钨酸钇基LED白色荧光粉的结构调控与性能优化

Single-phased white-emitting phosphors excited by long wavelength ultraviolet LED have obvious development potential in comparison with those excited by short wavelength ultraviolet LED and multi-phased phosphors. In this project, the possibility of realizing white emission in single-phased monoclinic Y2WO6 will be investigated, through obtaining the emissions both from Y2WO6 matrix and other activators by manipulating the crystal field and the luminescent centers with dopants. By using first-principles calculation, the composition, crystal and electronic structures will be designed, and the electronic structure of the excited sate will also be studied to acquire the theoretical luminescent properties, exploiting the relationship between structures and properties of monoclinic Y2WO6 . Based on the theoretical calculation, we hope to obtain phosphors with high performance by optimizing preparing methods. Relationship between luminescent and photocatalytic properties will be studied to intensively investigate the transfer process of the photo-generated electrons. The successful implement of this project will supply useful information from theoretical and experimental viewpoints on whether the Y2WO6 will be a good matrix for single- phased white-emitting phosphors excited by long wavelength ultraviolet LED chips. We have a solid research foundation and sufficient preliminary investigations, and possess interdisciplinary researchers, ensuring the smooth carrying out of this project.

单基质长波紫外光激发的白光LED荧光粉相对于多基质和短波紫外光激发的荧光粉具有明显的发展潜力。本项目以单斜晶系Y2WO6为基质，拟通过元素掺杂调节晶体场、激活剂，同时实现基质和激活剂的发光，探索同一基质内实现白色发光的可能性。以第一性原理计算设计材料的组分、晶体结构和电子结构，并进行激发态电子结构计算获得理论的发光性能，阐释单斜晶系Y2WO6的结构与性能的关系。以理论计算结果作为指导，通过优化制备工艺，获得具有优良综合性能的发光材料。进行光催化与发光性能的关系研究，以深入理解光生电子的转移过程。本研究的顺利实施，可以从理论和实验上给出钨酸钇基单一基质内实现长波紫外LED激发的白色发光的依据，为白光LED的发展做出重要贡献。本项目具有坚实的研究基础和充分的前期预研及明显的交叉学科性质，能保证研究方案的顺利实施。

单基质长波紫外光激发的白光 LED 荧光粉相对于多基质和短波紫外光激发的荧光粉具有明显的发展潜力。本项目以单斜晶系 Y2WO6 为基质，通过元素掺杂调节晶体场、点缺陷和激活剂，同时实现了长波紫外线激发的基质和激活剂的发光，在同一基质内实现了白色发光。第一性原理计算和实验相结合，系统研究了制备工艺、材料组分、晶体结构和电子结构的关系及对发光性能的影响，揭示了影响氧空位浓度的制备工艺因素以及氧空位的发光机制，然后通过元素掺杂调制了氧空位的局域能级和其发光过程，从而在钨酸钇内获得了长波紫外激发的自激活发光。将钨酸钇基质的发光与Sm等的发光结合，通过调节稀土元素的掺杂浓度，调制了发光颜色，实现了白色发光。调节了水热工艺参数，获得了球形的钨酸钇前驱体，优化了荧光粉的发光性能。进行了钨酸盐基质发光材料的激发态计算，预测了能在其内发光的掺杂元素。研究了钨酸盐的光催化性能，发现了光催化与发光性能的反向关系。将钨酸盐的研究结果作为基础，探索了其它自激活发光材料体系，通过热酸处理显著提高了C3N4的发光强度，实现了C3N4与Cu的配合物组成的复合材料的白色发光，发现了C3N4光动力抑制癌细胞的功能，预测了调制黑磷纳米带光学性能的边界钝化元素（集团），通过表面沉积SiO2钝化层提高了黑磷在空气中的稳定性。将点缺陷控制机理用于其他发光材料体系如ZnO和磷酸盐，实现了发光颜色的调节和发光性能的提高。本项目从理论和实验上给出自激活发光材料实现长波紫外激发的白色发光的依据，为LED用荧光粉的发展做出了重要贡献，并拓展了该类材料在生物医学和纳米电子领域的应用基础研究。点缺陷电子结构研究及其调制方法也为光转换材料研究提供了重要的参考。