Lu2O3: Yb3+, Tm3+纳米晶的水热法合成和上转换发光性能研究

采用水热法制备了Yb3+和Tm3+共掺杂的Lu2O3纳米晶。研究了前驱体溶液pH对纳米晶的结构、形貌和上转换发光性能的影响。实验结果表明:制备出的纳米晶具有纯的Lu2O3相,结晶性较好。在980nm半导体激光器激发下,样品发射出蓝光和红光,其发光的中心波长分别位于490和653nm。当前驱体溶液pH为9时,Lu2O3:2%Yb3+,0.2%Tm3+纳米晶上转换发光强度最强,这是因为Lu2O3:2%Yb3+,0.2%Tm3+纳米晶的尺寸最大,其表面吸附的OH-基团最少。发射强度与激发功率的关系表明,蓝光490nm和红光653nm的发光是三光子过程。

Hydrothermal Synthesis and Upconversion Luminescent Properties of Lu2O3: Yb3+, Tm3+ Nanocrystals

Lutetium oxide nanocrystals codoped with Yb3+ and Tm3+ were synthesized by the hydrothermal method. Effect of the pH values of precursor solutions on the structure, morphology and upconversion luminescent properties of the nanocrystals was investigated. XRD results show that all the nanocrystals can be indexed to pure cubic phase of Lu2O3 with good crystallinity. Blue and red emissions from the prepared nanocrystals are observed at 980 nm laser excitation, which are located at 490 nm and 653 nm, respectively. The upconversion emission intensity of Lu2O3:2%Yb3+, 0.2%Tm3+ nanocrystals prepared at pH=9 is the strongest. The enhancement of the upconversion luminescence is suggested to be the consequence of the decreased number of OH- groups and the enlarged nanocrystals size. Power-dependent investigation reveals that the blue (490 nm) and red (653 nm) upconversion luminescence is a three-photon upconversion process