Inorganic X-ray Scintillators Based on a Previously Unnoticed but Intrinsically Advantageous Metal Center

Abstract

Traditional inorganic X-ray scintillators are designed based on several representative metal ions (e.g., Tl+, Pb2+, Bi3+) with highly emissive nature and high atomic number aiming at the outstanding radiation stopping power. The combination of these two features gives rise to a high energy conversion efficiency from X-ray to visible emission, which is a prerequisite for an ideal scintillator and is currently one of the major limits for the further development of this field. Inspired by our recent observation on the intrinsic scintillating phenomenon in the heaviest naturally occurring element uranium, we report here a family of inorganic scintillators through combination of uranyl ions with diverse oxoanion groups (i.e., borate, phosphate, molybdate, germanate, etc.). Na2UO2(MoO4)2·(H2O) (UMO) is selected as a prototype of a uranyl-bearing inorganic scintillator, to show its intrinsic advantages in the X-ray excited luminescence (XEL), strong X-ray attenuation coefficient (XAC), reduced afterglow, and decent radiation stability, as compared with one of the most important commercial inorganic scintillators CsI:Tl.

Multimodal Luminescent Yb3+/Er3+/Bi3+‐Doped Perovskite Single Crystals for X‐ray Detection and Anti‐Counterfeiting

“…[14,15] As for the XEL materials, heavy atoms are the typical selection, which emits the low-energy visible light via a series of complex photo-physical conversion processes. [16,17] In order to achieve the ultimate goal of multimodal luminescent performance, it is necessary to systematically integrate various luminescence properties from combining luminescent materials, RE ions and other metal ions. [18,19] Until now, it is a challenging task to find suitable matrices and elements to successfully actualize such a combination strategy for this multipurpose luminescence.…”

“…A small amount of Bi 3+ doped into RE-1 structure absorbs the high energy from X-ray, which enhances the structure perfection, promotes the exciton localization, and further improves the XEL performance as well as the photoluminescence quantum yield (PLQY). [17,28,36,55] Meanwhile, in order to further study the influence of defect concentrations on the luminescence performance in the same material, we apply varied external pressure on the material systems to create defects in RE-1. The UC PL spectra of RE-1 under different pressures are shown in Figure S13, Supporting Information.…”

“…Therefore, RE-1 present more excellent stability against the humidity than CsI:Tl, and further proved that RE-1 has appreciable application prospect, which could serve as an excellent scintillator to fabricate high performance and longperiod devices for radiation detection. [17,56] The luminescence spectra of RE-1 under different powers of the X-ray anode tube is shown in Figure 3e. With the voltage kept constant (40 kV), the current increased from 15 to 40 mA, the XEL spectra show that the emission intensity of the sample increased gradually.…”

Gleaming Uranium: An Emerging Emitter for Building X‐ray Scintillators

“…Following the organic–inorganic hybrid uranyl‐bearing scintillator, we designed and synthesized a series of uranyl‐bearing inorganic scintillators with the intent of enriching this new scintillator family . It has been proved that the uranyl ion is highly adaptive in various inorganic lattices including uranyl borates, uranyl phosphates, uranyl germanates, and uranyl molybdates.…”

“…Recently, we designed a uranyl‐bearing organic‐inorganic hybrid compound, leading to the first observation of the X‐ray scintillation phenomenon of uranium‐containing materials . Furthermore, we emphasized that uranyl‐bearing inorganic compounds could be a rich platform for developing inorganic scintillating materials with high radiation stopping power and decent radiation resistance . Through the combination of versatile coordination chemistry, intrinsic luminescence, and physical properties, we conceptualize that uranium could be an emerging emitter for building X/gamma‐ray scintillators.…”