Structure and luminescence properties of the novel multifunctional K2Y(WO4)(PO4):Ln3+ (Ln = Tb, Eu, Yb, Er, Tm and Ho) phosphors

Abstract

Lanthanide ions (Tb, Eu, Yb, Tm, Er, and Ho) activated multifunctional phosphors K 2 Y(WO 4 )(PO 4 ), (KYWP) were prepared via a conventional solid-state reaction. The crystal structure of KYWP as a new host matrix for luminescence was firstly defined to be the orthorhombic system with space group Ibca (73) via Rietveld refinement of the powder X-ray diffraction (XRD) and the GSAS software. The vacuum ultraviolet (VUV) excited photoluminescence and cathodoluminescence (CL) analysis of individual 10 Tb 3+ /Eu 3+ activated KYWP phosphors exhibit excellent emission properties in their respective regions. Both KYWP: Tb 3+ and KYWP: Eu 3+ had high quenching concentration under 147 nm excitation attributed to a long Y-Y distance in KYWP structure, whereas they showed very low quenching concentration under low-voltage electron-beam excitation. This phenomenon was ascribed to the different mechanisms between CL and VUV excited luminescence. Under 980 nm laser excitation, yellow, purple, 15 and red up-conversion (UC) emissions had been achieved in Yb 3+ -Er 3+ , Yb 3+ -Tm 3+ , and Yb 3+ -Ho 3+ codoped KYWP, respectively. In Yb 3+ -Tm 3+ -Ho 3+ tridoped KYWP, red emissions emerging from transitions of Tm 3+ changed to the transitions of Ho 3+ . And the possible reason had been elucidated by a cross-relaxation process between Tm 3+ and Ho 3+ . Laser power dependence of the UC emissions and the energy level diagrams were studied to understand the UC and cross-relaxation mechanisms. The obtained 20 results indicated that the multifunctional lanthanide ions doped KYWP exhibited excellent VUV photoluminescence, CL and multicolor UC luminescence properties. 65 Generally, FEDs operate at a low voltage (≤ 5 kV) and high current density (10 -100 mA·cm -2 ), implying that the phosphors for FEDs are required to have high efficiency at low voltages, high resistance to current saturation and long service time. [20][21][22] Although many efficient sulfide-based compounds such as 70

Synthesis of Eu3+-activated BiOF and BiOBr phosphors: photoluminescence, Judd–Ofelt analysis and photocatalytic properties

“…Trivalent europium ions exhibited narrow band emissions, long lifetimes and large Stokes shis (emission of lower energy radiation upon excitation by higher energy radiation). 7 Various inorganic phosphors have been reported, including molybdates, 7 silicates, 8 phosphates, 9 tungstates, 10 aluminates, 11 nitrides 12 and suldes. 13 These materials are either chemically unstable, expensive or have low uorescent lifetime.…”

Plant habitat-conscious white light-emitting devices: Dy3+-emission considerably reduces involvement in photosynthesis

“…All the diffraction peaks were indexed to an orthorhombic unit cell. The KYWP:Dy peak positions were derived from the unsubstituted K 2 Y(WO 4 )(PO 4 ) 29 structure, and a peak shift was observed resulting from the Dy-substitution. A Rietveld refinement of K 2 Y 0.97 Dy 0.03 (WO 4 )(PO 4 ) was carried out (Fig.…”

Enhanced luminescence properties and energy transfer in Ce3+ and Tb3+ co-doped NaCaBO3 phosphor

“…In recent years, much research effort has been directed towards the synthesis of rare-earth (RE 3 þ ) doped functional materials since they can be used as highly efficient phosphors, catalysts, and optics materials by virtue of their unique optical, electronic, and chemical properties [1][2][3][4]. For applications involving NUV excitation (300-400 nm) for the generation of a variety of display panels, Tb 3 þ ion is a well-known activator that effectively emits green light in diverse host lattices.…”