Electronic structure and optical properties of europium-activated yttrium oxide phosphor

Abstract

The electronic structure and optical properties of a red phosphor, Y203.Eu, have been studied using the first-principles molecular-orbital and band-structure methods. Using the calculated one-electron energy levels, several properties of the host material and properties of the phosphor based on host-impurity interactions have been explained. However, it has been found that the luminescence properties of Eu + require the spin-orbit effects to be included in the computational methods.

Enhanced luminescence from spontaneously ordered Gd2O3:Eu3+ based nanostructures

“…It was found that the full width at half maximum (FWHM) decreases almost 50% for films annealed at 973 K, when lithium doping was done. This is an indication of the better crystallization and larger grain size and can be regarded as a result of the flux effect of Li + ions during the growth process, which plays a role in effective promotion of the incorporation of Eu 2 O 3 and Gd 2 O 3 as well as Li + ions themselves into the host lattice [36].…”

“…Among these factors composition could be one of the lead breakthroughs for increased brightness of Gd 2 O 3 :Eu 3+ thin films. It is well known that even in very small quantities, the Li + coactivators frequently play an important role in the enhancement of the luminescent efficiency of phosphors [4,19]. Yi [19][20][21].…”

“…Many authors have used rare-earth doped oxide particles as phosphors in various display applications such as field emission displays (FEDs) [1], plasma display panels (PDPs) [2], cathode ray tubes (CRT) [3], and more. Lanthanide activated rare-earth oxides [4,5] remain as promising materials for next generation display technology because of several essential superior properties such as luminescent characteristics, stability in vacuum and corrosion free gas emission under electron bombardment compared with traditional cathode ray tube red phosphors used in current field emission displays [6,7]. The field emission display have gained a great interest and have been recognized as one of the most promising technologies in flat panel display market due to their most important features like great brightness, wide horizontal and vertical view angles, good contrast ratio, high efficiency with low power consumption, short response time and wide work temperature range [8][9][10][11][12].…”

Photoluminescence in Low-Dimensional Oxide Ferroelectric Materials

“…Photoluminescence spectra of the thin films included two strong peaks which originated from two transitions of 5 D 0 → 7 F 1 (594 nm) and 5 D 0 → 7 F 2 (617 nm) of levels of Eu 3+ ions [38,39]. The emission peak intensities of the two transitions increase with increasing annealing temperature, due to improved crystallinity of the thin films, resulting in higher oscillating strengths for optical transitions [40,41]. At higher temperature, Eu 3+ ions can arrive at real lattice sites more easily, thus this leads to enhanced activation of Eu 3+ ions [42].…”

“…The polarization enhancement by La 3+ substitution can be attributed to crystallization improvement of the thin films which has been confirmed by XRD and SEM. In addition, better crystallinity can also result in strong photoluminescence due to higher oscillating strengths for the optical transitions [41].…”