New red phosphor with a high color purity: controlled synthesis of 3D architectures of YW2O6(OH)3 : Eu
New red phosphor with a high color purity: controlled synthesis of 3D architectures of YW2O6(OH)3 : Eu
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DOI：
10.1039/b820335k
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发表时间：
2009-07
期刊：
影响因子：
3.1
通讯作者：
Lin Xu;Chunliang Lu;Jianmin Shen;Yuping Chen;Zihui Zhang;W. Hou
中科院分区：
文献类型：
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作者：
Lin Xu;Chunliang Lu;Jianmin Shen;Yuping Chen;Zihui Zhang;W. Hou
首次采用无模板剂和无表面活性剂的水热法合成了具有微杨梅状和微花状三维超结构的单斜晶系YW 2 O 6（OH）3：Eu。通过改变前驱体介质的pH值，可以容易地实现形态调制。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、高分辨率TEM（HRTEM）、能量色散X射线（EDX）光谱和光致发光（PL）光谱对所得产物进行表征。在时间相关实验的基础上，提出了YW_2O_6（OH）_3：Eu分级结构的可能形成机制。对比实验表明，只有在合适的pH值范围（2 ~ 3）内，才能得到纯净、结晶良好的YW_2O_6（OH）_3：Eu。对杨梅状和花状两种结构的YW_2O_6（OH）_3：Eu样品的光致发光性能进行了研究，发现其光学性能与样品的结晶度和形貌密切相关。两种样品都表现出具有高色纯度的红色发射。更重要的是，微型杨梅比微型花表现出更强的发光，具有更高的R/O值，这意味着色纯度的提高。通过微调初始溶液的pH值，不仅可以获得更好的结晶度，而且可以实现提高红色纯度。并对这种改善的可能原因进行了讨论。
Monoclinic YW2O6(OH)3 : Eu with 3D hierarchical superstructures, namely, micro-waxberry and micro-flower, have been selectively synthesized via an efficient surfactant- and template-free hydrothermal process for the first time. Morphology modulation can be easily realized simply by changing the pH value of the precursor medium. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy-dispersive X-ray (EDX) spectrometry and photoluminescence (PL) spectra were employed to characterize the as-obtained products. A possible formation mechanism of the YW2O6(OH)3 : Eu hierarchical architectures was proposed on the basis of time-dependent experiments. Comparative experiments indicated that pure and well-crystallized YW2O6(OH)3 : Eu could be obtained only in an appropriate pH range of 2–3. An investigation on the PL properties of two YW2O6(OH)3 : Eu samples with waxberry-like and flower-like microstructures revealed that the optical properties were strongly correlated with the crystallinity and morphology. Both samples exhibited red emissions with a high color purity. More importantly, micro-waxberry displayed a stronger emission and possessed a much higher R/O value than micro-flower, implying an improvement of color purity. Through fine adjustment of the pH value of the initial solution from 3 to 2, not only was better crystallinity obtained, but also the enhanced red color purity could be realized. The possible reasons responsible for this improvement were discussed.