High Quantum Efficiency Rare-Earth-Doped Gd2O2S:Tb, F Scintillators for Cold Neutron Imaging

Abstract

High-resolution neutron radiography provides novel and stirring opportunities to investigate the structures of light elements encased by heavy elements. For this study, a series of Gd2O2S:Tb, F particles were prepared using a high-temperature solid phase method and then used as a scintillation screen. Upon reaching 293 nm excitation, a bright green emission originated from the Tb3+ luminescence center. The level of F doping affected the fluorescence intensity. When the F doping level was 8 mol%, the fluorescence intensity was at its highest. The absolute quantum yield of the synthesized particles reached as high as 77.21%. Gd2O2S:Tb, F particles were applied to the scintillation screen, showing a resolution on the neutron radiograph as high as 12 μm. These results suggest that the highly efficient Gd2O2S:Tb, F particles are promising scintillators for the purposes of cold neutron radiography.

High-Quality Ultrathin Gd2O2S Nanosheets with Oxygen Vacancy-Decorated rGO for Enhanced Electromagnetic Wave Absorption

“…The XPS survey spectrum of Gd 2 O 2 S/rGO composites, shown in Figure S4, reveals the presence of Gd, O, S, and C elements, which can be seen from their corresponding binding energy. In Figure 2d, the Gd 3+ 4d XPS spectrum shows two peaks centered at 147.4 and 142.2 eV, which could be ascribed to Gd 3+ 4d 3/2 and Gd 3+ 4d 5/2 , respectively, 38,39 confirming the presence of the Gd 3+ valence state in the Gd 2 O 2 S/rGO composites. The XPS spectrum for O 1s in Figure 2e reveals two peaks at 532.0 and 529.6 eV, which could be assigned to surface oxygen defects (or oxygen vacancy) and O 2− 1s (oxygen−metal bonds, Gd−O), 39 suggesting the appearance of oxygen defects.…”

“…In Figure 2d, the Gd 3+ 4d XPS spectrum shows two peaks centered at 147.4 and 142.2 eV, which could be ascribed to Gd 3+ 4d 3/2 and Gd 3+ 4d 5/2 , respectively, 38,39 confirming the presence of the Gd 3+ valence state in the Gd 2 O 2 S/rGO composites. The XPS spectrum for O 1s in Figure 2e reveals two peaks at 532.0 and 529.6 eV, which could be assigned to surface oxygen defects (or oxygen vacancy) and O 2− 1s (oxygen−metal bonds, Gd−O), 39 suggesting the appearance of oxygen defects. As detailed in Figure 2f, there were three apparent peaks in S 2p, with binding energy peaks positioned at 170.7, 162.4, and 161.2 eV attributed to S 2− 2p 3/2 , S 2− 2p 1/2 , and S 2− 2p 3/2 , respectively.…”

Systematic synthesis of (Gd1−xLax)2O2SO4:Tb3+ and (Gd1−xLax)2O2S:Tb3+ nanophosphors for remarkably enhanced luminescence

“…8 The Gd 2 O 2 S:Tb 3+ bulk ceramic fabricated via sintering, on the other hand, finds important application in scintillation bio-probing, high-resolution neutron radiography and X-ray computed tomography for its excellent attenuation property, scintillation efficiency, and imaging quality. [9][10][11] Gd 2 O 2 S-based phosphors are conventionally synthesized via flux reaction at 1200-1300 • C, which uses oxide and/or carbonate as the rare-earth (RE) source, elemental sulfur, and/or sodium thiosulfate as the sulfur source and alkali carbonate and/or halide as a reflux. 12,13 Though the resulted powder has a high crystallinity because of its micron-sized large particles, contamination by alien cations and anions is hardly evitable.…”

“…Besides, Gd 2 O 2 S:Tb 3+ nano‐colloid was reported to be a useful fluorescent probe in biomarkers 8 . The Gd 2 O 2 S:Tb 3+ bulk ceramic fabricated via sintering, on the other hand, finds important application in scintillation bio‐probing, high‐resolution neutron radiography and X‐ray computed tomography for its excellent attenuation property, scintillation efficiency, and imaging quality 9–11 . Gd 2 O 2 S‐based phosphors are conventionally synthesized via flux reaction at 1200–1300°C, which uses oxide and/or carbonate as the rare‐earth (RE) source, elemental sulfur, and/or sodium thiosulfate as the sulfur source and alkali carbonate and/or halide as a reflux 12,13 .…”