New Yellow-Emitting Whitlockite-type Structure Sr_1.75Ca_1.25(PO₄)₂:Eu²⁺ Phosphor for Near-UV Pumped White Light-Emitting Devices

Abstract

New compound discovery is of interest in the field of inorganic solid-state chemistry. In this work, a whitlockite-type structure Sr1.75Ca1.25(PO4)2 newly found by composition design in the Sr3(PO4)2-Ca3(PO4)2 join was reported. Crystal structure and luminescence properties of Sr1.75Ca1.25(PO4)2:Eu(2+) were investigated, and the yellow-emitting phosphor was further employed in fabricating near-ultraviolet-pumped white light-emitting diodes (w-LEDs). The structure and crystallographic site occupancy of Eu(2+) in the host were identified via X-ray powder diffraction refinement using Rietveld method. The Sr1.75Ca1.25(PO4)2:Eu(2+) phosphors absorb in the UV-vis spectral region of 250-430 nm and exhibit an intense asymmetric broadband emission peaking at 518 nm under λex = 365 nm which is ascribed to the 5d-4f allowed transition of Eu(2+). The luminescence properties and mechanism are also investigated as a function of Eu(2+) concentration. A white LED device which is obtained by combining a 370 nm UV chip with commercial blue phosphor and the present yellow phosphor has been fabricated and exhibit good application properties.

Microwave sol–gel synthesis and upconversion photoluminescence properties of CaGd2(WO4)4:Er3+/Yb3+ phosphors with incommensurately modulated structure

“…One such class of materials is complex oxide photoluminescence crystals which exhibit different compositions and spectroscopic properties, high operation durability and emission efficiency, and a pronounced chemical stability in the air [1][2][3][4][5][6][7][8][9][10][11]. Recently, rare-earth-doped upconversion (UC) photoluminescence crystals have attracted great attention as functional materials for the frequency conversion from near infrared to visible spectral range [4,[12][13][14][15][16][17][18][19][20].…”

Synchronous red and blue emitting Ca 3 (PO 4 ) 2 :Eu 2+ , Mn 2+ phosphors applicable for plant-lighting

“…For the Eu 2+ -Mn 2+ co-doped TCP sample, broad red emission band positioned at 660 nm accompanied with the just mentioned blue emission band are detected. Apparently, the new emerging red emission results from the 4 T 1 ( 4 G) to 6 A 1 ( 6 S) transition of the Mn 2+ ion doped in TCP lattice [26]. The inset in Fig.…”

New Y2BaAl4SiO12:Ce3+ yellow microcrystal-glass powder phosphor with high thermal emission stability

“…Intending to develop a new yellow candidate with less rare earth element usage than YAG:Ce, in this paper, we report the Y 2 BaAl 4 SiO 12 :Ce composition artificially created from YAG:Ce by using the solid state design, [15][16][17] where a YO 8 polyhedron is…”