Phosphor Nanostructures: Synthesis and Applications

荧光粉纳米结构：合成与应用

• 批准号: RGPIN-2021-03515
• 负责人: Kitai, Adrian
• 金额: $ 2.4万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=752916
• 关键词: Phosphor; Nanostructures; Synthesis; Applications

Objectives: The over-arching objective of this proposal is the study and development of yttrium aluminum garnet (YAG)--based oxide phosphor nanopowders as fluorescent materials that are much more stable than either organic or quantum dot alternatives. Goals include gaining a fundamental understanding of fluorescent phosphor nanoparticles with a long term view to primary application areas including fluorescent solar concentrators and microLEDs. Significance: A Fluorescent Solar Concentrator (FSC) can enable future photovoltaic (PV) building windows for the Building Integrated PhotoVoltaic (BIPV) industry. Here a building window collects sunlight and waveguides it to the edges of the window where it is converted into electricity by silicon solar cells. The nanosize aspect allows visible light scattering to be minimized. A 25 year lifespan is dictated by BIPV component standards. This may be satisfied by very stable oxide fluorescent materials, the best known materials being versatile YAG hosts containing rare earth or transition metal activators. Organic dyes and quantum dots are unable to meet these lifespan requirements. The MicroLED offers the promise of a new display revolution in which well--developed inorganic solid state p-n junction light emitters are dramatically scaled down to produce red/green/blue (RGB) display pixels small enough for cellphone displays. The required size of a single colour sub-pixel is ?10µm to enable 60µm RGB pixels in a retina screen cellphone display. Benefits of the microLED include wide colour gamut, mechanical flexibility for fold-up/roll-up displays and a 6--fold power consumption decrease compared to current LCD and OLED screens. Optimized white--emitting nano-phosphors are required for these microLEDs. Approach: We will focus on fundamental but industrially relevant aspects of fluorescent nanoparticles. Investigation of energy transfer between emission centers will be carried out via optical spectroscopy, in which the concentrations and associated emission intensities of the sensitizing atom (Ce) and activators (Mn, Nb) are controlled in both core--only and core--shell YAG nanophosphors. We aim to extend the surface oxidation technique we have recently investigated to create Mn2+-or Mn4+ charge--compensated activators.   Yttrium, aluminum, and cerium all occupy 3+ valence states in the YAG host. When Mn occupies an Al site, there may be a local charge imbalance. The charge imbalance provides a non--radiative pathway for relaxation acting as a luminescence quenching site which should be avoided. The YAG host is well suited as an infrared emitter with rare earth dopant Nd where it is used to absorb near-infrared radiation in the 800nm range with fluorescence at 1100nm. In order to absorb visible light, energy transfer between Ce and Nd will be utilized.

目标：本提案的总体目标是研究和开发钇铝石榴石（YAG）为基础的氧化物荧光粉纳米粉作为荧光材料，比有机或量子点替代品更稳定。目标包括获得对荧光荧光粉纳米粒子的基本理解，并长期着眼于主要应用领域，包括荧光太阳能聚光器和微型led。意义：荧光太阳能聚光器（FSC）可以为建筑集成光伏（BIPV）产业实现未来的光伏（PV）建筑窗户。在这里，一个建筑物的窗户收集阳光，并将其波导引导到窗户的边缘，在那里它被硅太阳能电池转化为电能。纳米尺寸方面允许可见光散射最小化。BIPV组件标准规定了25年的使用寿命。这可以通过非常稳定的氧化物荧光材料来满足，最著名的材料是含有稀土或过渡金属活化剂的多功能YAG宿主。有机染料和量子点无法满足这些寿命要求。MicroLED提供了一种新的显示革命的希望，在这种革命中，发展良好的无机固态p-n结光源被大幅缩小，以产生足够小的红/绿/蓝（RGB）显示像素，用于手机显示。单色子像素的所需尺寸为？10µm使60µm RGB像素在视网膜屏幕手机显示。与目前的LCD和OLED屏幕相比，microLED的优点包括宽色域，折叠/卷式显示的机械灵活性和6- 1的功耗降低。这些微型led需要优化的白色发光纳米荧光粉。方法：我们将重点关注荧光纳米粒子的基本但工业相关的方面。发射中心之间的能量转移研究将通过光谱学进行，其中敏化原子（Ce）和激活剂（Mn, Nb）的浓度和相关发射强度在核心-纯和核心-壳YAG纳米荧光粉中被控制。我们的目标是扩展我们最近研究的表面氧化技术，以创建Mn2+或Mn4+电荷补偿活化剂。钇、铝和铈在YAG基体中均为3+价态。当Mn占据Al位点时，可能存在局部电荷不平衡。电荷不平衡为弛豫提供了一个应避免的非辐射途径。YAG宿主体非常适合作为稀土掺杂Nd的红外发射器，用于吸收800nm范围内的近红外辐射，荧光在1100nm。为了吸收可见光，将利用Ce和Nd之间的能量转移。