Optical properties of Mn⁴⁺-activated Na₂SnF₆ and Cs₂SnF₆ red phosphors

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• 作者：Yusuke Arai^a ; Sadao Adachi ; ^a ; ^{adachi@el.gunma-u.ac.jp"" rel=""nofollow}
• 关键词：Red phosphor ; Na₂SnF₆ ; Cs₂SnF₆ ; K₂SiF₆ ; K₂TiF₆ ; Hexafluorometallate
• 刊名：Journal of Luminescence
• 出版年：2011
• 出版时间：December 2011
• 年：2011
• 卷：131
• 期：12
• 页码：2652-2660
• 全文大小：1220 K

文摘

Alkaline hexafluorostantanate red phosphors Na₂SnF₆:Mn⁴⁺ and Cs₂SnF₆:Mn⁴⁺ are synthesized by chemical reaction in HF/NaMnO₄ (CsMnO₄)/H₂O₂/H₂O mixed solutions immersed with tin metal. X-ray diffraction patterns suggest that the synthesized phosphors have a tetragonal symmetry with the space group D_4h¹⁴ (Na₂SnF₆:Mn⁴⁺) and a trigonal symmetry with the space group D_3d³ (Cs₂SnF₆:Mn⁴⁺). Photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and the Raman scattering techniques are used to investigate the optical properties of the phosphors. The Franck–Condon analysis of the PLE data yields the Mn⁴⁺-related optical transitions to occur at 2.39 and 2.38 eV (⁴A_2g→⁴T_2g) and at 2.83 and 2.76 eV (⁴A_2g→⁴T_1g) for Na₂SnF₆:Mn⁴⁺ and Cs₂SnF₆:Mn⁴⁺, respectively. The crystal field parameters (Dq) of the Mn⁴⁺ ions in the Na₂SnF₆ and Cs₂SnF₆ hosts are determined to be 1930 and 1920 cm⁻¹, respectively. Temperature-dependent PL measurements are performed from 20 to 440 K in steps of 10 K, and the obtained results are interpreted by taking into account the Bose–Einstein occupation factor. Comprehensive discussion is given on the phosphorescent properties of a family of Mn⁴⁺-activated alkaline hexafluoride salts.