Electronic structure and luminescence properties of Tb³⁺-activated NaBaBO₃ green-emitting phosphor

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• 作者：Jianghui ZHENG ((閮戝皢杈?)^a ; Qijin CHENG ((绋嬪叾杩?)^a ; Shunqing WU ((鍚撮『鎯?)^b ; Rong CHEN ((闄?钃?)^a ; Lihan CAI ((钄′附鏅?)^a ; Chao CHEN ((闄?鏈?)^a ; ^b ; ^{cchen@xmu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：phosphor ; first principle ; luminescence ; borate ; Tb3+ ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2015
• 出版时间：September 2015
• 年：2015
• 卷：33
• 期：9
• 页码：933-938
• 全文大小：1434 K

文摘

A novel green-emitting phosphor Tb³⁺ doped NaBaBO₃ was prepared using a conventional high temperature solid-state reaction method. The crystal structure and luminescence properties of NaBaBO₃:Tb³⁺ were studied. The NaBaBO₃ host was also investigated using density functional theory calculations. Our calculated lattice parameters of NaBaBO₃ host were found to be in excellent agreement with experiment. Theoretically, the host matrix NaBaBO₃ was a wide-gap semiconductor with a direct band gap of 3.66 eV, where the bottom of conduction band and the top of valence band were dominated by Ba 5d state and O 2p state, respectively. The excitation spectra indicated that the phosphor could be effectively excited by near ultraviolet light. The phosphor featured a satisfactory green performance with the highest photoluminescence intensity located at 543 nm excited by 377 nm light and the measured Commission Internationale de L'Eclairage (CIE) chromaticity was determined to be (0.2860, 0.4640). The optimum Tb³⁺ concentration in NaBaBO₃ was 5.0 mol.%. The concentration quenching occurred when Tb³⁺ concentration was beyond 5.0 mol.% and the concentration quenching mechanism could be explained by the dipole-dipole interaction. The effects of charge compensators (including Li⁺, Na⁺ and K⁺) and temperature on the photoluminescence of NaBaBO₃:Tb³⁺ were also studied. The present work suggested that the NaBaBO₃:Tb³⁺ phosphor was a promising green-emitting material for near ultraviolet white light-emitting diodes.