Ca(Mg0.8Al0.2)(Si1.8Al0.2)O6:Ce3+,Tb3+ Phosphors: Structure Control, Density-Functional Theory Calculation, and Luminescence Property for pc-wLED Application

Zhengce An; Songtian Che; Yanhua Song; Xiangting Zhang; Rujia Dong; Dan Zhang; Xiuqing Zhou; Zhan Shi; Haifeng Zou

doi:10.1021/acs.inorgchem.0c00061

Ca(Mg_0.8Al_0.2)(Si_1.8Al_0.2)O₆:Ce³⁺,Tb³⁺ Phosphors: Structure Control, Density-Functional Theory Calculation, and Luminescence Property for pc-wLED Application

Inorg Chem. 2020 Apr 6;59(7):4790-4799. doi: 10.1021/acs.inorgchem.0c00061. Epub 2020 Mar 9.

Authors

Zhengce An¹, Songtian Che², Yanhua Song¹, Xiangting Zhang¹, Rujia Dong¹, Dan Zhang¹, Xiuqing Zhou¹, Zhan Shi³, Haifeng Zou¹

Affiliations

¹ College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
² Department of Ocular Fundus Disease, The Second Hospital of Jilin University, Changchun 130022, People's Republic of China.
³ State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.

PMID: 32149513
DOI: 10.1021/acs.inorgchem.0c00061

Abstract

A modified structure Ca(Mg_0.8Al_0.2)(Si_1.8Al_0.2)O₆ (denoted as CMASO) from the evolution of CaMgSi₂O₆ (denoted as CMSO) codoped with Ce³⁺ and Tb³⁺ ions was designed successfully by solid reaction method for application in phosphor-converted white-light-emitting diode (pc-wLED). The Rietveld refinement of these two structures verified the changes derived from the replacement of some of the Mg²⁺ and Si⁴⁺ ions by Al³⁺ ions. The band gaps were calculated by density-functional theory (DFT) calculation method to verify the change of Al³⁺ ions replacing further, and the diffuse reflectance spectra (DRS) proved the veracity of the calculation result. The phosphors CMASO:Ce³⁺ showed blue emission excited by a wider excitation wavelength from 280 nm to 370 nm. The change of structure lead to the absorbable range broaden and the emission peak shifted to longer wavelength, compared with CMSO:Ce³⁺, although the amount of emitting center was the same. The reason for these phenomena was discussed in detail. The codoped phosphors CMASO:Ce³⁺,Tb³⁺ exhibited different emission colors from blue to green as the concentration of Tb³⁺ ions increased. Combined with commercial red phosphor CaAlSiN₃:Eu²⁺ and ultraviolet LED (UV-LED) chips, the selected appropriate samples achieved white emission. The correlated color temperature (CCT) was 6137 K and the color rendering index (Ra) was 80.5, indicating that they could act as potential phosphors for possible applications in pc-wLED.