Enhanced multimodal luminescence and ultrahigh stability Eu³⁺-doped CsPbBr₃ glasses for X-ray detection and imaging

Abstract

As an emerging scintillation material, metal halide perovskite ( CsPbX 3 ) has been deemed the most potentially valuable candidate in X-ray detection and medical imaging. Nevertheless, it is a continuing challenge to implement efficient radioluminescence (RL) with high radiation stability and moisture resistance. Moreover, the optimized luminescence properties and excellent uniformity of CsPbX 3 glass are also key points for obtaining perfect X-ray images. Herein, we have successfully precipitated Eu 3 + -doped CsPbBr 3 nanocrystals (NCs) with improved photoluminescence quantum yield ( ≈ 58.6 % ) because partial Eu 3 + entered the perovskite lattice in a robust borosilicate glass matrix by in situ crystallization. The small amount of Eu addition made the lattice of NCs shrink and promoted uniform distribution of CsPbBr 3 NCs in the glass, which effectively reduced the light scattering of the sample. Subsequently, multimodal RL intensity of the CsPbBr 3 / CsPbBr 3 :xEu NCs glasses (CPB-0Eu/CPB-xEu) as a function of X-ray dose rate showed a superlinear relationship to the benefit of obtaining satisfactory X-ray images. Also, the outstanding radiation stability and water resistance of CPB-xEu were confirmed due to the protection of the robust glass matrix. Finally, an X-ray imaging system using a CPB-xEu scintillator was constructed, and the spring in the opaque sample was legibly detected under the motivation of X-rays, indicating that CsPbX 3 glasses possess extensive application prospects in terms of X-ray detection and medical imaging.

Advanced Halide Scintillators: From the Bulk to Nano

“…RE ions in precursor glass probably serve as nucleating agents that promote rapid growth and precipitation of CsPbX 3 , thus preparing more uniformly distributed, smaller crystals. [ 342,344 ] A similar effect was achieved by introducing AgCl into the precursor glass. [ 343 ]…”

“…Incorporation of CsPbX 3 NCs into a glass matrix has attracted considerable attention recently, because it promises superior stability compared with the plastic matrices. [ 341–346 ] The fabrication technique is a conventional melt‐quenching process. To crystallize CsPbX 3 NCs in the precursor glass, several hours of heat treatment are required, ranging from 340 °C for 15 h [ 343 ] to 550 °C for 4–18 h. [ 346 ]…”

“…Not only the emission from CsPbX 3 was enhanced, [ 346 ] but in case of Eu 3+ doping, strong emission from dopant emerged to accompany the enhanced CsPbX 3 emission, that caused larger Stokes shift in such a material, effectively suppressing self‐absorption. [ 342,344 ]…”

“…Improved stability against various conditions was successfully tested, for example, against humidity, [ 342,344,346 ] heat–cooling cycles, [ 343 ] and X‐ray exposure. [ 344 ] Exposing the material to high radiation doses (for 120 h by dose rate of 8 mGy air s −1 ) caused the radiation damage, but it was reversible by thermal annealing at 300 °C for 3 h. [ 345 ] Overall, this glass ceramics based on CsPbX 3 NCs was proven very promising for scintillation application. High‐quality X‐ray images were achieved [ 342,344,345 ] with spatial resolution as high as ≈15–17 lp mm −1 .…”

“…Incorporation of CsPbX 3 NCs into a glass matrix has attracted considerable attention recently, because it promises superior stability compared with the plastic matrices. [341][342][343][344][345][346] The fabrication technique is a conventional melt-quenching process. To crystallize CsPbX 3 NCs in the precursor glass, several hours of heat treatment are required, ranging from 340 C for 15 h [343] to 550 C for 4-18 h. [346] A basic example of such nanocomposites was studied in the work by Wang et al [341] The authors annealed borate precursor glass at 470 and 520 C for just 1 h. They demonstrated that higher temperature led to an opaque sample due to too large NCs causing significant light scattering.…”