He Feng

In inertial confinement fusion (ICF) experiments, conventional X-ray imaging struggles to achieve high spatial resolution and quantification owing to strong electromagnetic pulses and neutron yields. A novel radioluminescence-based X-ray imaging method is applied in ICF, using Ag-doped phosphate glass (Ag-PG). Ag-PG provides a micron-scale resolution and demonstrates excellent transmission, linearity, and spectral response. In ICF implosion experiments, Ag-PG offers an unprecedented capability to capture the self-emission details of the capsule ablator, enabling precise hohlraum drive symmetry adjustments. This advancement significantly enhances the spatial resolution and quantitative accuracy of ICF X-ray diagnostics.

It is proved that Ag ⁺ is doped into Cs ₃ Cu ₂ Br ₅ lattice through ion doping process, Ag ⁺ doping in Cs ₃ Cu ₂ Br ₅ (5–35%) optimizes at 25%, boosting PLQY from 27.38% to 90.62% and enhancing PL, PLE, and XEL properties.

The influence of Mg doping in α-Al₂O₃ crystals is investigated in this article by first-principles calculations and formation energies, density of states, and computed absorption spectra. Three models related to Mg²⁺ substituting for Al³⁺ doping structures were constructed, as well as spinel structure models with varying aluminum-magnesium ratios. The formation energy calculations confirmed the rationality of the Mg_AlV_O model, which means that Mg substitutional doping incorporating oxygen vacancies is most likely to form in crystals. The combined action of magnesium and oxygen vacancies introduced new defect energy levels in the bandgap. The calculated absorption spectra of the Mg_AlV_O and Mg-rich spinel structures exhibited various color centers. The experimental absorption spectra and thermoluminescence characteristics of α-Al₂O₃:Mg and alumina-magnesium (Al-Mg) spinel crystal samples were tested. The thermoluminescence peak of the Al-Mg spinel was significantly stronger than that of the α-Al₂O₃:Mg crystal. The consistency between the model-calculated absorption spectra and the experimental results confirmed the theoretical predictions. Based on the experimental and computational results, the influence of Mg²⁺ substitutional doping in α-Al₂O₃ and the impact of the locally Mg-rich spinel on the optical and radiation performance of α-Al₂O₃:Mg crystals are elucidated.

X-ray imaging has garnered widespread interest in biomedical diagnosis and nondestructive detection. The exploration of radio-photoluminescence has hastened the advancement of X-ray information storage. However, significant challenges persist in achieving the prolonged imaging of curved objects without attenuation. Here, europium-doped strontium fluoride (SrF₂:Eu) is meticulously created to exhibit a linear response to an extensive range of X-ray doses (maximum dose > 5000 Gy), showcasing excellent X-ray information reading/erasing reusability properties (10 cycles). This is accompanied by a red-to-blue emission transition under UV excitation, sustaining for 150 days without attenuation. To elucidate the phenomena of irradiated photoluminescent discoloration and the reversible X-ray storage of SrF₂:Eu, we propose an electron-vacancy trap (valence conversion) mechanism, information stably retained by the SrF₂:Eu-based device under ambient conditions due to high energy barriers. The time-lapse readout capability is further demonstrated for three-dimensional imaging of curved objects (10 lp mm^-1) based on SrF₂:Eu embedded within a polydimethylsiloxane (SrF₂:Eu@PDMS). The SrF₂:Eu demonstrates time-lapse imaging, reversible radio-photoluminescence, and recoverable X-ray storage, offering a promising avenue for optical information encryption and anticounterfeiting applications.

A series of lead-free Rb₂ZrCl₆:xTe⁴⁺ (x = 0%, 0.1%, 0.5%, 1.0%, 2.0%, 3.0%, 5.0%, 10.0%) perovskite materials were synthesized through a hydrothermal method in this work. The substitution of Te⁴⁺ for Zr in Rb₂ZrCl₆ was investigated to examine the effect of Te⁴⁺ doping on the spectral properties of Rb₂ZrCl₆ and its potential applications. The incorporation of Te⁴⁺ induced yellow emission of triplet self-trapped emission (STE). Different luminescence wavelengths were regulated by Te⁴⁺ concentration and excitation wavelength, and under a low concentration of Te⁴⁺ doping (x ≤ 0.1%), different types of host STE emission and Te⁴⁺ triplet state emission could be achieved through various excitation energies. These luminescent properties made it suitable for applications in information encryption. When Te⁴⁺ was doped at high concentrations (x ≥ 1%), yellow triplet state emission of Te⁴⁺ predominated, resulting in intense yellow emission, which stemmed from strong exciton binding energy and intense electron-phonon coupling. In addition, a Rb₂ZrCl₆:2%Te⁴⁺@RTV scintillating film was fabricated and a spatial resolution of 3.7 lp/mm was achieved, demonstrating the potential applications of Rb₂ZrCl₆:xTe⁴⁺ in nondestructive detection and bioimaging.

Lu₂O₃:1%Eu and Lu₂O₃:8%Eu series single crystals were grown by optical floating zone method under air, N₂, and H₂-Ar mixed atmosphere (5 vol%H₂ and 95 vol%Ar). The effects of preparation atmosphere and doping concentration on the scintillation and photoluminescence properties have been investigated and discussed. Correlated measurements of afterglow curves, X-ray excited luminescence spectra, photoluminescence excitation and photoluminescence, photoluminescence decay, and thermal stimulated luminescence curves were performed. Although Eu(S₆) luminescence can be significantly depressed under oxidizing atmosphere, Lu₂O₃:8%Eu grown under weak reducing atmosphere presents the lowest afterglow intensity. This phenomenon was explained by different interstitial oxygen atom concentrations in the samples.