Adjustable multicolor up-energy conversion in light-luminesce in Tb3+/Tm3+/Yb3+ co-doped oxyfluorifFde glass-ceramics containing Ba2LaF7 nanocrystals

Zhencai Li,Peng Ren,Jianbei Qiu,Yong Yang,Dacheng Zhou

doi:10.1038/s41598-017-05943-4

Zhencai Li, Peng Ren + Show 3 more

Open Access

https://doi.org/10.1038/s41598-017-05943-4

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Journal: Scientific Reports	Publication Date: Jul 26, 2017
Citations: 13	License type: open-access

Affiliation: Kunming University of Science and Technology

Abstract

Transparent oxyfluoride glasses with highly efficient up-energy conversion (UEC) luminescence were developed in the 45SiO2-15Al2O3-12Na2CO3-21BaF2-7LaF3-xTbF3-yTmF3-zYbF3 composition (in mol%), and structural investigation by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of face-centered cubic Ba2LaF7 nanocrystals. The colors of UEC luminescences could be tuned easily by adjusting the concentration of doped rare earth ions and the excitation power of laser simultaneously. The relationship between the emission intensity of Tb3+/Tm3+/Yb3+ co-doped oxyfluoride glass-ceramics and the excitation pump power revealed that three-photon and two-photon absorptions predominated in the conversion process from the infrared into blue and red luminescences, respectively. A novel UEC mechanism of red emission from Tm3+ was proposed, energy transfers from Yb3+ to Tm3+ and Tb3+ and from Tm3+ to Tb3+ were evidenced. The possible mechanism responsible for the color variation of UEC in Tb3+/Tm3+/Yb3+ co-doped was discussed.

Highlights

Confirmed the formation of face-centered cubic Ba2LaF7 nanocrystals
The high resolution transmission electron microscopy (HRTEM) image with the d-spacing structure is shown in Fig. 1(d), and the d-spacing value of (200) plane is determined as 0.301 nm
We have demonstrated the highly efficient red, green and blue up-energy conversion (UEC) luminescences in the Tb3+/ Tm3+/Yb3+ co-doped SAB glass-ceramics based on multiphoton excitation in this paper

Summary

Results and Discussion

Emission bands at 476 nm (Tm3+: 1G4 → 3H6) and 657 nm (Tm3+: 3F2,3 → 3H6) are enhanced dramatically with increasing concentration of Tm3+ ions in the SABTm glass-ceramics, and that at around 546 nm originated from Tb3+ ions increases These results imply that energy transfer from Tm3+ to Tb3+ ions may occur during the UEC process. The emission color of SABTm-1-640 glass-ceramics changes from yellow-green to white when the exaction power of laser increases from 0.26 to 1.65 W, which may be ascribed to the variation of the intensity ratio of RGB luminescences. The green emission is a two-photon absorption process

Conclusions

Author Contributions

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