Red luminescence and UV light generation of europium doped zinc oxide thin films for optoelectronic applications

Abstract

In the present work, the Europium doped Zinc Oxide thin films were elaborated using spray pyrolysis technique. We are interested in investigating the structural properties, photoluminescence (PL) and third harmonic generation (THG) of the elaborated films. The structural properties of as-prepared thin films were characterized by X-ray diffraction (XRD). It confirms that all deposited thin films of Europium doped Zinc Oxide are crystallized in the hexagonal wurtzite structure. Both undoped and doped europium thin films show strong preferred c-axis orientation. Photoluminescence (PL) emission from Europium doped Zinc Oxide thin films, under excitation by 266 nm, shows characteristic transitions of Europium (5D0→7F0, 5D0→7F1, 5D0→7F2, …). It reveals the good incorporation of Eu3+ ions in the ZnO host. Additionally, the 5D07F2 is the most intense transition usually observed for Eu3+ embedded in materials of Zinc Oxide lattice. The dependence of third-order nonlinear susceptibility on doping rate was evaluated. The highest nonlinear susceptibility χ3 is obtained for the 5% Europium doped ZnO sample.

First investigation of the effect of strontium oxide on the structure of phosphate glasses using molecular dynamics simulations

“…Moreover, phosphate glasses also have other application fields in the biomaterial field [4][5][6][7][8], such as a solid-state laser source [9][10][11][12] and for vitrification of high-level nuclear waste [13,14]. In addition, the introduction of rare earth in phosphate glasses makes it attractive in the production of optoelectronic devices [15][16][17][18]. However, the phosphate glasses have low chemical durability that provided by the easily hydrated P-O-P bridges leads to their corrosion, induced by water originating, for example, in a humid environment [19,20].…”

Eu3+ Luminescence Enhancement via Bandgap Engineering of Zn1–xMgxO:Eu Epitaxial Thin Films

“…The PLE spectra suggest that the primary excitation mechanism occurs via the generation of excitons and then the transfer of their recombination energy to the core electrons of Eu ions (internal defect Auger recombination) . However, the standard energy transfer model predicts that its efficiency depends, first of all, on the location of the energy levels of defects and dopants in the bandgap, as proposed by other authors for ZnO:Eu. – , Similarly, temperature quenching of the PL of REs via back-transfer of energy depends on the depths of the corresponding levels, according to the model of Favennec et al, , which justifies to some extent low back-transfer efficiency in wide band gap semiconductors. We postulate that this simple model does not adequately explain the Eu PL efficiency dependence on the fractional Mg content in Zn 1– x Mg x O and the PL enhancement is not due to the reduced back transfer but due to excitonic oscillator strength, providing a very efficient excitation pathway.…”

“…It is observed in the samples M4 and O1.25, having a fractional Mg content of about 25% and more, that the Zn 1– x Mg x O:Eu bandgap is high enough to populate the higher energy states of Eu 3+ ions in the alloy host, enabling radiative transitions from excited states such as 5 D 1 , 5 D 2 , and 5 D 3 (Figure c). Emission from Eu 3+ higher excited levels is characteristic in host materials of low phonon energy. , Phonon assisted non-radiative relaxations then take the least amount of energy favoring the activation of Eu 3+ to higher excited states. When the bandgap energy of ZnMgO host increases, more energy is being transferred to Eu 3+ centers.…”

Preparation and Characterization of Nickel and Aluminum-Codoped SnO2 Thin Films for Optoelectronic Applications

“…These studies refer to a class of materials, which present the visible wavelength range, high optical transparency, and high reflectance in the infrared (IR) one with good electrical conductivity of nearly semimetallic regime. These optical and electrical properties make them suitable for several applications such as photocatalysis [1][2][3][4][5], liquid crystal displays [6], photothermal converters [7], transparent electrodes in solar cells [8][9][10], flat panel displays [11], light-emitting diodes [12], heated mirrors [13], gas sensors [14,15], and other optoelectronic devices [16][17][18]. In this work, we will be presenting tin oxide SnO 2 known under the name of cassiterite in natural state, which is crystallized in the tetragonal crystalline structure [7], belonging to the P42/mnm space group [19].…”