Liu Jianxia, Yang Chunwei, Qu Song, Xiao Ran, Lv Xiang, Chen Shunyi, Guo Ning
Department of Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, PR China.
Department of Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Jan 15;305:123560. doi: 10.1016/j.saa.2023.123560. Epub 2023 Oct 18.
The temperature-driven redshift of the charge transfer band (CTB) exhibits promising potential for optical temperature sensing as well as for the design of anti-thermal quenching phosphors. Therefore, it is essential to investigate the displacement mechanism in detail. In this contribution, we created LiCaMVO:5%Sm (M = Mg/Zn) phosphors with considerably red-shifted CTB edges upon temperature stimulation and outstanding anti-thermal quenching behavior. To investigate this unusual behavior, gaussian fitting was performed on the excitation spectra and emission spectra at different temperatures to investigate the redshift mechanism. By averaging the peak energy of the lowest excitation and emission peaks, the zero phonon line (E) indicating the electronic energy level location of the charge transfer state (CTS) shows a downward trend is obtained. As well as the energy reduction of the A(T)-B(T) and E(T)-B(T) absorption bands in the [VO] group is observed. Therefore, the drop in the CTS electronic energy level is the dominant factor in the temperature-driven CTB redshift. Based on the redshift phenomenon and anti-thermal quenching phenomenon of CTB, the phosphor exhibited exceptional optical temperature measurement performance in all three thermometry modes of excitation intensity ratio (EIR), International Committee on Illumination (CIE) color coordinates, and fluorescence intensity ratio (FIR), demonstrating its broad application prospects in the field of optical temperature sensing as well as guiding the design of anti-thermal quenching phosphors.
电荷转移带（CTB）的温度驱动红移在光学温度传感以及抗热猝灭磷光体设计方面展现出了广阔的应用潜力。因此，详细研究其位移机制至关重要。在本研究中，我们制备了LiCaMVO:5%Sm（M = Mg/Zn）磷光体，其在温度刺激下具有显著红移的CTB边缘以及出色的抗热猝灭性能。为了探究这种异常行为，我们对不同温度下的激发光谱和发射光谱进行了高斯拟合，以研究红移机制。通过对最低激发峰和发射峰的峰值能量进行平均，得到了指示电荷转移态（CTS）电子能级位置的零声子线（E）呈下降趋势。同时，还观察到[VO]基团中A(T)-B(T)和E(T)-B(T)吸收带的能量降低。因此，CTS电子能级的下降是温度驱动CTB红移的主导因素。基于CTB的红移现象和抗热猝灭现象，该磷光体在激发强度比（EIR）、国际照明委员会（CIE）色坐标和荧光强度比（FIR）这三种测温模式下均表现出优异的光学温度测量性能，展示了其在光学温度传感领域的广阔应用前景，并为抗热猝灭磷光体的设计提供了指导。
