Seeking the optimal LaTaO4:Eu phosphor

被引：12

作者：

Bleier, Grant C. ^{[1
]}

Nyman, May ^{[1
]}

Rohwer, Lauren E. S. ^{[1
]}

Rodriguez, Mark A. ^{[1
]}

机构：

[1] Sandia Natl Labs, Albuquerque, NM 87185 USA

来源：

JOURNAL OF SOLID STATE CHEMISTRY | 2011年 / 184卷 / 12期

关键词：

Orthotantalate; Rare-earth; Europium; Phosphor; Solid-state lighting; LED CONVERSION PHOSPHORS; LUMINESCENCE PROPERTIES; CRYSTAL-GROWTH; PHOTOLUMINESCENCE PROPERTIES; STRUCTURAL-PROPERTIES; SM; GD; ND; LA; LN;

D O I：

10.1016/j.jssc.2011.10.008

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Lanthanum orthotantalate, LaTaO4, is an excellent host lattice for rare-earth luminescent ions such as Eu3+ for red emission. However, there are multiple RETaO4 (RE=rare earth) polymorphs, and the stability of these is controlled predominantly by the RE-radius. Thus it is difficult to obtain a pure phase of LaTaO4:Eu as Eu concentration and consequently the RE radius is varied. We recently reported a 'soft-chemical' route that allows crystallization of pure-phase LaTaO4:Eu at temperatures as low as 800 degrees C. in the current report, we investigate polymorph evolution and Eu emission as a function of Eu concentration and annealing temperature. We obtain a maximum quantum yield (QY) of 83% at the highest Eu substitution (25%) for which the low temperature orthorhombic (Pbca) polymorph is stable. Therefore, QY is not limited necessarily by concentration quenching; rather it is limited by polymorph stability as the RE-radius decreases with increasing Eu substitution. (C) 2011 Elsevier Inc. All rights reserved.

引用

页码：3221 / 3227

页数：7

共 29 条

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