Large Redshifts in Emission and Excitation from Eu²⁺-Activated Sr₂SiO₄ and Ba₂SiO₄ Phosphors Induced by Controlling Eu²⁺ Occupancy on the Basis on Crystal-Site Engineering

Yasushi Sato^1*, Hiroki Kuwahara², Hideki Kato², Makoto Kobayashi², Takaki Masaki³, Masato Kakihana^2*

¹Department of Chemistry, Faculty of Science, Okayama University of Science, Okayama, Japan.
²Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan.
³School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Republic of Korea.

DOI: 10.4236/opj.2015.511031                

Abstract

The photoluminescence properties of Eu²⁺-activated α’-Sr₂SiO₄ and α’-Ba₂SiO₄ with a high Eu²⁺ concentration were investigated. In the case of Sr_2-xEu_xSiO₄, emission was shifted from 585 to 611 nm with increasing the total Eu2+ concentration (x) from 0.1 to 0.8. This trend was similar to that in Ba_2-xEu_xSiO₄, where the emission was shifted from 513 to 545 nm. The large redshifts in both the excitation and emission spectra were discussed in terms of the Eu²⁺ occupancies on two kinds of M sites and their local structural changes (M: Sr and Ba).

Keywords

Photoluminescence, Red-Emitting Phosphors, Green-Emitting Phosphors, Orthosilicates, Crystal-Site Engineering

Conflicts of Interest

The authors declare no conflicts of interest.

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