 1.7 (bIm) 0.3 , x = 0, 0.1, and 0.5, where Co substitutes Zn in ZIF-62 forming single-phased solid solutions. Remarkably, we observed broadband mid-infrared (Mid-IR) luminescence (in the wavelength range of 1.5-4.8 μm) in both the crystalline and amorphous solid solutions. The intensity of the luminescence in ZIF glass is gradually enhanced by increasing the level of Co concentration. The observed Mid-IR emission originates from d-d transition of Co ions. The discovery of the luminescence in ZIF-62 glass may pave the way toward new photonic applications of bulk MOF glasses., Competing Interests: The authors declare no competing financial interest.