Tunable luminescence of (Sr1-XCaX)(1.97)MgSi2O7:0.03Eu(2+) solid solution phosphors for cirtopic LEDs
Authors: Wang, W; Jiang, ZQ; Wu, RX; Li, CJ; Yao, R; Wei, X; Guo, TT; Fan, JB; Ni, L; Duan, L
MATERIALS RESEARCH EXPRESS
Volume: 6 Issue: 10 Published: OCT 2019 Language: English Document type: Article
In order to realize the 490 nmsingle-peak emission for cirtopic light-emitting diodes (LEDs), a series of iso-structural (Sr1-xCax)(1.97)MgSi2O7:0.03Eu(2+) (x = 0, 0.2, 0.3, 0.4, 0.8, 1) phosphors with melilite structure have been prepared by traditional solid-state reaction. The x-ray Diffraction (XRD) patterns and regular lattice parameters confirm the formation of (Sr1-xCax)(2)MgSi2O7 solid solution. Broad band excitation spectra were observed in the ultraviolet region of these phosphors. The photoluminescence spectra of (Sr1-xCax)(1.97)MgSi2O7:0.03Eu(2+) solid solution phosphors give continuously tunable emission from 466 [Sr2MgSi2O7: Eu2+, (x = 0)] to 527 nm [Ca2MgSi2O7:Eu2+, (x = 1)]. Phosphors with an illuminating centre at 486 and 490 nm were obtained when adjusting the x value to 0.3 and 0.4 respectively. By measuring the quantum efficiency (QE) and contrasting with the spectral sensitivity function of cirtopic, (Sr1-xCax)(1.97)MgSi2O7:0.03Eu(2+) (x = 0.3, 0.4) phosphors have potential value in cirtopic vision.