Li Mingchen, Yuan Maohui, Cui Wenda, Huang Hanchang, Guo Chuan, Han Kai
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, Hunan 410073, China.
Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, Hunan 410073, China.
ACS Omega. 2024 Sep 10;9(38):39893-39903. doi: 10.1021/acsomega.4c05453. eCollection 2024 Sep 24.
Inorganic host matrices provide a tunable luminescence environment for lanthanide ions, allowing for the modulation of upconversion luminescence (UCL) properties. AREF (A = alkali metal, RE = rare earth) have a low phonon energy and a high optical damage threshold, making them widely used as the host matrix for UCL materials. However, the impact mechanism of alkali metal ions and lanthanide lattice ions on transient UCL dynamics in AREF remains unclear. This study utilized a high-power nanosecond-pulsed laser at 976 nm to excite Yb-Er codoped NaLnF and LiLnF (Ln: Y, Lu, and Gd) microcrystals (MCs). All samples exhibit multiband emission, and the transient UC dynamics are discussed in detail. Compared with LiLnF, NaLnF has higher UC efficiency and red to green (R/G) ratio. Lanthanide ions (Y, Lu, and Gd) affect the energy transfer (ET) distance in Yb-Er codoped systems, thereby altering UC efficiency and the R/G ratio. The energy level coupling between Gd and Er prolongs the duration of the UC emission. Specifically, the red emission lifetime of NaGdF is five times longer than that of NaYF. Our research contributes to exploring excellent alternative host matrices for NaYF in the fields of rapid-response optoelectronic devices, micro-nano lasers, and stimulated emission depletion (STED) microscopy.
无机主体基质为镧系离子提供了一个可调节的发光环境，从而能够对上转换发光（UCL）特性进行调制。AREF（A = 碱金属，RE = 稀土）具有低声子能量和高光学损伤阈值，这使得它们被广泛用作UCL材料的主体基质。然而，碱金属离子和镧系晶格离子对AREF中瞬态UCL动力学的影响机制仍不清楚。本研究利用976 nm的高功率纳秒脉冲激光激发Yb - Er共掺杂的NaLnF和LiLnF（Ln：Y、Lu和Gd）微晶（MCs）。所有样品均表现出多波段发射，并对瞬态上转换动力学进行了详细讨论。与LiLnF相比，NaLnF具有更高的上转换效率和红/绿（R/G）比。镧系离子（Y、Lu和Gd）影响Yb - Er共掺杂体系中的能量转移（ET）距离，从而改变上转换效率和R/G比。Gd和Er之间 的能级耦合延长了上转换发射的持续时间。具体而言，NaGdF的红色发射寿命比NaYF的红色发射寿命长五倍。我们的研究有助于在快速响应光电器件、微纳激光器和受激发射损耗（STED）显微镜等领域探索优异的NaYF替代主体基质。
