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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.

掺杂到无机基质晶格中的二价铕显示出优异的发光性质，因此对于作为磷光体的应用具有极大的兴趣。氧化物、卤化物、磷酸盐和硅酸盐等化合物作为基质材料已被广泛研究，其中Eu（II）通常显示蓝色或绿色发射。Eu（II）掺杂的氮化物最近显示出黄色至橙子发射。最近，我们首次研究了金属氧化物作为Eu（Ⅱ）发光的基质晶格，发现了Eu（Ⅱ）的红光发射。e.在这类化合物中观测到的最大红移。我们把大的红移归因于氢化物离子的极化率和明显高的配位场强度。此外，我们在立方钙钛矿LiSrH 3：Eu 2+中发现了非常明亮的黄色发射。因此，金属氧化物似乎是一类有趣的化合物作为新的主体材料。该项目旨在进一步探索Eu（II）发光的潜力。特别是主晶格上的位置和分裂的Eu 2 + 5d能级的影响应进行调查，以了解发光强度，寿命或发光猝灭。用于铕掺杂的合适主体包括钙钛矿LiMH 3（M = Sr、Ba、Sr 1-yBay）、MMgH 4（M = Sr、Ba）和KMgH 3。这些材料将掺杂不同数量的铕（0.1-2%），并通过X射线衍射，中子衍射和发光光谱学进行表征，包括非常高的分辨率光谱，低温和寿命和量子效率的测量。我们将通过尝试合成这些氟化物与类似氟化物的固溶体，如LiMHnF 3-n：Eu 2+（M = Sr，Ba）或KMgHnF 3-n：Eu 2+，进一步利用氟化物的类比。如果可以连续地改变双金属-氟化物比率，我们应该能够在宽范围内调谐Eu（II）掺杂的混合双金属-氟化物的发射波长，因为氟化物显示蓝色或绿色的发射，而Eu（II）显示黄色或红色的发射。此外，最近发展的合成方法将被用于重新研究已知的金属氧化物的晶体结构，例如。G. SrMgH 4，我们现在可以制备单相，并尝试制备新的主晶格，如在系统KMgH 3-M（II）MgH 4与M（II）= Sr，Ba或Sr 1-yBayMgH 4。在制备和表征上述铕掺杂的金属氧化物时，我们希望阐明在这类新的主体晶格中控制Eu（II）发射的因素，并探索它们作为发光材料的潜力。