基于微分相调控晶化与选择性富集增强发光的LED照明用多相白光玻璃陶瓷研究

The strategy of “UV-LED + Multi-phase White Luminescent Glass-ceramics” is considered as one of the most prospective method to realize general illumination via high power WLEDs simultaneously with high external quantum efficiency (EQE) and high color rendering index (CRI), but it still remain several challenges need to be urgently overcome. The first is how to design and prepare multi-crystalline-phase glass-ceramics in Crystal Chemistry. The second is how to suppress luminescence quenching among different activators in Luminescence Dynamics. The third is how to fit different activators with suitable Ligand Field to obtain targeted excitation/emission band. To well solve these critical issues, we propose to develop one type of multi-phase white luminescent fluoro-boro-alumino-silicate glass-ceramics with homogeneously dispersing Eu2+ doped SrF2 nano-crystallites, molecule-like [(Ag)m]n+ doped B2O3-rich micro-phase separation, and [(Ag)x]y+ doped ZnO-Al2O3-rich micro-phase separation. 1) The molecular dynamic simulation method of “phase separation simulation – predicting crystallization – composition designation” and the preparation method of “melting – pre-separated micro-phase – induced crystallization” will be jointly utilized to develop the multi-phase glass-ceramics containing SrF2 nano-crystallites, B2O3-rich micro-phases and ZnO-Al2O3-rich micro-phases. 2) In order to suppress luminescence quenching among different activators, the parity-permitted transition possessed activators, such as self-stabilized Eu2+, molecule-like [(Ag)m]n+ and [(Ag)x]y+, will doped to selectively enrich into SrF2 nano-crystallites, B2O3-rich micro-phases and ZnO-Al2O3-rich micro-phases. This will help the glass-ceramics to be luminescently functionalized with large UV absorption and intense visible emission. 3) The energy levels and luminescence spectra will be theoretically simulated to comparatively study and adjust the local coordination environments of Eu2+, [(Ag)m]n+ and [(Ag)x]y+ to fit their excitations into the same UV region and separation their emissions into different blue/green/red region. It is favored by the generation of white light emitting with warm correlative color temperature (CCT) and high CRI. The deployment of this proposal will provide new critical luminescent materials and theoretical methodology for developing high power WLED devices with high EQE, warm CCT, high CRI and good thermostability, showing great scientific research significance and bright engineering application prospect.

“紫外LED+多相白光玻璃陶瓷”被认为是大功率LED照明同时实现高光效和高显色指数的最重要研究方向之一，但亟需解决设计制备多相玻璃陶瓷的结晶化学难题、抑制发光中心间发光猝灭的发光动力学难题、及协调多发光中心高效产生白光的配位场调控难题。为此，本项目拟在氟铝硼硅酸盐玻璃体系中:1)基于微分相调控析晶思路，采用“模拟分相-预测析晶-设计组成”的分子动力学方法和“熔制-微分相-晶化”的制备方法，研制一类含SrF2晶相、富B2O3微分相、富ZnO-Al2O3微分相的多相玻璃陶瓷;2)利用具有允许跃迁的Eu2+、[(Ag)m]n+、[(Ag)x]y+分别选择性富集重掺于玻璃陶瓷的SrF2晶相、富B2O3微分相、富ZnO-Al2O3微分相，克服发光中心间发光猝灭，提高光效;3)结合激发态与光谱计算，优化Eu2+、[(Ag)m]n+、[(Ag)x]y+局域配位环境，使其具有相同紫外激发和不同蓝绿红发射波段，协作产生高显色指数白光。

LED照明技术是进入21世纪以来各国大力发展的新型节能照明技术。“紫外LED+多相白光玻璃陶瓷”被认为是大功率LED照明同时实现高光效和高显色指数的最重要研究方向之一，但亟需解决设计制备多相玻璃陶瓷的结晶化学难题、抑制发光中心间发光猝灭的发光动力学难题、及协调多发光中心高效产生白光的配位场调控难题。为此，本项目设计、制备和研究了一类氟锌铝硼硅酸盐玻璃，主要获得了以下重要结果和关键数据：.(1).基于微分相调控析晶的思路，采用“模拟分相-预测析晶-设计组成”的分子动力学设计方法和“熔制成型-微分相-晶化”的制备方法，设计并研制了一类均匀含有SrF2晶相、富B2O3微分相和ZnAl2O4晶相的Ag/Eu2+共掺 SiO2-Al2O3-B2O3-Na2O-SrO/SrF2-ZnO/ZnF2多相玻璃陶瓷；.(2).利用具有允许跃迁的二价Eu2+、类分子态Agmn+、离子对(Ag+)2等高效发光中心分别选择性富集并均匀重掺于多相玻璃陶瓷的SrF2晶相、富B2O3微分相、ZnAl2O4晶相，克服发光中心间的发光猝灭问题，实现材料的强吸收和高效发光功能化。其中，单相玻璃陶瓷的蓝、绿、红发光内量子效率分别可达78.14 %、55.7%和26.8%。.(3).结合激发态与光谱计算，优化Eu2+、Agmn+、(Ag+)2局域化学配位状态使其具有一致的紫外激发波段和分别具有蓝、绿、红三基色发射波段，协作产生暖色温、高显色指数白光。多相玻璃和玻璃陶瓷的白光内量子效率分别可达67.38 %和39.17 %。.(4).试制了3W的单芯片和50W的多芯片LED灯，获得了一类暖白光、高显色指数的大功率固态照明器件，其色坐标为(0.32,0.36)、色温为5900K左右、显色指数可达89。.因此，本项目成果为研发一类大功率、暖色温、高显色指数的新型LED照明器件提供了新的材料基础和理论方法，具有重要的科学意义和工程应用价值。