Er^(3+):NaYF_4纳米晶玻璃陶瓷的频率上转换动力学分析

Analysis of the Dynamics of Upconversion in Er^(3+):NaYF_4 Nanocrystal Glass-ceramic

通过测量Er3+:NaYF4纳米晶玻璃陶瓷的吸收光谱和上转换荧光光谱,结合Judd-Ofelt理论,计算Er3+各个能级间的辐射跃迁几率和无辐射跃迁几率.建立并求解Er3+的上转换速率方程,采用拟合归一化的荧光衰变实验曲线的方法,得到Er3+:NaYF4纳米晶玻璃陶瓷的频率上转换系数C22=1.8025×10-16cm3·s-1,C33=8.1930×10-16cm3·s-1.利用Judd-Ofelt理论和速率方程计算得到样品的上转换效率ηuc为5.687%.结果表明,该材料具有较大的上转换系数和较高的上转换效率,是一种较优异的上转换材料.

The absorption spectrum and upconversion spectrum of Er3 ＋： NaYF4 nanocrystal glass-ceramic were measured at room temperature.The transition probabilities of radiative and nonradiative were calculated based on the absorption spectrum and the Judd-Ofelt theory.Then the upconversion rate equations describing the dynamic process of the system have been established.By solving the rate equations and fitting the simulated curves to the measured data we can estimated upconversion coefficients C22 and C33.The upconversion efficiency is 5.687% calculated by the JuddOfelt theory and rate equations.The results of big upconversion coefficients and high upconversion efficiency are promising and indicate that the Er3 ＋： NaYF4 nanocrystal glass-ceramics are excellent candidates for rare-earth-doped upconversion devices.