Zinc Phosphate Glasses Doped Yttrium-Europium Oxide, a Luminescence Study

Abstract

Zinc phosphate glasses doped with yttrium-europium oxide, were obtained by melting at 1100 °C; suitable precursors of these glasses quantities was grinded mechanically and dried at 400 °C for 2hrs, then the temperature was raised to 800 °C for 2hrs again, finally the temperature was raised at 1100 °C for 3hrs until a liquid is achieved, this liquid is emptied in a copper block to produce a thermal shock and observe the formation of a glass; a final heat treatment at 300°C for 12hrs is practiced. Luminescent studies were conducted in these glasses, it is observable, that when excited with λexc = 396nm are present the 5D0 to 7F1, 7F2, 7F3 y 7F4 transitions in 590, 616, 650, and 697 nm; the main emission is achieved at 616 nm and a high red light emission is observable at naked eye, due to the presence of europium ions. Absorption spectra, transmission and reflectance are obtained; these glasses are transparent in the region of 400 nm to 1100 nm UV; XRD indicates that samples are amorphous; the emission spectra of these glasses were doped with different amounts of yttrium-europium oxide; they depend on the amount of dopant. The luminescent properties of Y2O3:Eu3+ powders have been studied, luminescent Y2O3:Eu3+ polycrystalline powders were synthesized by a simple evaporation method. The photoluminescence and cathodoluminescence emission spectra these samples show, luminescence peaks associated with transitions within the electronic energy levels of Eu3+ ions. The dominant peak is at 612nm corresponding to the 5D0 to 7F2 transition and present 5D0 to 7F1, 7F2, 7F3 y 7F4 transitions in 590, 616, 650, and 697 nm, when excited with λexc = 260 nm and λexc= 396at room temperature. The intensity luminescence Y2O3:Eu3+ powders with different dopant concentrations, Eu3+ ion dependent percentage, finding the optimal concentration is 17 mol%. XRD of powders Y2O3:Eu3+ show these correspond to space group: Ia-3(206), with Cell: 10.6039 10.6039 10.6039 90.000 90.000 90.000, Volume: 1192.328 and whit Crystal System: Cubic (No: 01-075-3096); these powders were evaporated at 200 °C and then calcined for two hours at 1100°C. EDS analysis shows that the corresponding Y2O3:Eu3+ powders, showing that the achieved yttrium is stoichiometric according to general Y2O3 formula. According to the results of the photoluminescence of these powders Y2O3: Eu3+, to excite λexc = 396nm have the energy required for luminescence is less and therefore can obtain low-cost LEDs for red light; so it can be considered that this type of compound is a good candidate to have red light and its preparation is simple and inexpensive.