P-3(0) -> D-1(2) non-radiative relaxation control via IVCT state in Pr3 -doped Na(2)Ln(2)Ti(3)O(10) (Ln = La, Gd) micro-crystals with triple-layered perovskite structure
P-3(0) -> D-1(2) non-radiative relaxation control via IVCT state in Pr3 -doped Na(2)Ln(2)Ti(3)O(10) (Ln = La, Gd) micro-crystals with triple-layered perovskite structure
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P-3(0) -> D-1(2) 通过 IVCT 状态在 Pr3 掺杂 Na(2)Ln(2)Ti(3)O(10) (Ln = La, Gd) 微中进行非辐射弛豫控制
DOI：
10.1016/j.jlumin.2019.04.048
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发表时间：
2019
影响因子：
3.6
通讯作者：
Suchocki Andrzej
中科院分区：
文献类型：
--
作者：
Wang Yongjie;Peng Qi;Liang Hongbin;Brik Mikhail G.;Suchocki Andrzej
对 Pr3+ 掺杂层状钙钛矿 Na2Ln2Ti3O10(Ln=La, Gd) 微晶稀土位点不同取代位点的发光性质及其性质进行了比较研究。在室温下，Ln=La 的样品在带隙激发下表现出强烈的绿蓝色（3P0→3H4）和红色（1D2→3H4）发射，而对于 Ln=Gd，只能观察到红色发射，并且所有 3P0 相关的发射都被完全淬灭。事实证明，Na2Ln2Ti3O10(Ln=La，Gd)中的3P0→1D2非辐射弛豫关键取决于Pr3+-Ti4+间质电荷转移态的能量位置，从而取决于Pr3+基态3H4相对于价带顶部的位置。 4.5–300K 范围内的温度依赖性光致发光光谱显示 Pr3+ 发光显着增加，这归因于从主体到 Pr3+ 离子的有效热激活能量转移过程。 Ln=Gd 的自俘获激子态相对于导带底部的较低能量是导致在比 Ln=La 样品更高的温度下观察到的热致发光的原因。对于Ruddlesden-Popper型层状钙钛矿氧化物化合物，我们的结果表明可以控制Pr3+离子的3P0→1D2非辐射弛豫以及相对于导带底部的相对较浅的陷阱的能量距离，为这些材料中的特定带隙工程提供了一种方法。
A comparative study on luminescence properties and their nature in relation to different substitutions at the rare-earth site of Pr3+-doped layered perovskite Na2Ln2Ti3O10(Ln = La, Gd) micro-crystals has been reported. At room temperature, the sample for Ln = La exhibits intense greenish-blue (3P0→3H4) and red (1D2→3H4) emissions under bandgap excitation, whereas for Ln = Gd the red emission can be only observed and all3P0-related emissions were completely quenched. It turns out that3P0→1D2nonradiative relaxation in Na2Ln2Ti3O10(Ln = La, Gd) critically depends on the energy location of Pr3+-Ti4+intervalence charge transfer state and thus on the location of Pr3+ground state3H4with respect to the top of the valence band. Temperature-dependent photoluminescence spectra in the 4.5–300 K range reveals a significant increase of Pr3+luminescence, which is ascribed to an efficient thermally-activated energy transfer process from host to Pr3+ions. Lower energy of self-trapped exciton state relative to the bottom of conduction band for Ln = Gd is responsible for thermoluminescence observed at higher temperatures than that for Ln = La sample. In the case of Ruddlesden-Popper type layered perovskite oxide compounds our results show a possibility of controlling the3P0→1D2nonradiative relaxation of Pr3+ions and the energy distance of the relatively shallow traps in relation to the bottom of conduction band, giving a way for specific band-gap engineering in these materials.