Collaborative Research: Multi-Photon Phosphors Based on Vacuum Ultraviolet Excitation

合作研究：基于真空紫外激发的多光子荧光粉

• 批准号: 0305400
• 负责人: Richard Meltzer
• 金额: --
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2007-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0305400&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; Photon; Phosphors

This program of experimental research is directed to the development of multiphoton phosphors. These materials convert an initial VUV high-energy photon into two visible photons of lower energy, thereby establishing a quantum of efficiency that can be greater than one. The approach defined here is to use energy-transfer processes among lanthanide ions to implement the multiphoton process. One lanthanide ion absorbs the VUV photon. This is followed by a cross-relaxation energy-transfer process in which the initially excited ion shares a portion of its energy with a different ion. Both ions are left with enough energy to each emit a visible photon of light, thereby efficiently utilizing the VUV photon from the lamp discharge to produce two visible photons. Three schemes will be examined for the energy transfer that involve both the 4fn and the 4fn-15d configurations of the lanthanide ions. From literature data on the energy levels of the lanthanides and their dependence on host material, a number of ion pairs and appropriate hosts have been selected for study that will maximize the chance for success. Since these schemes involve the use of highly excited states of solids located near the edge of the conduction band where mixing of localized and delocalized states can occur and where photoionization and charge-transfer processes can complicate the problem, it will be necessary to address some of the fundamental issues concerning the nature and dynamics of these highly excited states from the physics and materials perspectives. The project will be conducted by collaboration among three groups. The physics group at the University of Georgia will perform the optical characterization of the phosphors and study the dynamical properties of their highly excited states. The chemistry group at Oregon State University will produce the required phosphors and optimize their properties, and they will also develop new compositions that are likely to have the desired properties. Scientists at Osram Sylvania will contribute to the project with their time providing both experimental and theoretical support on the development and evaluation of phosphors, especially regarding their practical usefulness in real lamp devices.The U.S. utilizes almost 25% of its electricity-energy budget to satisfy the lighting requirements of our society. Current fluorescent lamps have a wall-plug efficiency of about 30% and their discard results in the dumping of large amounts of mercury into the environment. The proposed research will provide much needed insight into the processes and materials that are necessary to make the leap to a new multiphoton-phosphor technology and a new form of high-efficiency lighting that will lead to a substantial reduction of energy consumption and the elimination of mercury in lighting. The project will involve collaboration among three groups; physicists at the University of Georgia, chemists at Oregon State University, and industrial scientists at Osram Sylvania. Students will develop an in-depth understanding of multiphoton processes and materials design, providing a base for future contributions in the lighting industry or academe.

该实验研究计划针对多光子磷剂的发展。 这些材料将初始的VUV高能光子转换为两个可见的较低能量的光子，从而建立了一个可能大于一个的效率。 这里定义的方法是使用灯笼离子之间的能量转移过程来实施多光子过程。 一种灯笼离子吸收VUV光子。 接下来是交叉解释的能量转移过程，其中最初激发的离子与不同离子共享其一部分能量。 两个离子都有足够的能量来发射一个可见光的光子，从而有效利用灯泡放电的VUV光子产生两个可见光子。 将检查三个方案的能量转移，涉及灯笼离子的4FN和4FN-15D构型。 从有关灯笼的能量水平及其对宿主材料的依赖性的文献数据中，已经选择了许多离子对和适当的宿主进行研究，这将最大程度地提高成功的机会。 由于这些方案涉及使用位于传统带边缘附近的固体的高度激发态，在该固体中可能会发生局部和离域状态的混合，以及在光电离心和电荷转移过程中可能使问题复杂化的地方，因此有必要解决一些基本问题，从而使这些高度激发的状态和动力学从物理学和材料观察者角度观察到。 该项目将通过三个小组之间的协作进行。 佐治亚大学的物理小组将执行磷光体的光学表征，并研究其高度激发态的动力学特性。 俄勒冈州立大学的化学组将产生所需的磷光剂并优化其特性，它们还将开发出可能具有所需特性的新组合物。 Osram Sylvania的科学家将为该项目做出贡献，他们的时间为磷剂的开发和评估提供了实验性和理论支持，尤其是关于它们在真实灯具设备中的实际实用性。 当前的荧光灯的壁插入效率约为30％，其丢弃的结果导致大量汞倾倒到环境中。 拟议的研究将提供急需的洞察力，以实现发展新的多光磷酸技术和新形式的高效照明形式所需的过程和材料，这将大大减少能源消耗和消除照明中的汞。 该项目将涉及三个小组之间的合作；佐治亚大学的物理学家，俄勒冈州立大学的化学家和欧斯拉姆·西尔瓦尼亚的工业科学家。 学生将对多光过程和材料设计有深入的了解，为照明行业或学术界的未来贡献提供基础。