Sensitization of lanthanide-based phosphors by transition metals for high-brightness tunable thermometers (SensiTherm)

用于高亮度可调谐温度计的过渡金属对稀土基荧光粉的敏化（SensiTherm）

• 批准号: 426574030
• 负责人: Professor Dr.-Ing. Frank Beyrau, since 3/2022
• 金额: --
• 依托单位: Narodowe Centrum Nauki
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426574030?language=en
• 关键词: Sensitization; lanthanide; based; phosphors; transition

The main objective of this project is to enhance the photoluminescence properties of lanthanide-based optical thermometers via sensitization by transition metal ions. Taking advantage of the significantly higher absorption cross section of transition metal ions, the emission intensity of the lanthanide ions can be significantly enhanced, which will increase the signal levels offered by the thermometers. In addition, because the energy transfer from sensitizer to activator is strongly temperature-dependent, the sensitization of lanthanide emissions through transition metal ions will open a new path to enhance the temperature sensitivity of co-doped luminescent thermometers. To achieve this goal a detailed understanding of the sensitization process of lanthanides by transition metal ions in microcrystalline particles will be developed. The influence of material parameters such as local crystal field, phonon energy, dopant concentration, and energy level difference between excited states of activator and sensitizer on the temperature-dependent sensitization process enables the control and intentional design of luminescent thermometers with high emission intensity and high sensitivity to temperature changes. To investigate the energy transfer, microcrystalline samples will be synthesized in Wroclaw, and the spectroscopic properties will be investigated in Magdeburg using dispersed particle methods and quantum yield measurements to unambiguously quantify the absorption, energy transfer and emission processes. Host, sensitizer and activator dependent parameters will be investigated by systematically probing a range of combinations. The absorption cross section, the energy transfer rate, as well as radiative and non-radiative de-excitation rates will be measured, which will also serve as a comparison for theoretical models developed in Wroclaw. Those rates will also be measured over a range of dopant concentrations (sensitizer and activator), excitation power densities and temperatures to investigate the effect of each parameter on the sensitization process. The proposed project brings together the expertise of Wroclaw in the synthesis, structural characterisation and theory of transition metal and lanthanide doped compounds, with that of Magdeburg in advanced spectroscopic techniques based on probing the luminescence of dispersed particles in temperature-controlled fluid flow systems. Implementation of this project will provide an extensive characterization of energy transfer processes between transition metals and lanthanides, for both fundamental understanding as well as to provide luminescence thermometers with enhanced characteristics (more suitable excitation window, higher emission intensity, higher temperature sensitivity) which will greatly contribute to the progress of many fields of science for which temperature is a property of foremost importance.

本项目的主要目的是通过过渡金属离子敏化来增强镧系元素基光学温度计的光致发光特性。利用过渡金属离子显著更高的吸收截面，镧系元素离子的发射强度可以显著增强，这将增加温度计提供的信号水平。此外，由于敏化剂到激活剂的能量传递具有很强的温度依赖性，通过过渡金属离子对镧系元素发射的敏化将为增强共掺杂发光温度计的温度灵敏度开辟一条新的途径。为了实现这一目标，将详细了解微晶颗粒中过渡金属离子对镧系元素的增敏过程。材料参数的影响，如本地晶体场，声子能量，掺杂剂浓度，和激发态的激活剂和敏化剂的温度依赖性敏化过程之间的能级差，使控制和有意识的设计具有高发射强度和高灵敏度的发光温度计的温度变化。为了研究能量转移，将在弗罗茨瓦夫合成微晶样品，并在马格德堡使用分散粒子方法和量子产率测量来明确量化吸收、能量转移和发射过程，研究光谱特性。将通过系统探测一系列组合来研究主体、敏化剂和活化剂依赖性参数。吸收截面，能量转移率，以及辐射和非辐射去激发率将被测量，这也将作为在弗罗茨瓦夫开发的理论模型的比较。还将在掺杂剂浓度（敏化剂和活化剂）、激发功率密度和温度范围内测量这些速率，以研究每个参数对敏化过程的影响。拟议的项目汇集了弗罗茨瓦夫在过渡金属和镧系元素掺杂化合物的合成，结构表征和理论方面的专业知识，以及马格德堡在先进的光谱技术基础上探测温度控制流体流动系统中分散颗粒的发光。该项目的实施将为过渡金属和镧系元素之间的能量转移过程提供广泛的表征，以获得基本的理解，并提供具有增强特性（更合适的激发窗口，更高的发射强度，更高的温度灵敏度）的发光温度计，这将极大地促进温度是最重要属性的许多科学领域的进步。