Dobroslawa Kasprowicz

Luminescence of Bi3TeBO9 micro-crystals doped with Nd3+ ions D. Kasprowicz,1 T. Zhezhera,1 P. Głuchowski,2 M. Chrunik,3 A. Majchrowski,3 1Faculty of Materials Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznań, Poland, 2Institute of Low Temperature and Structure Research of Polish Academy of Sciences, Okólna 2, 50-422 Wrocław, Poland 3Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland, е-mail: dobroslawa.kasprowicz@put.poznan.pl Bi3TeBO9 crystal is an excellent nonlinear optical material as well as an efficient host matrix for luminescent rare earth ions.1,2 Investigated Bi3TeBO9 crystalline powders were synthesized by means of the modified Pechini method. The vibrational properties of Bi3TeBO9 were studied using µ-Raman spectroscopy.3 Moreover, Bi3TeBO9 powders doped with Nd3+ ions show the efficient near-infrared quantum cutting process by cooperative down-conversion of active Bi3+ and Nd3+ ions. As a result, the investigated systems efficiently concentrate the ultraviolet/visible radiation in the near-infrared spectral range and can be potentially used as effective spectral converters in new multi-functional miniaturized optical devices. Acknowledgement This work was supported by the Research Project of the Polish Ministry of Sciences and Higher Education 0511/SBAD/2151. References [1] M. Xia, X. Jiang, Z. Lin, R. Li, J. Am. Chem. Soc. Journal, 2016, 138, 14190–14193. [2] M. Daub, M. Krummer, A. Hoffmann, L. Bayarjargal, H. Hillebrecht, Journal, Chem Eur J, 2016, 22, 1–8. [3] D. Kasprowicza, T. Zhezhera, A. Lapinski, M. Chrunik, A. Majchrowski, A.V. Kityk, Ya. Shchur, J. Alloys Comp., 2018, 782, 488–495.

An efficient near-infrared quantum cutting process by cooperative down-conversion of active Bi³⁺ and Nd³⁺ ions was demonstrated in Bi₃TeBO₉:Nd³⁺ phosphors. In particular, the near-infrared emission of Nd³⁺ ions enhanced by Bi³⁺ ions of a series of novel Bi₃TeBO₉:Nd³⁺ microcrystalline powders doped with Nd³⁺ ions in various concentrations was investigated. In order to investigate the luminescent properties of BTBO:Nd³⁺ powders, the excitation and emission spectra and the fluorescence decay time were measured and analyzed. In particular, the emission of Bi₃TeBO₉:Nd³⁺ at 890 and 1064 nm was excited at 327 nm (via energy transfer from Bi³⁺ ions) and at 586.4 nm (directly by Nd³⁺ ions). The highest intensity emission bands in near-infrared were detected in the spectra of Bi₃TeBO₉:Nd³⁺ doped with 5.0 and 0.5 at.% of Nd³⁺ ions upon excitation in ultraviolet and visible spectral range, respectively. The fluorescence decay lifetime monitored at 1064 nm for Bi₃TeBO₉:Nd³⁺ powders shows the single- or double-exponential character depending on the concentrations of Nd³⁺ ions. The possible mechanisms of energy relaxation after excitation Bi₃TeBO₉:Nd³⁺ powders in ultraviolet or visible spectral range were discussed. The investigated Bi₃TeBO₉:Nd³⁺ phosphors efficiently concentrate the ultraviolet/visible radiation in the near-infrared spectral range and can be potentially used as effective spectral converters. Graphical

The efficiency of the 1.5 μm emission associated with the ⁴I_13/2 → ⁴I_15/2 transition of Er³⁺ ions of a series of Er³⁺ and Yb³⁺/Er³⁺-doped Bi₂ZnOB₂O₆ microcrystalline powders was investigated.

A series of novel KGd(WO ₄ ) ₂ crystalline powders doped with Yb ³⁺ /Tm ³⁺ , Yb ³⁺ /Er ³⁺ and Yb ³⁺ /Ho ³⁺ were synthesized using a modified Pechini method.