植物生长灯用Mn4+激活复相结构荧光材料的制备和热稳定性研究

Light is an indispensable energy source for photosynthesis. Normal LED limited applied in the agricultural field due to lack of emission at high red light region. Prepared the high wavelength band, high thermal stability luminescent material can solve the above problem and make the LED have wide range of application in agriculture field. The obtained manganese ions doped double-phased luminescent material in previous work will be used as breakthrough point in this project. The main aims of this project is try to explore the way of prepare high wavelength band manganese ions doped double-phased luminescent material and analysis the interaction between luminescent properties host material types, single or double phased, to clear the mechanism of double-phased increase luminescence intensity. The obtained luminescent material will coat by the atomic layer deposition process. The coating rate, coating compactness and uniformity of the coating layer from difference coating methods will be study. How the thermal barrier influences the luminescent properties, crystal properties, microstructure and thermal stability of material will be observe very carefully as a model. Finally, the general rule of heat transfer through the nano-barrier layer will be reveals by the means of comparing the heat transfer properties of host material and barrier’s bulk material, which will afford a theoretical basis for developing new double phased agricultural lighting luminescent material. The work has great scientific significance for the development of high wavelength band luminescent materials and the development of three-dimensional powder surface modification technology.

光是植物光合作用不可缺少的能量来源，普通LED可为农业提供人工光，却因在高波段缺少发射被限制使用，制备高波段、高热稳定荧光材料能够解决以上问题，为LED在农业领域大范围应用提供可能。本项目以前期工作中得到的锰离子激发复相结构荧光材料为切入点，探索合成锰离子激发铝酸盐双基质高波段荧光材料，分析双、单基质荧光材料的发光性质及基质材料之间的相互作用，澄清复相结构增强发射的机制；通过单原子气相沉积技术包覆所得荧光材料，研究不同包覆方式对于荧光材料表面热障涂层的包覆速率、涂层的致密性、均匀性等的影响规律；考察热障涂层对荧光材料发光性能、晶体特性、微观形貌和热稳定性的影响方式，结合基质材料和热障涂层宏观材料本身的传热特性，揭示微观纳米涂层对传热方式影响的一般规律，为发展新型复相结构农业照明用荧光材料提供理论基础。该工作对拓展现有高波段荧光材料和发展粉体三维材料表面改性技术具有重要的科学意义。

光是植物光合作用不可缺少的能量来源，普通LED可为农业提供人工光，却因在高波段缺少发射被限制使用，制备高波段、高热稳定荧光材料能够解决以上问题。在研究复相材料Y3Al5O12/YAlO3:Mn4+的过程中遇到了困难，因此及时调整了研究方向。在复相研究基础上获得了一种新型高热稳定性（150℃，98.5%）复相材料Na3La(PO4)2/LaPO4:Eu。另外，申请者通过六种荧光粉改性优化策略，获得一批性能优越的荧光粉。（i）基于局域结构设计提高Mn4+激活深红光发射锌铝酸盐荧光粉的发光性能。以Sr4Al14O25:Mn4+为研究对象，通过局域Ba掺杂形成固溶体增强该荧光粉的发光强度和热稳定性。在Ca14Ga10Zn6O35:Mn4+中，采取局域共取代策略，发光强度分别提高为169.4%、195.0%和198.9%，内外量子效率分别为50.9%和38.9%。（ii）基于能量传递策略增强LED植物生长灯用荧光粉的发光性能。对Y3Al5O12，Sr8ZnY(PO4)7分别实现了Dy3+-Mn4+, Tb3+-Eu3+能量传递，优化了发光强度和量子效率，并对后者实现蓝-橙-红发射。（iii）基于电荷补偿策略增强LED植物生长灯用荧光粉的发光强度。申请人利用三种不同的金属阳离子Mg2+、Zn2+和Ca2+作为Mn4+的电荷补偿剂共同掺入到SrAl3BO7:Mn4+中。发光强度和内量子效率(IQE)分别提高到189%和32%、146% 和29%、115%和29%。（iv）基于固溶强化策略提高荧光粉发光性能。在La2MgTiO6:Mn4+中，通过Y取代La，热稳定性达到83.5%，发射光谱蓝移约11nm。在SrMgAl10-yGayO17：Mn4+荧光粉中，Ga取代Al发生了明显的红移，发光强度增强163%。（v）基于缺陷构筑策略提高荧光粉发光性能。在Ca14−xAl10Zn6−yO35:Mn4+荧光粉中，进行了Ca2+和Zn2+空位工程，在CaYAl1-xO4: xTi4+中设计Ca2+空位，均获得良好的热稳定性。（vi）基于过量离子掺杂策略提高荧光粉发光性能。申请人团队通过过量掺杂Al3+实现了一石二鸟，同时增强Ca14Al10Zn6O35:Mn4+荧光粉的量子效率和热稳定性。