Photoluminescence properties of near ultraviolet excited Ca8La2(PO4)6O2:Sm3+ red orange phosphor
- 6 Downloads
Novel Ca8La2(PO4)6O2:Sm3+ phosphors are successfully synthesized in air by the high temperature solid state reaction method. The X-ray diffraction patterns, morphology, energy spectrum diagram, elemental mapping, luminescence properties, concentration-dependent emission spectra, thermal stability, and decay curves are investigated. The excitation spectrum of Ca8La2(PO4)6O2:8%Sm3+ phosphor monitored at 604 nm extends the region from 220 nm to 520 nm with many excitation spectral bands because of the O2−–Sm3+ charge transfer band and the f–f transitions of Sm3+ ion. Ca8La2(PO4)6O2:Sm3+ phosphor with excitation at 402 nm emits red orange light in the range of 550–770 nm with many emission spectral bands derived from the 4G5/2 → 6H5/2 (550–570 nm), 4G5/2 → 6H7/2 (570–630 nm), 4G5/2 → 6H9/2 (630–690 nm), and 4G5/2 → 6H11/2 (690–760 nm) transitions of Sm3+ ion, and the optimal Sm3+ concentration is ~ 8 mol%. The lifetime of Ca8La2(PO4)6O2:Sm3+ phosphor decreases from 1.39 to 1.11 ms with increasing Sm3+ concentration from 2 to 12 mol%. Ca8La2(PO4)6O2:Sm3+ phosphor has the good thermal stability and emission color stability. The luminous mechanism, concentration quenching, and thermal quenching are explained, respectively. The experimental results indicate that Ca8La2(PO4)6O2:Sm3+ phosphor as red orange component has a potential application in white LED based on near ultraviolet LED chip.
This work is financially supported by the National Natural Science Foundation of China (Nos. 51862015 and 51702051), Foundation of Jiang’xi Educational Committee (No. GJJ180564), Natural Science Foundation of Guangdong province (No. 2017A030313307), and National Undergraduate Training Program for Innovation and Entrepreneurship of China (No. 201910419014).
- 15.G. Zhu, Y. Shi, M. Mikami,Y. Shimomura, and Y. Wang, MRS Online Proceedings Library Archive, vol. 1592 (2014)Google Scholar
- 29.G. Liu, B. Jacquier, Spectroscopic Properties of Rare Earths in Optical Materials (Springer, Berlin, 2005)Google Scholar