标题：Luminescence, energy transfer, and up-conversion mechanisms of Yb3+and Tb3+co-doped LaNbO4
作者：Huang, Huining ;Wang, Tao ;Zhou, Haifeng ;Huang, Dapeng ;Wu, Yaqiang ;Zhou, Guangjun ;Hu, Jifan ;Zhan, Jie
作者机构：[Huang, Huining ;Wang, Tao ;Huang, Dapeng ;Wu, Yaqiang ;Zhou, Guangjun ;Hu, Jifan ;Zhan, Jie ] State Key Laboratory of Crystal Materials, Shandong Uni 更多
来源：Journal of Alloys and Compounds
摘要：Novel green-emitting Yb3+and Tb3+co-doped LaNbO4particles were prepared through a facile sol-gel and combustion method. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric and differential thermal analysis (TG-DTA), up-conversion luminescence (UCL) with different powers and varied concentrations, and luminescent lifetimes were employed to test the prepared samples. The XRD data exhibit that a sample with high crystallinity can be acquired at 1000 °C. FE-SEM images show homogeneous and spherical grains after Yb3+and Tb3+are co-doped in the LaNbO4samples. TG-DTA reveals that the LaNbO4synthetic process is accompanied by a temperature increase. In our work, we utilize a 980 nm laser to excite Yb3+ions to achieve the2F7/2 → 2F5/2transition, and the LaNbO4:Yb3+, Tb3+sample exhibits intense green emission. Luminescent spectra at different powers demonstrated the two-photon absorption process; meanwhile, the corresponding energy transfer mechanism from Yb3+to Tb3+and the emission of Tb3+under 980 nm laser excitation was described via an energy level diagram. Moreover, concentration-dependent up-conversion luminescent properties were systematically explored, and it was confirmed that LaNbO4:0.15Yb3+,0.02Tb3+exhibits the strongest luminescent properties. In particular, as the content of Yb3+ions increases, the5D4→7F6transition quickly becomes stronger, resulting in the emitted color shifting from green to blue. Therefore, the emitted color can be tuned by adjusting the content of Yb3+ions. The excellent up-conversion emission properties of the obtained samples allow for their potential application in the fields of 3D display technologies and solid-state lasers.
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