“铽桥”敏化的高显色新型红色荧光粉的设计、高通量制备及其发光性能研究

Phosphor-converted semiconductor-based white LED is a new type of green lighting. The products of white LED have been widely used in general lighting, but the high value-added products for whtie LED are top lighting and display backlights with wide color gamut. The red phosphors presently used in white LED are mainly activated with ions with broad-band emission, which can not meet the requirements. The aim of this project is to develop several high colour rendering new red phosphors being applicable to be excited by near-UV or violet-emitting LED chips, which are activated with Eu3+ ions in polyphosphate hosts and enhanced the emission by the bridge chains of energy transfer, Ce3+-(Tb3+)n-Eu3+, where Ce3+ is a sensitizer with adjustable excitation bands and Tb3+ ions are mrdia for energy transfer. To overcome the complexity problem of the research objects, combinatorial method is used to prepare phosphors with high throughput and synchrotron radiation is employed to analyze the phase. The key research contents are to adjust the excitation and emission spectra by host and codoping, to study the relationships among the composition of phosphors, the structure of material and the change of energy levels, to explore the mechanism of energy transfer of terbium bridges and its influence factors, and to improve the emission efficiency and the thermal quenching resistant property of the phosphors by codoping with additional non-emitting rare-earth ions and energy transfer. Moreover, we will fabricate LED devices with as-prepared phosphors and chips, and study their properties. The present research has many important values in the fields of inorganic solid state chemistry, chemistry and physics of rare-earths, and solid state luminescence, which will lay a good foundation for acquiring the research findings with independent intellectual property.

荧光转换型半导体基白光LED被誉为绿色光源，已广泛用于普通照明，但附加值更高的高端照明与显示背光源要求产品具有广色域。目前所用红粉多为宽带发射，不能满足其要求。本项目拟以激发带可调的Ce3+为敏化剂、以Tb3+为传能媒介、以多磷酸盐为主要基质、构建形如Ce3+-(Tb3+)n-Eu3+的“铽桥”来敏化Eu3+的红光发射，从而获得适于近紫外-紫光芯片激发的新型高显色红色荧光粉，采用“组合化学”方法高通量合成以解决体系复杂性问题，利用同步辐射对其进行物相解析。通过基质及共掺离子来调控Ce3+的激发和发射光谱，围绕材料组成、物质结构和能级变化间的关系开展研究，探明“铽桥”传能机制及其影响因素，利用共掺无辐射稀土离子、能量传递等方法提高荧光粉的发光效率与热猝灭性能；研制相应器件，研究其性能。本研究在无机固体化学、稀土化学与物理、固体发光学等方面具有重要学术价值，可为取得知识产权奠定良好基础。

荧光转换型半导体基白光LED被誉为绿色光源，已广泛用于普通照明，但附加值更高的高端照明与显示背光源要求产品具有广色域。目前所用红粉多为宽带发射，不能满足其要求。本项目主要以激发带可调的Ce3+为敏化剂、以Tb3+为传能媒介，构建了形如Ce3+-(Tb3+)n-Eu3+的“铽桥”来敏化Eu3+的红光发射，从而获得了多种适于近紫外-紫光芯片激发的新型高显色窄带红色荧光粉，详细研究了材料组成、物质结构和能级变化间的关系，研制了相应的LED器件并研究了其电致发光性能。取得的主要研究成果有：（1）设计并合成了荧光材料共计19种，其中可用于近紫外-紫光LED芯片激发的红色荧光材料9种、可用于近紫外-紫光LED芯片激发的白光荧光材料7种、可用于近紫外-紫光LED芯片激发的蓝色及绿色荧光材料3种。（2）共发表学术论文16篇；申请中国发明专利14项，其中3项专利获得授权。（3）培养博士后研究人员4名、博士生3名、硕士生4名。本项目总体上超额完成了计划任务。本研究取得的研究成果在无机固体化学、稀土化学与物理、固体发光学等方面具有重要的学术价值，获得的知识产权可为成果的应用提供保障。