Self‐Activated Vanadate Compounds Toward Realization of Rare‐Earth‐Free Full‐Color Phosphors. Issue 4 (22nd January 2015)

• Record Type: Journal Article
• Authors: Matsushima, Yuta; Koide, Takuhiro; Hiro‐Oka, Masahiro; Shida, Minori; Sato, Akane; Sugiyama, Sho; Ito, Michimasa; McKittrick, J.
• Is Part Of: Journal of the American Ceramic Society. Volume 98:Issue 4(2015)
• Page Start: 1236
• Page End: 1244
• Publication Date: 2015-01-22
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.13463
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace13463-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Rare‐earth‐free phosphors based on vanadate compounds were investigated, where the vanadates included chloride vanadates (M<sup>II</sup><sub>2</sub>VO<sub>4</sub>Cl), pyrovanadates (M<sup>II</sup><sub>2</sub>V<sub>2</sub>O<sub>7</sub>), orthovanadates (M<sup>II</sup><sub>3</sub>(VO<sub>4</sub>)<sub>2</sub>) with divalent cations M<sup>II</sup> of Mg, Sr, Ba, and Zn, and oxofluorovanadates (A<sup>I</sup>VOF<sub>4</sub>) with an alkali metal A<sup>I</sup>. A chloride pyrolysis method and a liquid phase precipitation method were proposed for preparing the chloride vanadates and pyro‐ and orthovanadates, respectively. These vanadate compounds showed self‐activated photoluminescence (PL) based on the VO<sub>4</sub> clusters against the ultraviolet (UV) light irradiation. The colors of PL covered almost the whole visible‐light region from blue to yellow as Sr<sub>2</sub>VO<sub>4</sub>Cl (deep blue), Ca<sub>2</sub>VO<sub>4</sub>Cl (sky blue), Ba<sub>2</sub>V<sub>2</sub>O<sub>7</sub> (green), Sr<sub>2</sub>V<sub>2</sub>O<sub>7</sub> (yellowish green), Zn<sub>3</sub>(VO<sub>4</sub>)<sub>2</sub> (yellow), and Mg<sub>3</sub>(VO<sub>4</sub>)<sub>2</sub> (yellow). A correlation was suggested from these compounds between the luminescent colors and the structural feature as the longer V–O distances in the VO<sub>4</sub> tetrahedra in the crystal structures led to the longer wavelength in PL. This seemed to be also applicable for the oxofluorovanadates A<sup>I</sup>VOF<sub>4</sub> (A<sup>I</sup> = K and Cs) which contain the VOF<sub>4</sub> polyhedra with one O<sup>2−</sup> ion and four F<sup>‐</sup> ions as the ligands, as they exhibited the reddish PL.</p> </abstract>