Synthesis of GdBO3:Eu3+ nanophosphors via acetylacetone assisted aqueous sol–gel route: Effect of some synthesis parameters

Abstract

Nano-sized Eu 3+ -doped GdBO 3 vaterite type nanophosphors have been synthesized successfully via acetylacetone assisted aqueous sol-gel route. Systematic investigation of the influence of Eu 3+ ion content and pH value of the suspension of precursors on structural, morphological and luminescence spectroscopic properties has been performed. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, field emission-scanning electron microscopy (FE-SEM), Thermogravimetric and differential thermal gravimetry (TG/DTA), room temperature steady and time resolved photoluminescence (PL) spectroscopy techniques were employed to characterize the obtained powder samples. It has been found that the Eu 3+ ion content and pH value precursors suspension have important effect on the structural, morphology and emission properties. The XRD analysis reveals that GdBO 3 : 10% mol Eu 3+ synthesized at pH = 2 and pH = 10 exhibit the quasi-purest P6 3 /mmc vaterite structure. The vibrational absorption of (BO 3 ) 3group is assigned to the GdBO 3 with calcite type or other vaterite structure namely triclinic and monoclinic. The morphologies of GdBO 3 particles size increases with increasing of pH value. All sample present only the orange-red colors emission from 5 D 0 levels to the 7 F J levels (J = 0-3) of Eu 3+ ion. Furthermore, it was found that 10% concentration of Eu 3+ presents the quenching of emission in GdBO 3 . Also, it was that the emission intensity was affected by the pH value and sample with pH = 10 exhibits the highest emission intensity. The asymmetry ratio parameter R between red M. Seraiche a, *

High quantum efficiency and excellent color purity of red-emitting Eu3+-heavily doped Gd(BO2)3-Y3BO6-GdBO3 phosphors for NUV-pumped WLED applications

“…48 The most intense PL intensity is obtained at 20 mol%, indicating that the distance between neighbor Eu 3+ ions reached its critical distance threshold, R c . 8,11,48 In this case, the R c value of 7.02 Å can be determined using the Blasse equation, which is higher than the critical value of 5 Å for exchanging energy by interaction, implying the governance of the multipolar interaction for the quenching mechanism. 8,16 It is well known that multipolar interaction oen contains three types that correspond to the value of the characteristic function for multipolar interaction types: dipole-dipole, dipole-quadrupole, and quadrupolequadrupole interactions.…”

“…8 Then, it decreases with higher concentrations from 20 to 35 mol% Eu 3+ , possibly relating to the quenching effect of concentration. 48 The most intense PL intensity is obtained at 20 mol%, indicating that the distance between neighbor Eu 3+ ions reached its critical distance threshold, R c . 8,11,48 In this case, the R c value of 7.02 Å can be determined using the Blasse equation, which is higher than the critical value of 5 Å for exchanging energy by interaction, implying the governance of the multipolar interaction for the quenching mechanism.…”