强上转换发光的LiLu1-xYbxF4∶Tm@LiGdF4核壳纳米晶的制备

利用高温热分解法制备了LiLuF4∶Yb,Tm@LiGdF4核壳纳米晶。在980 nm激光激发下, 与未包覆的样品相比, LiLuF4∶Yb,Tm@LiGdF4核壳纳米晶的发光增强了15倍左右, 这主要是因为通过惰性壳层的包覆可以有效抑制表面猝灭效应。另外, 随着核中Yb3+离子的摩尔分数从20%增加到100%, 上转换发光强度逐渐增大, 最大增加了12.4倍左右。这主要是由于增加Yb3+离子的浓度可以增加纳米粒子对激发光的吸收和提高Yb3+到Tm3+的能量传递速率。所制备的LiYbF4∶2%Tm@LiGdF4核壳纳米晶的发光效率高达4%。

Abstract

LiLuF4∶Yb,Tm@LiGdF4 core-shell nanoparticles were synthesized by high temperature thermal decomposition method. Under the excitation of980 nm near infrared (NIR) laser, the luminescence intensity of the core-shell nanoparticles can be enhanced by about 15 times in contrast to the pure LiLuF4 core. It is due to the passivating role of the inert-shell for protecting Tm3+ ions in the core from nonradiative decay caused by surface defects. The intensity of the UC emission of the nanocrystals increases (at most 12.4 times) as the mole fraction of Yb3+ ions increases from 20% to 100%, owing to the improvement of near-infrared absorption and energy-transfer from Yb3+ to Tm3+. LiYbF4∶2%Tm@LiGdF4 core-shell nanoparticles show a high absolute UC quantum yield of 4.0%.

参考文献

[1] WANG F, BANERJEE D, LIU Y S, et al.. Upconversion nanoparticles in biological labeling, imaging, and therapy ［J］. Analyst, 2010, 135(8):1839-1854.

[2] LIU J N, BU W B, PAN L M, et al.. Simultaneous nuclear imaging and intranuclear drug delivery by nuclear-targeted multifunctional upconversion nanoprobes ［J］. Biomaterials, 2012, 33(29):7282-7290.

[3] HEER S, KMPE K, GDEL H U, et al.. Highly efficient multicolour upconversion emission in transparent colloids of lanthanide-doped NaYF4 nanocrystals ［J］. Adv. Mater., 2004, 16(23-24):2102-2105.

[4] PANG M, ZHAI X S, FENG J, et al.. One-step synthesis of water-soluble hexagonal NaScF4∶Yb/Er nanocrystals with intense red emission ［J］. Dalton Trans., 2014, 43(26):10202-10207.

[5] WEISSLEDER R. A clearer vision for in vivo imaging ［J］. Nat. Biotechnol., 2001, 19(4):316-317.

[6] MAHALINGAM V, VETRONE F, NACCACHE R, et al.. Colloidal Tm3+/Yb3+-doped LiYF4 nanocrystals: multiple luminescence spanning the UV to NIR regions via low-energy excitation ［J］. Adv. Mater., 2009, 21(40):4025-4029.

[7] HUANG P, ZHENG W, ZHOU S Y, et al.. Lanthanide-doped LiLuF4 upconversion nanoprobes for the detection of disease biomarkers ［J］. Angew. Chem. Int. Ed., 2014, 53(5):1252-1257.

[8] WANG M, CHEN Z, ZHENG W, et al.. Lanthanide-doped upconversion nanoparticles electrostatically coupled with photosensitizers for near-infrared-triggered photodynamic therapy ［J］. Nanoscale, 2014, 6(14):8274-8282.

[9] CHEN Q, SUI J H, CAI W. Enhanced upconversion emission in Yb3+ and Er3+ codoped NaGdF4 nanocrystals by introducing Li+ ions ［J］. Nanoscale, 2012, 4(3):779-784.

[10] LIU N, QIN W P, QIN G S, et al.. Highly plasmon-enhanced upconversion emissions from Au@β-NaYF4∶Yb, Tm hybrid nanostructures ［J］. Chem. Commun., 2011, 47(27):7671-7673.

[11] VETRONE F, NACCACHE R, MAHALINGAM V, et al.. The active-core/active-shell approach: a strategy to enhance the upconversion luminescence in lanthanide-doped nanoparticles ［J］. Adv. Funct. Mater., 2009, 19(18):2924-2929.

[12] ZHAI X S, LIU S S, ZHANG Y L, et al.. Controlled synthesis of ultrasmall hexagonal NaTm0.02Lu0.98-xYbxF4 nanocrystals with enhanced upconversion luminescence ［J］. J. Mater. Chem. C, 2014, 2(11):2037-2044.

[13] QIU H L, CHEN G Y, FAN R W, et al.. Intense ultraviolet upconversion emission from water-dispersed colloidal YF3∶Yb3+/Tm3+ rhombic nanodisks ［J］. Nanoscale, 2014, 6(2):753-757.

[14] SUN Y, ZHU X J, PENG J J, et al.. Core-shell lanthanide upconversion nanophosphors as four-modal probes for tumor angiogenesis imaging ［J］. ACS Nano, 2014, 7(12):11290-11300.

[15] ZHAI X S, LIU S S, LIU X Y, et al.. Sub-10 nm BaYF5∶Yb3+, Er3+ core-shell nanoparticles with intense 1.53 μm fluorescence for polymer-based waveguide amplifiers ［J］. J. Mater. Chem. C, 2013, 1(7):1525-1530.

[16] 张鹏, 李大光, 刘世虎, 等. Gd3+, Tm3+和Yb3+掺杂的Y2O3微晶中Gd3+离子的紫外上转换发光及其增强的研究［J］. 发光学报, 2015, 36(8):893-897.

ZHANG P, LI D G, LIU S H, et al.. UV upconversion luminescence of Gd3+ in Yb/Tm/Gd doped Y2O3 microcrystals ［J］. Chin. J. Lumin., 2015, 36(8):893-897. (in Chinese)

[17] LIU H C, XU C T, LINDGRE D, et al.. Balancing power density based quantum yield characterization of upconverting nanoparticles for arbitrary excitation intensities ［J］. Nanoscale, 2013, 5(11):4770-4775.

[18] LOUIE A. Multimodality imaging probes: design and challenges ［J］. Chem. Rev., 2010, 110(5):3146-3195.

翟雪松, 刘世虎, 范柳燕, 刘杰, 焦宝祥, 王丽丽. 强上转换发光的LiLu_1-xYb_xF₄∶Tm@LiGdF₄核壳纳米晶的制备[J]. 发光学报, 2017, 38(9): 1149. ZHAI Xue-song, LIU Shi-hu, FAN Liu-yan, LIU Jie, JIAO Bao-xiang, WANG Li-li. Preparation of LiLu_1-xYb_xF₄∶Tm@LiGdF₄ Core-shell Nanocrystals with Enhanced Upconversion Luminescence[J]. Chinese Journal of Luminescence, 2017, 38(9): 1149.

强上转换发光的LiLu_1-xYb_xF₄∶Tm@LiGdF₄核壳纳米晶的制备

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