Enhancement of Emission Intensity in Dy3+-Doped ZnO/ZnF2 Phosphoborate Glasses for W-LED Materials. (September 2019) - Meejitpaisan, P
Abstract: Presently, white light emitting diodes (W-LEDs) were be used to substitute for conventional incandescent and fluorescent lamps due to their advantages; thus, it gets attention to create Dy 3+ -doped zinc phosphoborate glasses for enhancing better lightness. In this research, the replacing of ZnO by ZnF2 in 49B2 O3 :30P2 O5 :(20-x)ZnO:xZnF2 :1Dy2 O3 glasses, 0 ≤ × ≤ 20 mol% were prepared by melt quenching method and investigated through optical absorption and photoluminescence properties. The absorption results can be used for calculating the Judd-Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) and led to predicting the stimulated emission in present glasses. The trend of JO parameters is found to be Ω2 > Ω4 > Ω6 for all glasses. Nevertheless, replacing of ZnF2 does not affect position and intensity of optical absorption of Dy 3+ -doped glasses, whereas the observed blue (481 nm), yellow (573 nm) and red (662 and 752 nm) emission intensities of photoluminescence spectra rise with ZnF2 contents; the emission intensity at 573 nm for 20ZnF2 show the highest and was higher than 20ZnO around 1.6 times. The emission color of Dy 3+ -doped zinc phosphoborate glasses has been evaluated with CIE 1931 chromaticity diagram. The results revealed that all glasses emit white light. Hence, these glasses may be suitable candidate for using in W-LED and lighting materials.