Hu Rongxuan, Ye Song, Wang Huiyun, Zhang Wenjun, Zhang Zhiyuan, Lin Jian, Wang Deping
J Nanosci Nanotechnol. 2015 Jan;15(1):368-72. doi: 10.1166/jnn.2015.9532.
The upconversion luminescent nanoparticles of NaLnF4 (Ln = Y, Gd):Yb3+, Er3+ were prepared through a facile modified solvothermal method, in which the phase (cubic or hexagonal) and size of the NaLnF4 nanoparticles can be well controlled by adjusting Gd3+ content. The Gd3+ content dependent phase transformation and size change were systematically studied by the XRD and TEM measurements. The spectral measurement revealed that both the emission intensity and the intensity ratio of red (4F9/2 -,4 115/2) to green (2H11/2, 4S3/2 --> 4I15/2) are tunable, and a significant increase of the visible upconversion emission intensity can be realized by optimizing Gd3+ content at x = 0.25 under 980 nm excitation. Furthermore, the excitation power dependent red and green emission intensities of Er3+ were measured for various NaLnF4 (Ln = Y, Gd):Yb3+, Er3+ nanoparticles with different Gd3+ content to investigate the influence of the phase and particle size on the upconversion luminescence properties. This research provided a new method to synthesize the upconversion nanoparticles with tunable luminescence properties by adjusting Gd3+ content.
通过一种简便的改进溶剂热法制备了NaLnF4（Ln = Y，Gd）：Yb3 +，Er3 +上转换发光纳米颗粒，其中通过调节Gd3 +含量可以很好地控制NaLnF4纳米颗粒的相（立方或六方）和尺寸。通过XRD和TEM测量系统地研究了Gd3 +含量依赖性相变和尺寸变化。光谱测量表明，红色（4F9 / 2 -，4 115 / 2）与绿色（2H11 / 2，4S3 / 2 - > 4I15 / 2）的发射强度和强度比均可调，并且在980 nm激发下通过优化x = 0.25的Gd3 +含量可以实现可见光上转换发射强度的显著增加。此外，测量了具有不同Gd3 +含量的各种NaLnF4（Ln = Y，Gd）：Yb3 +，Er3 +纳米颗粒的Er3 +的激发功率依赖性红色和绿色发射强度，以研究相和粒径对上转换发光性能的影响。该研究提供了一种通过调节Gd3 +含量来合成具有可调发光性能的上转换纳米颗粒的新方法。
