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数理基础与前沿研究论坛--Enhancement of the zero-phonon line intensity as a promising direction towards efficient Mn4+-based red phosphors for white LED applications

发布部门:理学院   发布人:胡锡奎   发布时间:2019年07月10日 11:08

报告题目:Enhancement of the zero-phonon line intensity as a promising direction towards efficient Mn4+-based red phosphors for white LED applications

报告人:Mikhail Brik教授(爱沙尼亚塔尔图大学)

报告时间:2019年07月12日(星期五)上午10:45-11:45

报告地点:理学院三楼会议室(SL310)

报告摘要:

The luminescence of the Mn4+ions in solids has aroused considerable interest since the commercialization of the red emitting K2SiF6:Mn4+(KSF) phosphor for use in a blue LED device. The Mn4+red emission in combination with the blue LED radiation (near 450 nm) and the yellow garnet emission (Y3Al5O12:Ce3+; broad band emission near 580 nm) generates warm white light with high color rendering and brightness.There isconsiderable interest to other Mn-activated host crystals with the aim of developing a LED phosphor of alternate composition. To realize this goal, it is extremely important to understand the fundamental factors governing the Mn4+emission properties in solids, which are as follows: i) degree of covalence of the Mn-ligand bonding; ii) the presence or absence of inversion symmetry at the local site occupied by the Mn4+ion; and iii) the influence of the second coordination sphere around the Mn4+ion. To maximize the phosphor brightness, it is important to place the Mn4+emission spectrum in the narrow wavelength region of 590 nm-650 nm, to increase the overlap with the human eye sensitivity curve. The “host-Mn4+” interaction that induces emission at wavelengths greater than 650 nm will produce phosphor with low brightness or luminosity. A further gain in phosphor luminosity can be achieved by incorporating Mn4+in crystals that enhance the intensity of the Mn4+2Eg4A2gzero phonon transition. Based on our recent publications, a key strategy on how to enhance the zero-phonon line intensity is suggested [1, 2], which can serve as a useful guide in a smart search for new phosphor materials with improved characteristics.

References:

[1] M.G. Brik, S.J. Camardello, A.M. Srivastava, N.M. Avram, A. Suchocki, ECS J. Solid State Sci. & Technol. 5 (2016) R3067-R3077.

[2] D.-X. Liu, C.-G. Ma, P.-W. Hu, Z. Li, Y. Tian, P. Su, M.G. Brik, A.M. Srivastava, S. Tanabe, J. Am. Ceram. Soc. 101 (2018) 2368–2375.

报告人简介:Mikhail Brik是爱沙尼亚塔尔图大学物理所终身教授,香港教育学院荣誉教授,中国国家外专局高端外国文教类专家,重庆市百名海外高层次人才聚集计划获得者,重庆市巴渝引智计划特聘教授,重庆邮电大学特聘外籍专家。其研究兴趣集中在光电子材料物理领域,现已在Journal of the American Chemical Society等国际顶级期刊(多数为中科院分类的1-2区杂志)上发表SCI论文380篇(论文被他引近4000次,H指数32,同时担任35多种材料物理学领域的国际权威杂志如Chemistry of Materials的审稿人),出版7本科研专著,并已在各类国际学术会议上做180个学术报告(其中大会负责委员8次,大会主邀请报告18个)。由于突出的学术成就,其多次获得各种荣誉:2006年获罗马利亚科学院Dragomir Hurmuzescu奖;2008-2013年先后担任香港教育学院荣誉副教授和教授;2013年获得爱沙尼亚国家科学技术成就奖(奖金来自欧盟)。

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