特殊晶场环境下二价锰离子的非常规获得及反常发光的机理研究

Luminescent materials have important application in lighting and displays. Mn2+, an important activator, shows various luminescent characteristics in different crystal field environments. Being synthesized under reducing atmosphere, it will meet the problem of being oxidized and the chromaticity coordinate deviation after a long time working at high temperature. Recently, novel Mn2+ activated luminescent materials were synthesized under ambient atmosphere in our group. They can not only simplify the preparation technology, but also avoid oxidation at high temperature. Especially, these materials are free from thermal quenching until 200 centigrade. Therefore, it is very important in scientific research and application to clarify the unconventional stabilization and the abnormal luminescence mechanism of Mn2+ in special crystal field environments. The project focus on the research of new Mn2+ activated luminescent materials synthesized under ambient atmosphere. The interaction between the host matrix and the activators is taken as the main line. The characteristically crystal field environment of Mn2+ stabilization in ambient atmosphere will be verified, and the mechanism of the abnormal luminescence will be revealed by crystal structure determination, the analysis of the occupancy of the doping ions, combined with the first-principles calculation, and various spectrum measurements. Novel luminescent materials will be obtained in the project, and the knowledge of the luminescence of Mn2+ will be deepened, the theory of the luminescence of Mn2+ will be enriched as well. The results will guide the development of new Mn2+ activated luminescent materials more effectively.

发光材料在发光和显示领域有重要的应用。Mn2+作为一种重要的激活离子，在不同晶场环境下的发光具有多样化特点，但需还原性气氛制备。长时间高温工作后Mn2+易被氧化并导致色度坐标偏移。本项目组近期在空气中获得了Mn2+激活的发光材料，不仅简化了制备工艺，而且可避免高温氧化，甚至到200度发光无热猝灭。因此，弄清特殊晶场环境下Mn2+离子非常规获得规律及其反常发光机理，具有重要的科学与实际意义。本项目拟以空气中制备的Mn2+激活发光材料为研究对象，以基质与Mn2+离子间的相互作用为主线，从结构入手，通过研究基质晶体结构与Mn2+的晶格占位，结合第一性原理计算和光谱分析，探明在空气中稳定Mn2+所需的晶场环境及规律，揭示Mn2+在特殊晶场环境下出现反常发光的机理。不但可获得新发光材料，更可加深对Mn2+离子发光规律的认识，丰富Mn2+离子发光理论。研究结果将有效指导Mn2+激活发光新材料的研发。

二价锰离子是一种重要的发光材料激活离子，在不同晶场环境下的发光具有多样化特点，其发光可随晶场环境改变而从绿光变化到红光，传统需要还原性气氛进行制备。长时间高温工作后Mn2+易被氧化并导致色度坐标偏移。为弄清特殊晶场环境下Mn2+离子非常规获得规律及其反常发光机理，本项目以空气中制备的Mn2+激活发光材料为研究对象，以基质与Mn2+离子间的相互作用为主线，从结构入手，通过研究基质晶体结构与Mn2+的晶格占位，结合第一性原理计算和多种光谱手段分析，探明在空气中稳定Mn2+所需的晶场环境及规律，揭示Mn2+在特殊晶场环境下出现反常发光的机理。.在项目执行期间，系统研究了多个碱金属锌/镁基硼/磷/铝/硅/锗酸盐体系中，空气中高温烧结Mn4+掺杂发光材料后演变为Mn2+的物理过程。开发出大量无需还原气氛，可在空气中高温下稳定的二价锰离子激活发光材料，多数具有优异的高温热稳定性，有些甚至到200度发光无热猝灭。不仅简化了制备工艺，而且避免了二价锰离子长期高温下工作被氧化而导致的色度坐标偏移，为大功率暖白光LED照明提了供理想选择。提出了缺陷辅助锰离子自发还原的物理机制，揭示了Mn2+在特殊晶场环境下出现反常发光的机理，加深了对Mn2+离子发光规律的认识，丰富了Mn2+离子发光理论，研究结果有效指导了Mn2+激活发光新材料的研发。.同时，在研究过程中发现，部分样品在具备光致发光性质的基础上，同时表现出弹性应力发光特性，可用于实时压力传感、应力分布可视化、光学防伪等多个领域。深化了对硼、磷、铝、硅、锗酸盐体系发光材料晶体结构和发光性质之间关系的认识，明确了晶格缺陷在发光材料研究中的重要作用，为后续光致、力致发光及长余辉发光材料的研发提供了新思路和新体系。