Spectral-luminescent Properties of Glasses of the (Y1 – xYbx)2O3–Al2O3–B2O3–SiO2 + Cr2О3 + Na2O System

• Published in: Optics and spectroscopy Vol. 131; no. 7; pp. 564 - 572
• Main Authors: Malashkevich, G. E., Kouhar, V. V., Ramanenka, A. A., Azarko, I. I., Sigaev, V. N., Golubev, N. V, Ziyatdinova, M. Z., Ignatieva, E. S., Bahramov, S. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.07.2023; Springer Nature B.V
• Subjects: Aluminum oxide; Boron oxides; Charge transfer; Lasers; Luminescence; Optical Devices; Optical properties; Optics; Oxidation; Photonics; Physics; Physics and Astronomy; Silicon dioxide; Trivalent chromium; Ytterbium; Yttrium; Yttrium oxide; quantum yield of luminescence; sensitization and quenching of luminescence; EPR spectra; chromium and ytterbium ions
• ISSN: 0030-400X; 1562-6911
• DOI: 10.1134/S0030400X23050120

Fused yttrium-alumoborate glasses doped with ytterbium, silicon, chromium, and sodium were synthesized. The influence of the matrix on the “spectroscopic behavior” of chromium ions and the efficiency of their sensitization of Yb 3+ luminescence was established by spectral-luminescence and EPR studies. It was found that (1) chromium in alkali-free glasses is mainly in the oxidation degree Cr(III) with an appreciable admixture of Cr(IV) and Cr(V), (2) the partial replacement of Al 2 O 3 or B 2 O 3 by SiO 2 and Y 2 O 3 by Yb 2 O 3 affects to a different extent the relative concentration of optical centers of chromium ions, (3) the addition of alkali results in the formation of Cr(VI) centers as a result of oxidation of less charged chromium ions and predominantly tetracoordinated Cr 4+ and Cr 5+ , (4) Cr 3+ ions make the main contribution to the luminescence sensitization of Yb 3+ ions, while Cr 4+ ions and to a lesser extent Cr 5+ play the role of luminescence quencher and internal filter. Sensitization of Yb 3+ luminescence through the charge transfer band in Cr(VI) was found. An alkaline glass doped with Cr and Yb upon excitation through the sensitizer produced a luminescence quantum yield of 32% and the conditions for its enhancement were considered. It is shown that the temperature quenching of luminescence of Cr–Yb-containing glasses is significantly lower than that of Cr-containing glasses.