Wang Lili, Qin Weiping, Lan Min, Sun Lanlan, Liu Zhenyu, Zhao Dan, Qin Guanshi, Wu Changfeng, Chuai Xiaohong, Di Weihua, He Chunfeng
J Nanosci Nanotechnol. 2014 May;14(5):3490-3. doi: 10.1166/jnn.2014.7967.
Under 980 nm excitation, enhanced ultraviolet (UV) upconversion (UC) emissions at 242.4 nm, 276.1 nm, 289.7 nm, 296.4 nm, 303.6 nm, 357.7 nm and 387.8 nm of Ho3+ ions were observed in beta-NaYF4:20%Yb3+, 1.5%Ho3+ microcrystals (MC) which were synthesized through a hydrothermal method. The results indicated that these UV emissions came from five- and four-photon UC processes. Dynamical analysis on Ho3+ excited states suggests that, for excited Ho3+ ions, the higher the energy level is, the shorter the lifetime is.
在980 nm激发下，通过水热法合成的β-NaYF4:20%Yb3+、1.5%Ho3+微晶（MC）中观察到Ho3+离子在242.4 nm、276.1 nm、289.7 nm、296.4 nm、303.6 nm、357.7 nm和387.8 nm处增强的紫外（UV）上转换（UC）发射。结果表明，这些紫外发射来自五光子和四光子UC过程。对Ho3+激发态的动力学分析表明，对于激发的Ho3+离子，能级越高，寿命越短。
