Understanding the emission redshift in Sr2Si5N8:Eu2+ with increasing Eu doping concentration from density functional calculations
Understanding the emission redshift in Sr2Si5N8:Eu2+ with increasing Eu doping concentration from density functional calculations
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通过密度泛函计算了解 Sr2Si5N8:Eu2 中随 Eu 掺杂浓度增加的发射红移
DOI：
10.1016/j.jlumin.2017.01.020
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发表时间：
2017-05
影响因子：
3.6
通讯作者：
Ning Lixin
中科院分区：
文献类型：
--
作者：
Huang Xiaoxiao;Sun Jiancheng;Sheng Xiaowei;Huang Yucheng;Ning Lixin
随着Eu浓度的增加，红色荧光粉Sr2Si5N8:Eu2+呈现出明显的发射红移，但原因仍有争议。本文利用密度泛函理论（DFT）方法和周期超级单体模型研究了Sr2Si5N8:Eu2+的能量、力学和电子特性。对Sr2−xEuxSi5N8（x=0.028, 0.125, 0.5）超级电池的总能量计算表明，Eu2+离子占据Sr1和Sr2两个不同的位置，具有几乎相同的优先性，Eu2+在两个Sr位置上的分布几乎均匀，与掺杂浓度无关。Debye温度和电子性质计算表明，随着eusr1或eusr2含量的增加，结构刚度逐渐降低，激发Eu2+(4f65d1)离子中占据的5d态变得更加离域，这可能导致5d→4f发射的Stokes位移增大，从而导致实验观察到的红移。
The red phosphor Sr2Si5N8:Eu2+exhibits a significant emission redshift with increasing Eu concentration, but the reason remains controversial. Here, we investigate energetic, mechanical, and electronic properties of Sr2Si5N8:Eu2+by using density-functional theory (DFT) approaches with the periodic supercell model. Total-energy calculations for Sr2−xEuxSi5N8(x=0.028, 0.125, 0.5) supercells reveal that Eu2+ions occupy the two distinct Sr1 and Sr2 sites with almost equal preference, with a nearly even distribution of Eu2+on the two Sr sites, irrespective of the doping concentration. Calculations for the Debye temperature and electronic properties show that, with increasing EuSr1or EuSr2content, the structural rigidity decreases gradually and the occupied 5d state in the excited Eu2+(4f65d1) ion becomes more delocalized, which may result in an enlarged Stokes shift of the 5d→4f emission and thus its redshift as observed experimentally.
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影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
DOI：
10.1201/b10939
发表时间：
2011-06
期刊：
--
影响因子：
--
作者：
Hajime Yamamoto
通讯作者：
Hajime Yamamoto
影响因子：
44.1
作者：
Freysoldt, Christoph;Grabowski, Blazej;Van de Walle, Chris G.
通讯作者：
Van de Walle, Chris G.
影响因子：
3.7
作者：
Brgoch, Jakoah;DenBaars, Steven P.;Seshadri, Ram
通讯作者：
Seshadri, Ram
影响因子：
3.7
作者：
Le Page, Y;Saxe, P
通讯作者：
Saxe, P