Red emitting MTiO₃ (M = Ca or Sr) phosphors doped with Eu³⁺ or Pr³⁺ with some cations as co-dopants

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• 作者：B. Mar铆 ; K.C. Singh ; Paula Cembrero-Coca ; Ishwar Singh ; Devender Singh ; Subhash Ch
• 关键词：CaTiO3 ; Eu3+ ; M+ (Li+ ; Na+ or K+) ; SrTiO3 ; Eu3+ ; CaTiO3 ; Pr3+ ; Charge compensators ; Combustion synthesis
• 刊名：Displays
• 出版年：October, 2013
• 年：2013
• 卷：34
• 期：4
• 页码：346-351
• 全文大小：836 K

文摘

Ca (or Sr)TiO₃:Eu³⁺, M (Li⁺ or Na⁺ or K⁺) and CaTiO₃:Pr³⁺, M (Li⁺ or Na⁺ or Ag⁺ or K⁺ or Gd³⁺ or La³⁺) powders were prepared by combustion synthesis method and the samples were further heated to 鈭?000 掳C to improve the crystallinity. The structure and morphology of materials were examined by X-ray diffraction (XRD) and a scanning electron microscopy (SEM). The morphologies of SrTiO₃:Eu³⁺, CaTiO₃:Eu³⁺ or CaTiO₃:Pr³⁺ powders co-doped with other metal ions were very similar. Small and coagulated particles of nearly cubical shapes with small size distribution having smooth and regular surface were formed. Photo-luminescence spectra of CaTiO₃:Pr³⁺ and co-doped either with Li⁺, Na⁺, K⁺, Ag⁺, La³⁺ or Gd³⁺ ions showed red emissions at 613 nm due to the ¹D₂ 鈫?#xA0;³H₄ transition of Pr³⁺. The variation of intensity of emission peak with different co-doping follows the order: K⁺ > Ag⁺ > Na⁺ > Li⁺ > La³⁺ > Gd³⁺. The characteristic emissions of CaTiO₃:Eu³⁺ lattices had strong emission at 614 and 620 nm for ⁵D₀ 鈫?#xA0;⁷F₂ with other weak transitions observed at 580, 592, 654, 705 nm for ⁵D₀ 鈫?#xA0;⁷F_n transitions where n = 0, 1, 3, 4 respectively in all host lattices. Photoluminescence intensity in SrTiO₃:Eu³⁺ is more than CaTiO₃:Eu³⁺ lattices. A remarkable increase of photoluminescence intensity (in ⁵D₀ 鈫?#xA0;⁷F₂ transition) was observed if co-doped with Li⁺ ions in CaTiO₃:Eu³⁺ and SrTiO3:Eu³⁺.