摘要
采用两步高温热分解法合成了纳米异质结构的Na YF4∶Yb3+,Tm3+/Cd Se。X射线衍射测试结果表明样品由纯六角相的Na YF4(β-Na YF4)和纤锌矿型Cd Se组成。980 nm激发的上转换光谱表明Na YF4∶Yb3+,Tm3+和Cd Se之间存在能量传递,Tm3+将Yb3+传递给它的能量部分地传递给Cd Se,被激发的Cd Se又将能量回传给Tm3+的相应能级,最终使得Na YF4∶Yb3+,Tm3+的紫外和蓝光发射完全消失,而797 nm的近红外发射大幅增强。Na YF4∶Yb3+,Tm3+/Cd Se纳米异质结构的激发光和发射光均处于生物组织的光学透过窗口(700~1 100 nm),对生物组织的光损伤小,在生物医学领域有很大的应用潜力。
NaYF4∶Yb^3＋,Tm^3＋/CdSe nanoheterostructures with NIR-to-NIR upconversion luminescence were synthesized by a two-step improved wet-chemical method. X-ray diffraction（ XRD） characterization shows that the nanoheterostructures are composed of both pure hexagonal phase Na YF4∶ Yb3 ＋,Tm3 ＋and wurtzite phase Cd Se. Upconversion emission spectra under the excitation of 980 nm near-infrared laser show that 797 nm emission from Tm3 ＋ions has been enhanced greatly,while neither ultraviolet nor blue emissions of Tm3 ＋appear compared with that of pure Na YF4∶ Yb3 ＋,Tm3 ＋. It indicates that the energy transfer occurs between Na YF4∶ Yb3 ＋,Tm3 ＋and Cd Se. Under 980 nm excitation,the energy absorbed by Yb3 ＋ions transfers to Tm3 ＋ions,then transfers to Cd Se partially,and finally the excited Cd Se returns the energy back to the corresponding energy levels of Tm3 ＋. These processes lead to the quenching of UV and blue emissions and the enhancement of 797 nm emission of Tm3 ＋ions in the NaYF4∶Yb^3＋,Tm^3＋/CdSe nanoheterostructures. The excitation（ 980 nm） and emission（ 797 nm） are both located in the NIR spectral range（ 700- 1 100 nm） that is referred as the ＂optical window＂of biological tissues because of the minimum of light scattering and autofluorescence of tissue and a relatively large penetration depth. Therefore,the present NaYF4∶Yb^3＋,Tm^3＋/CdSe nanoheterostructures could have potential applications in biology and biomedicine fields.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2015年第5期491-496,共6页
Chinese Journal of Luminescence
基金
国家自然科学基金(11274139
11474132)资助项目
作者简介
何光辉（1989-），男，四川达州人，硕士研究生，2013年于吉林大学获得学士学位，主要从事上转换纳米材料和半导体量子点的制备及应用的研究。E—mail：954041796@qq．com
狄卫华（1977-），男，江苏南通人，副教授，2006年于中科院长春光学精密机械与物理研究所获得博士学位，主要从事稀土基功能纳米材料的可控合成、发光物理及其在光电器件、生物传感、生物示踪标记等方面的研究。E—mail：whdi@jlu．edu．cn
秦伟平（1961-），男，吉林长春人，教授，博士生导师，1999年于中科院长春物理研究所获得博士学位，主要从事稀土上转换发光性质及其器件的研究。E—mail：wpqin@ilu．edu．cn
