Ultraviolet to near-infrared down-conversion in Bi3+–Yb3+ co-doped YAM phosphor. Issue 13 (September 2017)

• Record Type: Journal Article
• Authors: Zhydachevskyy, Ya.; Tsiumra, V.; Baran, M.; Lipińska, L.; Barzowska, J.; Suchocki, A.
• Is Part Of: Ceramics international. Volume 43:Issue 13(2017)
• Page Start: 10130
• Page End: 10136
• Publication Date: 2017-09
• Subjects: Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.05.034
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Direct measurements of external quantum yield (QY) were applied to down-converting phosphors of Y4 Al2 O9 (YAM) co-doped with Bi 3+ and Yb 3+ . The QY measurements were combined with studies of photoluminescence (PL), photoluminescence excitation (PLE) and photoluminescence decay kinetics. It was found that the energy transfer occurs mainly from one of the four possible types of Bi 3+ centers in YAM, namely Bi 3+ (I), with excitation and emission maxima at 278 nm and 360 nm, respectively. The absolute QY measurements show large discrepancy between the measured quantum efficiencies of the UV to near-IR down-conversion process and the efficiencies estimated from the shortening of the Bi 3+ luminescence decay time. Results presented in the paper testify the conversion ratio (which should be 2.0 for an ideal quantum cutting mechanism) to be no more than 1.0 in the studied material.