Metal Hydrides as Novel Host Lattices for the Luminescence of Divalent Europium

金属氢化物作为二价铕发光的新型主体晶格

基本信息

批准号：
238173941
负责人：
Professor Dr. Holger Kohlmann
金额：
--
依托单位：
Institut für Anorganische Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/238173941?language=en
关键词：
Metal Hydrides Novel Host Lattices

项目摘要

Divalent europium doped into inorganic host lattices shows exceptional luminescence properties and is therefore of great interest for applications as a phosphor. Compounds such as oxides, halides, phosphates and silicates have been extensively studied as host material, in which Eu(II) usually shows blue or green emission. Eu(II) doped nitrides have more recently been shown to exhibit yellow to orange emission. Very recently we have investigated metal hydrides for the first time as host lattice for Eu(II) luminescence and found red emission, i. e. the largest redshift ever observed in such compounds. We attribute the large redshift to the polarizability and apparently high ligand field strength of the hydride ion. Further we found very bright yellow emission in the cubic perovskite LiSrH3:Eu2+. Metal hydrides seem therefore to be an interesting class of compounds as novel host materials. This project is about further exploring this potential for Eu(II) luminescence. In particular the influence of the host lattice on the position and splitting of the Eu2+ 5d levels shall be investigated in order to understand luminescence intensities, life times or luminescence quenching. Suitable hosts for europium doping include perovskites LiMH3 (M = Sr, Ba, Sr1-yBay), MMgH4 (M = Sr, Ba) and KMgH3. These materials will be doped with different amounts of europium (0.1-2%) and characterized by X-ray diffraction, neutron diffraction and luminescence spectroscopy, including very high resolution spectra, low temperature and measurements of lifetime and quantum efficiency. We will further take advantage of the hydride-fluoride analogy by trying to synthesize solid solutions of these hydrides with the analogous fluorides, such as LiMHnF3-n:Eu2+ (M = Sr, Ba) or KMgHnF3-n:Eu2+. If the hydride-fluoride ratio can be continuously varied, we should be able to tune the emission wavelength of the Eu(II) doped mixed hydride-fluoride over a wide range, because the fluorides show emission in the blue or green while hydrides show emission in the yellow or red. In addition recently developed synthesis methods will be used to reinvestigate the crystal structure of known metal hydrides, e. g. SrMgH4, which we can now prepare single phase, and to attempt preparation of new host lattices like in the systems KMgH3-M(II)MgH4 with M(II) = Sr, Ba or Sr1-yBayMgH4. On preparing and characterizing the above described europium doped metal hydrides we hope to elucidate the factors governing Eu(II) emission in this new class of host lattices and explore their potential as luminescent materials.

掺杂到无机主晶格中的二价铕显示出优异的发光性能，因此作为荧光粉的应用受到极大关注。氧化物、卤化物、磷酸盐和硅酸盐等化合物作为主体材料已被广泛研究，其中Eu(II)通常显示蓝色或绿色发射。最近，Eu(II) 掺杂氮化物显示出黄色至橙色发射。最近，我们首次研究了金属氢化物作为 Eu(II) 发光的主晶格，并发现了红色发射，即。 e.在此类化合物中观察到的最大红移。我们将大的红移归因于氢负离子的极化性和明显高的配体场强度。此外，我们在立方钙钛矿 LiSrH3:Eu2+ 中发现了非常明亮的黄色发射。因此，金属氢化物似乎是一类有趣的新型主体材料化合物。该项目旨在进一步探索 Eu(II) 发光的潜力。特别是应研究主晶格对 Eu2+ 5d 能级的位置和分裂的影响，以了解发光强度、寿命或发光猝灭。适合铕掺杂的主体包括钙钛矿 LiMH3 (M = Sr, Ba, Sr1-yBay)、MMgH4 (M = Sr, Ba) 和 KMgH3。这些材料将掺杂不同量的铕（0.1-2%），并通过 X 射线衍射、中子衍射和发光光谱进行表征，包括极高分辨率光谱、低温以及寿命和量子效率的测量。我们将进一步利用氢化物-氟化物类比，尝试合成这些氢化物与类似氟化物的固溶体，例如 LiMHnF3-n:Eu2+ (M = Sr, Ba) 或 KMgHnF3-n:Eu2+。如果氢化物-氟化物比例可以连续变化，我们应该能够在很宽的范围内调节Eu(II)掺杂混合氢化物-氟化物的发射波长，因为氟化物显示蓝色或绿色发射，而氢化物显示发射波长黄色或红色。此外，最近开发的合成方法将用于重新研究已知金属氢化物的晶体结构，例如金属氢化物。 g。 SrMgH4，我们现在可以制备单相，并尝试制备新的主晶格，例如 KMgH3-M(II)MgH4 系统，其中 M(II) = Sr、Ba 或 Sr1-yBayMgH4。在制备和表征上述铕掺杂金属氢化物时，我们希望阐明控制这类新型主晶格中Eu(II)发射的因素，并探索它们作为发光材料的潜力。