Synthesis And Upconversion Properties Of LiTaO₃ Doped With Rare Earth

Stoichiometric Lithium tantalate (SLT) polycrystalline powders and LiTaO₃ polycrystalline powder of the solid-liquid congruent point composition(CLT) and Mg2+ doped CLT were synthesized by solid-state reaction method. We determined the stoichiometric LiTaO₃ for the optimal matrix luminous by comparison the intensity of the up-conversion luminescence in different experimental matrix. it was found that the best conditions was 22 hours at 1200℃by testing different sintering time on the luminescence properties optimum process conditions.The results of X-ray diffraction showed that there was no new phase appeared in LiTaO₃ polycrystalline powder. The combination of the results of X-ray diffraction and Ultraviolet-visible absorption spectrum were used to analysis the location of the rare-earth ions.Bright green and weak red color was obtained in Er³⁺ doped LiTaO₃ polycrystalline powder under diode laser excitation of 980 nm, and the up-conversion emission intensity of green and red color were all enhanced through increasing the doped Er³⁺ ion concentration. Bright green and red light were obtained in Er³⁺/Yb³⁺-doped LiTaO₃ polycrystalline powder under diode laser excitation of 980 nm, and the up-conversion emission intensity of green and red light were all enhanced through increasing the the doped Yb³⁺ ion concentration. Obviously, the red up-conversion emission intensity enhanced more than the green up-conversion emission intensity. The green emission peaks centered at 530nm and 550nm are attributed to the 2H11/2/4S3/2â†'4I15/2 transitions of the Er³⁺ ions, and the observed red emission peaks centered at 670 nm are attributed to the Er³⁺ ion 4F9/2â†'4I15/2 transition.White upconversion emission were obtained in Er³⁺/Tm³⁺/Yb³⁺-doped LiTaO₃ polycrystalline powder under diode laser excitation of 980 nm through adjusting the doped Er³⁺/Tm³⁺/Yb³⁺ ions concentrations in the room temperature.