Spectral properties of Eu3+-activated yttrium oxysulfide red phosphor

Abstract

The effects of Eu on the spectral properties of Y2O2S have been investigated. The Y2O2S:Eu phosphor powders were prepared with a flux fusion method and electrophoretically deposited on an ITO-coated glass substrate to form a thin layer. Both cathodoluminescence and photoluminescence emission spectra of Y2O2S:Eu were measured. The highly intense emission lines at 616 and 626 nm are attributed to the transition from D-5(0) to F-7(2) levels. The color of Y2O2S:Eu phosphor varies from orange to red as the Eu concentration increases from Eu/ Y = 0.025 (molar ratio) to 0.06. The luminescence decay times are shorter than 1.1 ms for Eu concentrations ranging from 0.025 to 0.06 (Eu/ Y molar ratio). The luminescent color becomes redder but less bright as the Eu concentration is increased. (C) 1998 Elsevier Science S.A. All rights reserved.