Multi-wavelength excited white-emitting K₂Gd_(1−x)(PO₄)(WO₄):xDy³⁺ phosphors with satisfactory thermal properties for UV-LEDs

Abstract

Luminescent multi-wavelength excited K2Gd(1−x)(PO4)(WO4):xDy3+ phosphors have excellent thermal stability and warm white emissions.

Crystal growth, layered structure and luminescence properties of K2Eu(PO4)(WO4)

“…At the same time, the presence of peak positions' shifts in the PL excitation spectra, complex dependence of the asymmetry ratio R on excitation wavelength, and two components observed in kinetics of the PL decay cannot be omitted and requires additional study. Similar situation has been observed for other Eu-containing compounds where defects in oxygen environment of europium 35–40 caused by annealing during synthetic procedure leads to distinguish two types of luminescence centers. The first one is associated with Eu in regular EuO 8 dodecahedra, while the second center may be related with oxygen vacancies.…”

“…This phenomenon is not typical for Eu 3+ ions emission in solids but it has been observed earlier for some hosts, in particular phosphate and tungstate ones. [35][36][37][38] High intensity of the 5 D 0 / 7 F 4 transitions was explained earlier assuming the highly polarizable chemical environment for Eu 3+ emission centre. 32 In our case, the europium cations are surrounded by 4 phosphate and 2 tungstate tetrahedra (Fig.…”

Effect of anionic group [SiO4]4−/[PO4]3− on the luminescence properties of Dy3+-doped tungstate structural compounds

“…In the practical applications of high-power solid state lighting, thermal stability is an important parameter to be considered [30][31][32]. So the thermal stability of the as-obtained Li 2 Ca(WO 4 ) 2 :0.08Dy 3+ , Li 2 Ca 2 (WO 4 )(SiO 4 ): 0.08Dy 3+ , and LiCa 2 (WO 4 )(PO 4 ):0.08Dy 3+ samples was evaluated according to their temperature dependence.…”

Dual-Mode Manipulating Multicenter Photoluminescence in a Single-Phased Ba9Lu2Si6O24:Bi3+, Eu3+ Phosphor to Realize White Light/Tunable Emissions

“…It is accepted that the thermal stability of a phosphor is of great significance for its practical applications, including the color rendering index and the light output of w-LEDs 30 . Therefore, Fig.…”