单色近紫外激光泵浦旋转无机远程荧光体的红绿蓝光及核壳光散射作用机制

By using monochromic laser to pump rotating remote phosphor to achieve RGB color mix is a new low-cost colorful display technology, but some fundamentals still need to be recognized, such as the interaction between high power laser and the solid remote phosphor, and the realization of red light in RGB color mix. This project proposal is to try to use 405 nm monochromatic near-ultraviolet laser to pump the remote phosphor. The phosphor is a variety of glass ceramic phosphor consisting of luminous crystal particles embedded in the glass matrix, particularly with red emission from Mn ions. The trichromatic phosphors are based on magnesium silicate materials actived by Eu/Ce/Mn ions, particularly the red-light-emitting phosphors actived by Mn ions. The inorganic glass ceramic phosphor will be prepared by melting silica at low temperature with a strategy of subtly using Si-O bonding from both phases to obtain composite bulk with uniformly -distributed particles embedded in silica glass matrix. A single particle core-shell structure model will be established based on the Rayleigh-Debye scattering theory, to examine the interaction of incident light and extracted light on the interface between phosphor particle and glass matrix. A relationship is to be established to correlate the extraction efficiency with the size of phosphor particles, distribution, radius ratio of the core/shell and the effective refractive index, as well. The results will further the understanding of interaction mechanisms between the strong laser and solid phosphor and will obtain intellectual property rights, and will provide a reference to select the new phosphor materials to realize the monochromatic laser colorful display.

采用单色激光泵浦旋转远程荧光体来实现RGB是全新的低成本多彩显示技术，但是强激光与远程荧光体的相互作用机理目前尚不清楚，而RGB三色中要重点解决红光发射问题。本项目提出采用405纳米的单色近紫外激光，利用Mn离子的特征红光发射，在玻璃基质中镶嵌RGB荧光晶粒的全无机玻璃陶瓷复合远程荧光体实现RGB的新方案。采用Eu/Ce/Mn离子激活的硅酸镁基质成分，制备基于Mn离子红光的红绿蓝三原色荧光颗粒，再巧妙利用低温熔化时玻璃基质和荧光颗粒两相的Si-O键合，获得荧光颗粒均匀分布的玻璃荧光板；基于一个单颗粒核/壳结构界面模型，利用瑞利-德拜散射理论，考察入射光、发射光和玻璃基质与荧光晶体颗粒之间界面的相互作用，关联光的抽取效率与荧光颗粒大小、空间分布、核壳厚度比及折射率之间的关系。研究结果可以深化强激光与固体荧光材料相互作用机制的认识，为完善单色激光多彩技术的显示材料提供科学的解决方案。

项目重点探索Eu/Mn共掺杂的硅酸盐红色荧光粉，荧光板的制备，转光效率的提高，发掘此技术的其他应用。1.对于Eu/Mn共激活的A3MgSi2O8(A=Ba,Sr,Ca)发光粉，Eu2+取代A2+，Mn2+取代Mg2+位置，Eu2+/Mn2+形成配对，Eu2+在发射蓝光的同时，传递部分能量给Mn2+中心使其发射红光，Eu2+与Mn2+之间的能量传递为偶极－偶极相互作用，Eu2+与Mn2+之间的距离越小传递几率越大，和Eu2+处于激发态的寿命相比，能量传递所需要的时间越短能量传递越容易发生。当A=Ba时硅酸盐晶体结构对称性降低，Eu2+的4f65d1→4f7的能级跃迁增强并打破了Mn2+离子的3d-3d禁戒能级跃迁，量子效率提高。A= Sr+Ba时，Ba2+优先取代Sr(Ⅰ)格位， Eu2+占据Sr(Ⅱ、Ⅲ)格位，使Eu2+与周围的O原子配位数减少，键能变大，增加样品的热稳定性能。2.将硅酸盐荧光粉（蓝、绿、红、紫色荧光粉，分别为Sr3MgSi2O8: Eu2+、Ba2SiO4: Eu2+、Ca3Si2O7: Eu2+、Ba1.3Sr1.7MgSi2O8: Eu2+,Mn2+）@硅酸盐玻璃凝胶（CaO-SiO2）颗粒，经冷等静压成型(P=40MPa)，700℃加热使玻璃原料熔化，通过侵蚀熔解Si-O键合，形成相容性好的荧光粉玻璃界面，快冷后熔体形成非晶玻璃通过界面把荧光粉体颗粒连接起来，得到玻璃陶瓷复合荧光板。近紫外激光作用于固定在旋转框架中的荧光体，实现了单色激光的多彩转光发射。3.在激光与荧光板的作用过程中，因板体表面反射、板体透射、荧光颗粒的散射和吸收等过程，影响转光效率。其中基质板体的材料、均匀度、厚度、表面属性，荧光颗粒的形状、尺寸、分布，荧光颗粒与基质的界面属性，都是影响转光效率的因素，从理论上进行了分析，并使用光学模拟软件建立模型，设立属性，进行了光线追迹分析，分析结果对荧光板的制备提供依据，上述工作将继续展开。4.蓝色激光泵浦红色荧光板，应用激光的合束、光学整形、分色、合光及匀光、投射技术，将红蓝光按照一定的功率比例混合，投射到工作面上，满足植物生长所需的光合条件，这是激光转光的又一新的应用创新。