Tunable dual-mode photoluminescence from nanocrystalline Eu-doped Li2ZnSiO4 glass ceramic phosphors
Tunable dual-mode photoluminescence from nanocrystalline Eu-doped Li2ZnSiO4 glass ceramic phosphors
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DOI：
10.1039/c0jm03273e
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Wondraczek, Lothar
中科院分区：
文献类型：
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作者：
Gao, Guojun;Reibstein, Sindy;Wondraczek, Lothar
我们报告了混合价 Eu 掺杂纳米晶 Li2ZnSiO4 玻璃陶瓷的可调谐光致发光。在空气中制备前体玻璃后，在热退火和晶体 Li2ZnSiO4 沉淀过程中，Eu3+ 逐渐还原为 Eu2+。可以产生双模光电发射以在约360 nm的波长下激发。所产生的发光颜色（从橙色/红色到蓝色）可以通过调节退火温度来控制，从而控制结晶程度：随着退火温度的升高，与Eu3+和Eu2+物种相关的发光强度的比率分别随着Eu3+还原程度的增加以及所获得的玻璃陶瓷的光学散射行为的明显变化而变化。同时，Eu2+相关光电子发射的带宽从87 nm增加到154 nm。基于动态发射光谱和结构考虑，讨论了光电子发射和从 Eu2+ 到 Eu3+ 的能量转移的基本机制，并给出了内部还原过程的描述。
We report on tunable photoluminescence from mixed-valence Eu-doped nanocrystalline Li2ZnSiO4 glass ceramics. After preparation of the precursor glass in air, gradual reduction of Eu3+ to Eu2+ occurs intrinsically during thermal annealing and precipitation of crystalline Li2ZnSiO4. Dual-mode photoemission can be generated for exciting at a wavelength of about 360 nm. The resulting colour of luminescence, ranging from orange/red to blue, can be controlled by adjusting the annealing temperature and, hence, the degree of crystallization: with increasing annealing temperature, the ratio of luminescence intensities related to Eu3+ and Eu2+ species, respectively, varies as a result of increasing degree of Eu3+-reduction as well as distinct changes in the optical scattering behaviour of the obtained glass ceramic. At the same time, the bandwidth of Eu2+-related photoemission increases from 87 to 154 nm. The underlying mechanisms of photoemission and energy transfer from Eu2+ to Eu3+ are discussed on the basis of dynamic emission spectroscopy and structural considerations, and a description of the internal reduction process is given.