适于3D 显示的短余辉绿光发射真空紫外发光材料探索

Three-dimensional (3D) flat panel display technologies are rapidly developing nowadays. Plasma display panel (PDP), which has many technical advantages such as high contrast, high refresh rate, a large viewing angle, high color reproduction, is the best way to achieve 3D display. Phosphors are key materials for PDP. The decay time of green-emitting phosphor, which restricts the development of 3D-PDP, is a key issue to be solved. In this project, we propose a new idea to realize fast-decay green-emitting by taking into account the crystal structure of host compounds, the coordination polyhedra around luminescent centers, the ligands, the bond length, the coordination number, and the site symmetry. This idea is using Eu2+ as an activator and Ce3+ as a sensitizer. We will prepare the phosphors and investigate their luminescence in vacuum ultraviolet–visible (VUV-vis) spectral range, get the insight into the energies of the high 5d excited states of Eu2+ and Ce3+ at different sub-lattice sites, understand the factors those have influence on the energies of these states and energy-transfer between them. Based on this work, we devote to finding fast-decay green-emitting VUV phosphors for 3D display. In addition, this project will promote the developments of synchrotron radiation VUV experimental station, so that more users can perform their research on chemistry, material science, and condensed matter physics by the station.

3D平板显示技术的迅速发展,大大超出人们的预期.PDP是实现3D的最佳方式.在对比度、刷新率、可视角度、色彩还原能力等方面,3D-PDP有3D-LCD无可匹敌的优势.发光材料是实现PDP显示功能、影响PDP显示质量的核心材料.绿光发射材料的余辉时间,是制约3D-PDP发展、迫切需要解决的瓶颈问题.在综合考虑发光材料基质化合物晶体结构、发光中心配位形式、配位原子及键长、配位数、格位特点等因素基础上,本课题提出利用Eu2+离子作为激活离子,Ce3+离子作为敏化离子的新思路,合成并研究发光材料的VUV-vis光谱,理解不同微环境对Eu2+、Ce3+离子5d激发态高能级及基质-Ce3+/Eu2+离子间能量传递的影响,探索适于3D显示的短余辉绿光发射VUV发光材料.课题的实施,还可推动同步辐射VUV实验线站建设,带动更多用户利用同步辐射VUV光源进行化学、材料科学、固体物理等领域交叉前沿问题研究.

为探索适于3D 显示的短余辉绿光发射真空紫外发光材料，本项目采用高温固相反应方法，合成了Eu2+/Ce3+离子掺杂的硼酸盐、铝酸盐、硅酸盐、磷酸盐等复合氧化物基质发光材料。利用北京同步辐射装置(BSRF)的真空紫外(VUV)光谱实验站，测定了材料在VUV-UV-vis范围的发光性质。研究了材料的荧光衰减性质及温度、掺杂浓度对发光和荧光衰减、能量传递的影响及X-射线激发下的发光光谱和低压阴极射线激发下的发光光谱。发现在VUV光及低压阴极射线激发下，Sr8(Si4O12)Cl8:Eu2+有色坐标为(0.136, 0.298)的绿蓝色(青色)快衰减(~0.9 μs)强发射，表明该材料在宽色域3D显示方面的潜在应用。此外，在X-射线激发下，Sr8(Si4O12)Cl8:Eu2+有高的光产额，表明作为闪烁材料在射线探测方面的潜在应用。通过Ce3+离子在不同基质中的VUV-UV-vis范围的光谱，分析了电子云扩大效应(共价性、光谱极化率)和电-声作用对Ce3+离子5d能级重心的影响；讨论了Ce3+离子配位数和键长、配位多面体形式等因素对晶体场强度及Ce3+离子5d轨道分裂能的影响；结合光谱测定结果，利用从头计算系统研究Ce3+离子在一些基质中的5d轨道能量；研究了Sr5(PO4)3Cl:Ce3+,Eu2+中Ce3+→Eu2+的能量传递过程。资助项目执行期间，培养出站博士后1名，已获学位博士研究生6名，已获学位硕士研究生5名。截至目前，已在包括美国化学会(ACS)出版的Chem. Mater.、J. Phys. Chem. C，英国化学会(RSC)出版的J. Mater. Chem. C、Dalton Trans.、Phys. Chem. Chem. Phys.，美国光学学会(OSA)出版的Opt. Lett.和Opt. Express，美国物理联合会(AIP)出版的J. Appl. Phys.等期刊发表标注基金资助的研究论文30 篇。参加国际国内学术会议报告8次。申请国家发明专利4件。获得广东省科学技术二等奖1项。