High Thermal Stability Apatite Phosphors Ca2La8(SiO4)6O2:Dy3+/Sm3+ for White Light Emission: Synthesis, Structure, Luminescence Properties and Energy Transfer

Abstract

What ideal w-LED phosphors always aim to do is to achieve a single phase near-sunlight emission phosphor simultaneously with both high luminescence efficiency and high thermal stability at operation temperature. And It is well known that apatite compound phosphors are one of the most promising optical materials to realize those above because of their unique structure enhanced luminescence properties and thermal stability. Here, we synthesized a co-doped single phase apatite phosphors Ca2La8(SiO4)6O2:Dy3+/Sm3+ (CLSO:Dy3+/Sm3+) for white light emission, which was provided with excellent thermal stability and of which luminescence intensity at 150 °C still was 92 percentage of that at room temperature. Moreover, X-ray diffraction technique, Fourier transform infrared spectroscopy, scanning electron microscope were employed to characterization of phase structure and morphology, and consequently pure apatite structure and gravel-like morphology of phosphors were proved. Analysis of photoluminescence spectra indicated that concentration quenching effect exist in single-doped CLSO:Dy3+ phosphors owing to dipole-dipole interaction between Dy3+ ions. It is revealed that maybe exist Dy3+ ↔ Sm3+ bilateral non-radiative energy transfer processes in Dy3+/Sm3+ co-doped CLSO system by PL spectra and decay curves. And variation of Sm3+ ion concentration can control color emission, namely CIE chromaticity coordinates and correlated color temperature, finally to achieve white light emission (0.309,0.309) with CCT 6848 K, able to be a potential candidate for commercial lighting applications.

Narrow-band red phosphors of high colour purity based on Eu3+-activated apatite-type Gd9.33(SiO4)6O2

“…24 Its suitability as a host has already been reported in studies of white-emitting phosphors. [25][26][27][28][29][30][31][32] The series of red phosphors prepared in this work adopt the general formula Gd 9.33Àx Eu x (SiO 4 ) 6 O 2 (with x = 0.03, 0.05, 0.07, 0.09, 0.19, 0.28, 0.47, 0.65, 0.93, 1.40 and 1.87, corresponding to a maximum of 20 at% Eu 3+ doping). Variable temperature powder X-ray diffraction (PXRD) and optical measurements were used to probe the structural and luminescence behaviour of the materials, with the aim of investigating concentration and thermal quenching, emission efficiency and colour purity.…”

Unraveling the site-specific energy transfer driven tunable emission characteristics of Eu3+ & Tb3+ co-doped Ca10(PO4)6F2 phosphors

“…O 2À , OH À and halogen ions), possess high chemical and thermal stability and considered as an efficient host to develop a variety of phosphor materials with high luminescence efficiency. [5][6][7] Due to their high thermal, chemical and radiation stability such matrices are even potential candidate as host for immobilization of hazardous and highly radioactive nuclear waste. 8,9 Among them the uorapatite based compounds with formula M 10 (PO 4 ) 6 F 2 , (where M ¼ Ca, Sr, Ba etc.)…”

Investigation of Physicochemical Properties of the Structurally Modified Nanosized Silicate-Substituted Hydroxyapatite Co-Doped with Eu3+ and Sr2+ Ions

“…There is particular interest in the characterization of nanoapatite materials doped with optically active ions. Consequently, it is possible to successfully replace Ca 2+ ion by Eu 3+ [1,4,5], Ce 3+ [6], Tb 3+ [7], Dy 3+ [8,9], Nd 3+ [9,10], Sm 3+ [8,9] ions to obtain materials with characteristic emission in red [1,4], green [11,12], violet [6] as well as blue [6] spectral regions. Recently, the apatite matrix has been the focus of attention and investigated in terms of white light emission.…”

“…Recently, the apatite matrix has been the focus of attention and investigated in terms of white light emission. Promising materials are co-doped with Dy 3+ , Li + and Eu 3+ [13] or La 3+ , Dy 3+ and Sr 3+ ions [8]. The vast number of possibilities and favorable results encourage the detailed investigation of a variety of apatite modifications.…”