Liao Jinsheng, Wang Minghua, Lin Fulin, Han Zhuo, Fu Biao, Tu Datao, Chen Xueyuan, Qiu Bao, Wen He-Rui
School of Chemistry and Chemical Engineering/Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Jiangxi University of Science and Technology, Ganzhou, Jiangxi, 341000, P. R. China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Nat Commun. 2022 Apr 19;13(1):2090. doi: 10.1038/s41467-022-29784-6.
Rare earth (RE)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at high temperatures. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc(MoO):Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er are achieved upon raising the temperature from 298 to 773 K. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of I of Er in Sc(MoO):Yb/Er displays a strong temperature dependence, enabling luminescence thermometry with the highest relative sensitivity of 12.3%/K at 298 K and low temperature uncertainty of 0.11 K at 623 K. These findings may gain a vital insight into the design of negative-thermal-expansion RE-doped phosphors for versatile applications.
稀土（RE）掺杂的磷光体通常会受到热猝灭的影响，即在高温下其光致发光（PL）强度会降低。在此，我们报道了一类独特的二维负热膨胀磷光体Sc(MoO):Yb/Er。由于敏化剂与发射体之间的距离减小以及随着温度升高能量迁移受限，当温度从298 K升高到773 K时，Er的绿色上转换（UC）发光增强了45倍，近红外下转换（DS）发光增强了450倍。通过原位温度相关拉曼光谱、同步辐射X射线衍射和PL动力学系统地研究了热增强的UC和DS发光机制。此外，Sc(MoO):Yb/Er中Er的I发光寿命表现出强烈的温度依赖性，实现了发光测温，在298 K时具有12.3%/K的最高相对灵敏度，在623 K时具有0.11 K的低温不确定性。这些发现可能为设计用于多种应用的负热膨胀RE掺杂磷光体提供重要的见解。
