Synthesis of Al₂O₃: Eu³⁺Powder and PET Films with this Powder Incorporated: A Luminescence Study

Abstract

Luminescent properties of Al 2 O 3 :Eu 3+ powder and polyethylene therephtalate (PET) films with this powder incorporated in them are reported. Powders were synthesized by simple evaporation method and the polymeric thin films were made by spray pyrolysis technique using recycled PET as raw material. The phosphors were characterized by cathode and photoluminescence techniques; in both cases, the luminescence spectra peaks observed are associated with inter level transitions within the electronic energy states of Eu 3+ ions ( 5 D 0 to 7 F 1 , 7 F 2 , 7 F 3 y 7 F 4 , located at 590, 616, 650, and 697 nm, respectively). Powders spectra show higher luminescence intensity than those intensities observed for films. The dominant peak intensity is associated with the 5 D 0 to 7 F 2 transition at 616 nm. XRD measurements of the powder phosphors show that they are polycrystalline. PET films are transparent (between 80 and 95%T in the UV-Vis range).In recent years most of the work on the Flat Panel Displays (FPD) area has been focused to the development of metal oxide based luminescent films of high quality, that can be used as optically active layers in photoluminescent, cathodoluminescent and electroluminescent devices, for this purpose it is necessary to obtain flat and transparent films in order to obtain a device with a good resolution, contrast and efficiency characteristics. More recently other properties and characteristics like flexibility, low cost, lightness and environmental friendly have caused an increasing interest.Metal oxides are attractive host materials for rare earth dopants to develop advanced phosphors due to their good stability and easiness to synthesize. 1-3 Trivalent rare-earth doped oxides are some of the most promising phosphors; their 4f n valence clouds are shielded by the 5s 2 p 6 electron cloud and according to this electron configuration, the sharp lines due to the f-f transitions are observed in the optical absorption and emission spectra. 4,5 Among rare earth ions, Eu 3+ ions have attracted significant attention because they have tremendous potential for applications in some optical fields, such as phosphors, electroluminescent devices, and optical amplifiers or lasers. 6-8 In addition, the luminescence of Eu 3+ ions is particularly interesting because the emission corresponding to the 5 D 0 to 7 F 2 transition, centered near 612 nm, provides one of the three fundamental colors (red, blue, and green).Among the materials investigated to date, a few experiments have been performed on rare-earth ion doped aluminum oxide (Al 2 O 3 ). [8][9][10][11][12][13][14] The Al 2 O 3 crystal is a material with a significant technological importance because of the large optical transparency from ultraviolet to near-infrared, and because of its excellent mechanical properties and good chemical stability. Several crystalline phases of Al 2 O 3 are known, the α -Al 2 O 3 is the most stable phase. These rare earth doped Al 2 O 3 materials have been synthesized by techniques such as sol-gel, ion beam implantat...

Up and Down Conversion Photoluminescence from Er, Yb and Li Doped Y2O3Phosphors and Composites Films with PMMA

“…17,23 In this easy scalable technique, the precursor compounds dissolved in a proper solvent are heated until its solvent evaporation point to achieve a powder. A thermal treatment is also given to this powder in order to eliminate any kind of remnant from the precursor materials and/or to achieve an appropriate crystalline structure.…”

“…Phosphors synthesis.-Luminescent Y 2 O 3 powders were prepared by the solvent evaporation method; this technique is an inexpensive, atmospheric pressure process that has been used to obtain powders of different materials, mainly metal oxides. 17,23 In this easy scalable technique, the precursor compounds dissolved in a proper solvent are heated until its solvent evaporation point to achieve a powder. A thermal treatment is also given to this powder in order to eliminate any kind of remnant from the precursor materials and/or to achieve an appropriate crystalline structure.…”

“…Nowadays, obtaining z E-mail: ehuerta@cinvestav.mx materials in the form of coatings with properties like mechanical flexibility, environment friendly and low manufacturing cost; is becoming important. Polymer films offer all these properties and some of them can be synthesized to have luminescent properties [16][17][18] through RE doping. These films have been sensitized by many techniques such as: spin-coating, sol-gel, spray pyrolysis and MAPLE (matrix assisted pulsed laser evaporation) among others.…”

Effect of low-density polyethylene on the luminescent properties of thulium-doped yttrium oxide obtained by the polyol technique

“…Either as support of inorganic materials such as terbium doped alumina [10], as a host to several other monomers like polyethylene glycol, pyrene and 7-hydroxycoumarin [11][12][13] or supporting CdS quantum dots [14], polyethylene has proven to be an adequate material for luminescent applications. Our group has used it as support of aluminum oxide doped with terbium and europium [15,16] but, to our knowledge, polyethylene has not been used as a host of luminescent particles of materials such as rare-earth-doped yttrium oxide.…”