The synthesis and luminescence properties of a novel red-emitting phosphor: Eu3+-doped Ca9La(PO4)7

Orange‐Red‐emitting Ca9Gd(PO4)7:Eu3+ Phosphors: Judd‐Ofelt Analysis and Investigation on the Thermal Stability, Quantum Efficiency for WLED

“…Previously, Zehui et al. reported that a high (R 21 >1) or low (0<R 21 <1) value of hypersensitive ratio means an asymmetry or symmetry sites around Eu 3+ ions, respectively [40] . Thus, the calculated values of R 21 between 1.65 and 1.89 in our experiment strongly demonstrated that Eu 3+ ions mostly locate in the asymmetry sites in the host lattice.…”

“…In addition, commission International De l'Eclairage (CIE 1931) chromaticity diagram has been prevalently employed to illustrate the chromatic characterization of phosphor luminescence [23,54,58,59] . For being excited by the 394 nm, the chromaticity‐coordinates (x; y) of the Ca 9 Gd(PO 4 ) 7 :7 %Eu 3+ phosphor (0.5849; 0.3635) is shown in Figure 9, which is comparable with those of commercial red phosphors, such as Y 2 O 3 :0.05 %Eu 3+ (0.65; 0.34), [3] Ca 9 La 0.40 Eu 0.60 (PO 4 ) 7 (0.64; 0.36) [40] and Ca 9 Gd(PO 4 ) 7 : 0.9 %Eu 3+ (0.6029; 0.3561) [23] . As presented in Table 3, it is also noticed that the chromatic coordinate values (x; y) of all Ca 9 Gd(PO 4 ) 7 :Eu 3+ samples doped with different Eu 3+ concentrations are approximately similar.…”

“…With the Eu 3+ ions concentration of from 1 to 10 %, the maximum PL intensity is obtained at the doped‐Eu 3+ ions level of 7 %. The decrease of the PL intensity at the high doping concentration of 10 % could be due to concentration quenching effect [23,39–41] . It is reported that the particular mechanism of the quenching phenomenon in the photoluminescence intensity could be interpreted by studying the effective energy transfer through this critical distance (R c ) which could be estimated by this equation 2 [42–45] …”

Structural and photoluminescence properties of Dy3+‐activated NaCaPO4 phosphor derived from solution combustion

“…[ 11 ] Over the past two decades, progress has been observed in the synthesis and characterization of lanthanide‐activated phosphate‐based phosphors, largely due to the suitability and adaptability of phosphate‐based phosphor materials in solid‐state lighting. [ 12,13 ] As published previously, phosphate‐based luminescent materials have excellent chemical and thermal stabilities. In particular, ABPO 4 (A = K, Li, Na; and B = Ca, Mg, Sr)‐based phosphors have been widely studied for WLED applications, exhibiting superior luminescence properties.…”

Warm‐white light performance of Dy3+, Eu3+: NaLa(WO4)2 phosphors excited with a 450‐nm LED

“…It is well known that rare earth ions have a large number of energy levels and excited wavelengths suitable for ultravisible light. The Eu 3+ ion is an important activator due to its red emission band corresponding to the transition of 5 D 0 → 7 F 0‐4 . The typical ultraviolet excited wavelengths for the Eu 3+ ion are 365 and 395 nm, which are widely used in commercial LEDs and correspond to the transition of 7 F 0 → 5 D 4, 5 L 6 .…”