Ba3BPO7中的缺陷发光机理与光谱调控研究

This project is planned to carry out relevant research work based on the unusual spectroscopic properties of Ba3BPO7, which can be synthesized in a solid state reaction under reduction atmosphere and show the visible light emission under ultraviolet excitation. The origin and mechanism of the visible light emission in Ba3BPO7 will be investigated and elucidated by various characterization methods such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS) and fluorescence spectroscopy (FS) measurements as well as Density Functional Theory (DFT). The location and intensity of excitation and emission bands of Ba3BPO7 material can be controlled by regulating the defect energy levels and electronic structure of Ba3BPO7 material. A novel type of non-activated ion doped borophosphate luminescent materials with visible light emission under ultraviolet excitation can be obtained in this project. Then, the synergistic luminescence effect and energy transfer process between the defects and activated ions in Ba3BPO7 will be investigated by doping the metal ions with optical activity into the Ba3BPO7 matrix, and the luminescence properties with wide color gamut in Ba3BPO7 based materials can be achieved. This project can not only enrich the content about the defect chemistry and spectroscopy of borophosphate based luminescence materials, but also provide new ideas and methods for the design of novel luminescence materials, and has a certain theoretical and practical significance.

本项目拟围绕在固相反应中还原气氛下合成的Ba3BPO7在紫外光激发下具有可见光发射这种不寻常的光谱性质开展相关的研究工作。利用X射线粉末衍射, X射线光电子能谱, 红外光谱，拉曼光谱，荧光光谱等表征手段并结合密度泛函理论(DFT)研究并阐明Ba3BPO7中可见光发射的来源与机理。通过调控Ba3BPO7材料的缺陷能级与电子结构实现其激发/发射光谱带的位置与强度的可调性，有望制备出一类新型在紫外光激发下具有可见光发射的无激活离子掺杂的硼磷酸盐荧光材料。通过掺杂具有光学活性的金属离子如稀土离子，非稀土离子等，研究还原气氛下基质中产生的缺陷与掺杂的激活离子之间的协同发光效应与能量传递过程，实现Ba3BPO7基荧光材料的宽色域发射特性。本项目的开展不仅丰富了硼磷酸盐基荧光材料的缺陷化学与光谱学的内容，而且为设计新型荧光材料提供了新的思路与方法，具有一定的理论意义与现实意义。

无机发光材料是一类重要的无机功能材料，在照明和显示等领域都具有广泛的应用前景。设计新型的无机发光材料以及对其发光机理的研究近年来一直是发光材料领域一个重要的研究方向。本项目通过高温固相法设计合成了一类具有黄绿光发射的自激活型硼磷酸盐发光材料Ba3BPO7。研究表明该材料的黄绿光发射来自于在合成过程中引入的缺陷-氧空位。这种氧空位将会随着二次煅烧而逐渐减少。揭示了还原气氛CO对于氧空位产生的作用机理，提出了一种制备自激活型发光材料的方法。并通过将Tm3+, Sm3+两种稀土离子引入到该材料中，得到了两种具有可见光发射的荧光材料Ba3BPO7:Tm3+, Ba3BPO7:Sm3+，它们分别具有蓝光，橙红光发射。并对两种离子的浓度猝灭机制进行了深入地讨论。结果表明所合成的材料在白光LED领域具有潜在的应用前景。此外，为了探索缺陷发光这类特殊的发光特性在其他无机盐基质中的可能性，制备了基于钨酸盐NaMgLaWO6，磷酸盐Ba3P4O13，硼酸盐KBaY(BO3)2等发光材料，并研究了一些稀土离子在这些基质中的光谱性质与能量传递行为。发展了一系列能够与商用近紫外/蓝光LED芯片匹配的荧光材料。本项目的实施不仅为设计新型自激活型发光材料提供了新的思路，而且也在发展新型白光LED用荧光材料的道路上进行了必要的探索。