Preparation and luminescence of La<sub>2</sub>O<sub>3</sub>:Ln<sup>3+</sup>(Ln<sup>3+</sup>= Eu<sup>3+</sup>, Tb<sup>3+</sup>, Dy<sup>3+</sup>, Sm<sup>3+</sup>, Er<sup>3+</sup>, Ho<sup>3+</sup>, Tm<sup>3+</sup>, Yb<sup>3+</sup>/Er<sup>3+</sup>, Yb<sup>3+</sup>/Ho<sup>3+</sup>) microspheres
作者:Zhenhe Xu、Shasha Bian、Jiaqi Wang、Tao Liu、Liming Wang、Yu Gao
DOI:10.1039/c2ra22480a
日期:——
Multicolor and monodisperse La2O3:Ln3+ (Ln3+ = Eu3+, Tb3+, Dy3+, Sm3+, Er3+, Ho3+, Tm3+, Yb3+/Er3+, Yb3+/Ho3+) microspheres were prepared by a homogeneous precipitation method followed by a subsequent calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), and photoluminescence (PL) spectra were employed to characterize the samples. The results indicate that the La2O3 microspheres can be well indexed to the hexagonal La2O3 phase. In addition, the possible formation mechanism and the chemical reaction of each step to form spherical La2O3 microspheres are proposed according to the concerned analysis. The as-obtained particles show strong light emission with different colors corresponding to different Ln3+ ions under ultraviolet-visible light excitation. Under 980 nm NIR irradiation, the Lu2O3:Ln3+ (Ln3+ = Yb3+/Er3+, and Yb3+/Ho3+) microspheres exhibit characteristic up-conversion emissions of red (Er3+, 2H11/2, 4S3/2, 2H11/2 → 4I15/2), and green (Ho3+, 5F4, 5S2, 5F5 → 5I8), respectively. These merits of multicolor emissions in the visible region endow this kind of material with potential applications in the field of light display systems, lasers, and optoelectronic devices.
通过均匀沉淀法和随后的煅烧过程制备了多色单分散La2O3:Ln3+(Ln3+ = Eu3+、Tb3+、Dy3+、Sm3+、Er3+、Ho3+、Tm3+、Yb3+/Er3+、Yb3+/Ho3+)微球。采用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、傅里叶变换红外 (FT-IR)、热重和差热分析 (TG-DTA) 以及光致发光 (PL) 光谱来表征样品。结果表明,La2O3 微球可以很好地指示六方La2O3 相。此外,根据相关分析,提出了球形La2O3微球可能的形成机理和各步骤的化学反应。在紫外-可见光激发下,所获得的颗粒显示出与不同Ln3+离子对应的不同颜色的强光发射。在 980 nm 近红外辐射下,Lu2O3:Ln3+(Ln3+ = Yb3+/Er3+ 和 Yb3+/Ho3+)微球表现出特征性的红光上转换发射(Er3+、2H11/2、4S3/2、2H11/2 → 4I15/2)和绿色(Ho3+、5F4、5S2、5F5 → 5I8)。可见光区域多色发射的这些优点赋予这种材料在光显示系统、激光器和光电器件领域的潜在应用。