Eu2+ Doping Concentration-Induced Site-Selective Occupation and Photoluminescence Tuning in KSrScSi2O7:Eu2+ Phosphor

Shunqi Lai; Ming Zhao; Yifei Zhao; Maxim S Molokeev; Zhiguo Xia

doi:10.1021/acsmaterialsau.1c00081

Eu²⁺ Doping Concentration-Induced Site-Selective Occupation and Photoluminescence Tuning in KSrScSi₂O₇:Eu²⁺ Phosphor

ACS Mater Au. 2022 Feb 24;2(3):374-380. doi: 10.1021/acsmaterialsau.1c00081. eCollection 2022 May 11.

Authors

Shunqi Lai¹, Ming Zhao², Yifei Zhao^{1

3}, Maxim S Molokeev^{4

5

6

7}, Zhiguo Xia¹

Affiliations

¹ State Key Laboratory of Luminescent Materials and Devices and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China.
² Institute of Information Photonics Technology, Faculty of Science, Beijing University of Technology, Beijing 100124, China.
³ Department of Chemistry, City University of Hong Kong, Kowloon 999077, Hong Kong, China.
⁴ Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk 660036, Russia.
⁵ Research and Development Department, Kemerovo State University, Kemerovo 650000, Russia.
⁶ Department of Physics, Far Eastern State Transport University, Khabarovsk 680021, Russia.
⁷ Siberian Federal University, Krasnoyarsk 660041, Russia.

Abstract

Regulation of Eu²⁺ dopants in different cation sites of solid-state materials is of great significance for designing multicolor phosphors for light-emitting diodes (LEDs). Herein, we report the selective occupation of Eu²⁺ for multiple cationic sites in KSrScSi₂O₇, and the tunable photoluminescence from blue to cyan is realized through Eu²⁺ doping concentration-dependent crystal-site engineering. Eu²⁺ preferably occupies the K and Sr sites in KSrScSi₂O₇ at a low doping concentration, resulting in a 440 nm blue emission. As the Eu²⁺ concentration increases, a new Eu²⁺ substitution pathway is triggered, that is, Eu²⁺ enters the Sc site, leading to the red-shifted emission spectra from 440 to 485 nm. The doping mechanism and photoluminescence properties are corroborated by structural analysis, optical spectroscopy study, and density functional theory calculations. The optical properties of the as-fabricated white LEDs are studied, which demonstrates that these phosphors can be applied to full-spectrum phosphor-converted LEDs. This study provides a new design strategy to guide the development of multicolor Eu²⁺-doped oxide phosphors for lighting applications.