Synthesis and photoluminescence study of narrow-band UVB-emitting LiSr₄(BO₃)₃:Gd³⁺, Pr³⁺ phosphor

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• 作者：A O CHAUHAN ; N S BAJAJ ; S K OMANWAR
• 关键词：Inorganic borate ; SEM ; photoluminescence ; narrow ; band UVB ; energy transferred.
• 刊名：Bulletin of Materials Science
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：40
• 期：1
• 页码：1-6
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Materials Science, general; Engineering, general;
• 出版者：Indian Academy of Sciences
• ISSN：0973-7669
• 卷排序：40

文摘

A series of Pr3+, Gd3+ and Pr3+–Gd3+-doped inorganic borate phosphors LiSr₄(BO₃)₃ were successfully synthesized by a modified solid-state diffusion method. The crystal structures and the phase purities of samples were characterized by powder X-ray diffraction. Surface morphology of the sample was studied by scanning electronic microscopy (SEM). The optimal concentrations of dopant Gd3+ ions in compound LiSr₄(BO₃)₃ were determined through the measurements of photoluminescence (PL) spectra of phosphors. Gd3+-doped phosphors LiSr₄(BO₃)₃ show strong band absorption in UV spectral region and narrow-band UVB emission under the excitation of 276 nm was only due to 6P_J → 8S_7/2 transition of Gd3+ ions. The effect of Pr3+ ion on excitation of LiSr₄(BO₃)₃:Gd3+ was also studied. The excitation of LiSr₄(BO₃)₃:Gd3+, Pr3+ gives a broad-band spectra, which show very good overlap with the Hg 253.7 nm line. The photoluminescence spectra of LiSr₄(BO₃)₃ with different doping concentrations Pr3+ and keeping the concentration of Gd3+ constant at 0.03 mol have also been studied. The emission intensity of LiSr₄(BO₃)₃:Pr3+–Gd3+ phosphors increases with increasing Pr3+ doping concentration and reaches a maximum at 0.01 mol. From the photoluminescence study of LiSr₄(BO₃)₃:Gd3+, Pr3+ we conclude that there was efficient energy transfer from Pr3+→ Gd3+ ions in LiSr_4−x−yPr_xGd_y(BO₃)₃ phosphors.