Improved scintillation performance of neodymium ions through blocking energy migration from activators to surface defects

Scintillators that convert ionizing radiation into visible photons have been broadly studied owing to their potential applications in security inspection and medical imaging fields. Compared with visible emission wavelengths, the near-infrared light usually possesses deeper penetration depth in serveral cases. Herein, BaGdF5: Ce@BaGdF5: Nd@BaYF5 core/dual-shell nanocrystals are employed to achieve efficient NIR fluorescence emission under X-ray excitation. Our results reveal that the Nd3+ emission in BaGdF5: Ce@BaGdF5: Nd@BaYF(5 )is stronger than that of BaGdF5: Ce@BaGdF5: Nd@BaGdF5, which is owing to the significantly blocked energy migration from Gd3+ ions to surface defects. With the growth of a thicker BaYF5 shell, the Nd3+ emisison intensity is further improved. Moreover, the radioluminescence intensity of the present studied BaGdF5: Ce@BaGdF5: Nd@BaYF5 is better than that of NaGdF4: Ce@NaGdF4: Nd@NaYF4 nanocrystals with similar doping content and mean particle size.

Automated summary

The study shows that BaGdF5: Ce@BaGdF5: Nd@BaYF5 exhibits stronger Nd3+ emission compared to BaGdF5: Ce@BaGdF5: Nd@BaGdF5, due to blocked energy transfer. Increasing the thickness of BaYF5 shell further enhances Nd3+ emission intensity. The radioluminescence intensity of BaGdF5: Ce@BaGdF5: Nd@BaYF5 outperforms that of NaGdF4: Ce@NaGdF4: Nd@NaYF4 nanocrystals with similar doping content and particle size.