Tailoring bandgap and trap distribution via Si or Ge substitution for Sn to improve mechanoluminescence in Sr3Sn2O7:Sm3+ layered perovskite oxide
Tailoring bandgap and trap distribution via Si or Ge substitution for Sn to improve mechanoluminescence in Sr3Sn2O7:Sm3+ layered perovskite oxide
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DOI：
10.1016/j.actamat.2017.12.003
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发表时间：
2018-02-15
期刊：
影响因子：
9.4
通讯作者：
Kawasaki, E.
中科院分区：
文献类型：
--
作者：
Li, Jun;Xu, Chao-Nan;Kawasaki, E.
采用固相反应法合成了两个新化合物Sr-3(Sn2-xSix)O-7:Sm3+和Sr-3(Sn2-xGex)O-7:Sm3+，并研究了它们的结构、光学带隙、陷阱分布以及相关的磷光和机械发光（ML）性质。结果表明：通过引入Si或Ge，形成了具有层状钙硅酸盐结构的固溶体；典型成分Sr2.994Sm0.004(Sn1.9Si0.1)O-7和Sr2.994Sm0.004(Sn1.75Ge0.25)O-7的ML强度分别是Sr2.994Sm0.004 sn2o7的1.40 ~ 1.47倍和2.45 ~ 2.60倍，在压缩载荷阈值以上，ML曲线的线性度发生了较大变化。吸收光谱、磷光衰减曲线和热释光曲线表明，调整光带隙和陷阱分布可以改善ML的性能。带隙的适度减小增加了紫外预激发期间的电子捕获，而能带隙的扩大阻碍了电子的去捕获。增加陷阱密度会增加被困电子或空穴的数量。我们的研究结果表明，调整光学带隙和陷阱分布可能是开发高强度机械发光材料的新途径。(C) 2018材料学报Elsevier Ltd.出版。版权所有。
Two new compounds, Sr-3(Sn2-xSix)O-7:Sm3+ and Sr-3(Sn2-xGex)O-7:Sm3+, were synthesized by a solid-state reaction method and their structure, optical bandgap, trap distribution and related phosphorescence and mechanoluminescence (ML) properties were investigated. The results showed that a solid solution with a layered perovsldte structure was formed and the ML was increased by introducing Si or Ge. For typical compositions of Sr2.994Sm0.004(Sn1.9Si0.1)O-7 and Sr2.994Sm0.004(Sn1.75Ge0.25)O-7, the ML intensities were are about 1.40-1.47 and 2.45-2.60 times than that of Sr2.994Sm0.004Sn2O7, respectively, and the threshold of the compression load above which the linearity of the ML curves changed greatly. The absorption spectra, phosphorescence decay curves, and thermoluminescence showed that adjusting the optical bandgap and trap distribution may improve the ML properties. A moderate reduction of the bandgap increased the electron trapping during the UV pre-excitation, whereas broadening the energy gap hampered electron detrapping. Increasing the trap density increased the quantity of trapped electrons or holes. Our result implies that adjusting the optical bandgap and trap distribution may be a new route for developing high-intensity mechanoluminescent materials. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.