Wang Xiao, Liu Mei-Hong, Xu Qing, Zhang De-Long, Zhang Pei, Wong Wing-Han
Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, and Key Laboratory of Optoelectronic Information Science & Technology (Ministry of Education), Tianjin University, Tianjin 300072, China.
Department of Opto-electronics and Information Engineering, School of Precision Instruments and Opto-electronics Engineering, and Key Laboratory of Optoelectronic Information Science & Technology (Ministry of Education), Tianjin University, Tianjin 300072, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 15;249:119335. doi: 10.1016/j.saa.2020.119335. Epub 2020 Dec 15.
Er-doped NaLa(WO) is a promising phosphor material for applications in many fields including the ratiometric thermometry based on thermal effect of fluorescence intensity ratio (FIR) of green fluorescence of Er, which is directly correlated with Judd-Ofelt parameters Ω (i = 2, 4, 6). Present paper reports synthesis and Judd-Ofelt spectroscopic properties of Er-doped NaLa(WO) µm-sized phosphor. The phosphor was synthesized by solid-state chemical reaction and characterized by X-ray diffraction and Raman scattering techniques. The results show that the phosphor is dominated by NaLa(WO) crystalline phase and has a maximum phonon energy 927 cm. Judd-Ofelt analysis was done for the phosphor using a safe, reliable method based on diffuse reflection spectrum and Er 1.5 μm fluorescence lifetime. First, diffuse reflection spectrum of the phosphor was measured and relative absorption spectrum was calibrated from it using Kubelka-Munk theory. Second, Er 1.5 μm fluorescence lifetime of the phosphor was measured and absorption cross-section spectrum was obtained based on the assumption that the 1.5 μm emission has 100% quantum efficiency. Finally, based on the absorption cross-section spectrum, standard Judd-Ofelt analysis was carried out to extract the Ω. Radiative rate, fluorescent branch ratio and radiative lifetime of some transitions have been obtained from the known Ω values. In addition, FIR proportional factor was evaluated in terms of Ω and compared with those values of other materials. The result shows that the phosphor has a better prospect for the application in ratiometric thermometry.
掺铒的NaLa(WO)是一种很有前景的荧光粉材料，可应用于许多领域，包括基于铒绿色荧光的荧光强度比（FIR）热效应的比率测温法，该热效应与Judd-Ofelt参数Ω（i = 2, 4, 6）直接相关。本文报道了掺铒的NaLa(WO)微米级荧光粉的合成及Judd-Ofelt光谱性质。该荧光粉通过固相化学反应合成，并采用X射线衍射和拉曼散射技术进行表征。结果表明，该荧光粉以NaLa(WO)晶相为主，最大声子能量为927 cm。使用基于漫反射光谱和铒1.5μm荧光寿命的安全可靠方法对该荧光粉进行Judd-Ofelt分析。首先，测量荧光粉的漫反射光谱，并根据Kubelka-Munk理论从中校准相对吸收光谱。其次，测量荧光粉的铒1.5μm荧光寿命，并基于1.5μm发射具有100%量子效率的假设获得吸收截面光谱。最后，基于吸收截面光谱进行标准的Judd-Ofelt分析以提取Ω。从已知的Ω值获得了一些跃迁的辐射速率、荧光分支比和辐射寿命。此外，根据Ω评估了FIR比例因子，并与其他材料的值进行了比较。结果表明，该荧光粉在比率测温法中的应用具有较好的前景。
