论文标题
ndal $ _3 $（bo $ _3 $）$ _ 4 $纳米颗粒激发在1064 nm处的光子雪崩上转换
Photon avalanche up-conversion in NdAl$_3$(BO$_3$)$_4$ nanoparticles excited at 1064 nm
论文作者
论文摘要
我们在1064 nm的三价neododim（nd $^{3+} $）上报告有效的非共振状态激发，该激发在stoichiometric neodymim botore botore ndal $ _3 $（bo $ $ _3 $）中光致发光特性。观察到上转换（UCS）和确定的能量路径，因为从多声辅助基础状态吸收开始（$^4 $ i $ _ {9/2} $ - $^4 $ f $ f $ f $ _ {3/2} $）和激动的状态吸收（$^4 $ i $ i $ i $ _ $ _ $ _ $ _ $ _ $ _ $ _ $ _ $ _ $ _ $^4; $^4 $ i $ _ {11/2} $通过热耦合与接地状态。激发的状态$^4 $ i $ _ {11/2} $也由ND $^{3+} $ ions的放松填充，增加了$^4 $ f $ _ {3/2} $ LEVEL的总体。两个nd $^{3+} $ ions（$^4 $ f $ _ {3/2} $，$^4 $ i $ _ {9/2} $） - （$^4 $ i $ _ {15/2} $，$ i $ _ {15/2} $，$^4 $^4 $ i $ _ {15/2} $） $^4 $ i $ _ {11/2} $级别的每个迭代触发光子雪崩机制，从而大大提高了UCS的效率。梯子热激发$^4 $ f $ _ {3/2} $ - [$^4 $ f $ _ {5/2} $，$^2 $ h $ _ {9/2} $] - [$^4 $ f $ _ {7/2} $这些水平的状态放松分别提供了880 nm，810 nm，750 nm和690 nm的发射。 $^4 $ f $ _ {3/2} $等级的nd $^{3+} $离子之间的能源转移UCS（钻孔）允许[$^2 $ g $ _ {3/2} $，$^4 $ g $ g $ g $ _ {7/2} $的人口从哪个放松到$^4 $ i $ i $ i $ i $ _2} $^4 $ i $ _ {11/2} $和$^4 $ i $ _ {13/2} $状态分别提供了536 nm，600 nm和660 nm的排放。与非生育性弛豫相关，我们观察到纳米颗粒（22°C至240°C）的加热，随后由于ND $^{3+} $离子的耦合能水平的种群重新分布而导致频率UC的热量增强。
We report efficient non-resonant ground state excitation at 1064 nm of trivalent neodymium (Nd$^{3+}$) ions in stoichiometric neodymium aluminum borate NdAl$_3$(BO$_3$)$_4$ nanoparticles, which are crystalline and, besides the large content of Nd$^{3+}$ ions, present excellent photoluminescence properties. Up-conversions (UCs) were observed and the energy pathways identified, as starting by multi-phonon assisted ground state absorption ($^4$I$_{9/2}$-$^4$F$_{3/2}$) and excited state absorption ($^4$I$_{11/2}$-$^4$F$_{3/2}$) with the population of the $^4$I$_{11/2}$ level by thermal coupling with the ground state. The excited state $^4$I$_{11/2}$ is also populated by relaxations of the Nd$^{3+}$ ions increasing the population of the $^4$F$_{3/2}$ level. Cross-relaxation among two Nd$^{3+}$ ions ($^4$F$_{3/2}$,$^4$I$_{9/2}$)-($^4$I$_{15/2}$,$^4$I$_{15/2}$) with subsequent phonon emission leads to two ions at the $^4$I$_{11/2}$ level every iteration triggering a photon avalanche mechanism which greatly enhances the efficiency of the UCs. Ladder thermal excitation $^4$F$_{3/2}$-[$^4$F$_{5/2}$,$^2$H$_{9/2}$]-[$^4$F$_{7/2}$,$^4$S$_{3/2}$]-$^4$F$_{9/2}$ was achieved, and the ground state relaxation from these levels provided emission at 880 nm, 810 nm, 750 nm, and 690 nm, respectively. Energy transfer UCs (Auger) between Nd$^{3+}$ ions at the $^4$F$_{3/2}$ level allowed the population of the [$^2$G$_{3/2}$,$^4$G$_{7/2}$] from which relaxations to the $^4$I$_{9/2}$, $^4$I$_{11/2}$, and $^4$I$_{13/2}$ states provided emissions around 536 nm, 600 nm, and 660 nm, respectively. Associated with the nonradiative relaxations, we observed the heating of the nanoparticles (22 °C to 240 °C) with subsequent thermal enhancement of the frequency UCs due to the redistribution of population among coupled energy levels of the Nd$^{3+}$ ions.
