Structural and Optical Properties of Tunable Warm‐White Light‐Emitting ZrO2:Dy3+–Eu3+ Nanocrystals. Issue 5 (28th February 2013)

• Record Type: Journal Article
• Authors: Das, Subrata; Yang, Che‐Yuan; Lu, Chung‐Hsin; Dunn, B.
• Is Part Of: Journal of the American Ceramic Society. Volume 96:Issue 5(2013)
• Page Start: 1602
• Page End: 1609
• Publication Date: 2013-02-28
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12149
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" xml:lang="en" id="jace12149-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A series of Dy<sup>3+</sup>–Eu<sup>3+</sup>‐codoped ZrO<sub>2</sub> nanocrystals with tetragonal and cubic symmetry was synthesized via a wet chemical reaction. When the Eu<sup>3+</sup>‐doping content was fixed, the crystal structure could be stabilized from the mixed phase to single cubic phase by simply adjusting the content of Dy<sup>3+</sup>. The cubic ZrO<sub>2</sub>:Dy<sup>3+</sup>–Eu<sup>3+</sup> nanoparticles exhibited spherical and nonagglomerated morphology. The effective phonon energy of cubic ZrO<sub>2</sub>:5%Dy<sup>3+</sup>–5%Eu<sup>3+</sup> was calculated to be 445 cm<sup>−1</sup>, which is lower than the previously reported results. Extensive luminescence studies of ZrO<sub>2</sub>:Dy<sup>3+</sup>–Eu<sup>3+</sup> as a function of Dy<sup>3+</sup> content demonstrated that the dopant concentration and its site symmetry play an important role in the emissive properties. Under 352 nm excitation, the increment of Dy<sup>3+</sup> concentration in ZrO<sub>2</sub>:Dy<sup>3+</sup>–Eu<sup>3+</sup> led to an increase in orange (590 nm) and red (610 nm) emissions of Eu<sup>3+</sup> ions, which are attributed to the <sup>5</sup>D<sub>0</sub>→<sup>7</sup>F<sub><italic>J</italic></sub>(<italic>J</italic> = 1, 2) transitions of Eu<sup>3+</sup> ions. This increment is possibly due to the efficient energy transfer (ET) <sup>4</sup>F<sub>9/2</sub>:Dy<sup>3+</sup>→<sup>5</sup>D<sub>0</sub>:Eu<sup>3+</sup>. The phosphors can generates light from yellow through near white and eventually to warm white by properly tuning the concentration of Dy<sup>3+</sup> ions through the ET and change in site symmetry. These phosphors may be promising as warm‐white‐/yellow‐emitting phosphors.</p> </abstract>