Controllable Synthesis and Luminescence Properties of La(OH)₃ and La(OH)₃:Tb³⁺ Nanocrystals with Multiform Morphologies

Abstract

One‐dimensional La(OH)3 nanocrystals with multiform morphologies have been successfully synthesized by a facile hydrothermal process without using any surfactant, catalyst, or template. It can be found that the pH values of the initial solutions and the alkaline sources play a crucial role in controlling the morphologies of the products. The possible formation process of the 1D samples was investigated in detail. Furthermore, the as‐prepared Tb3+‐doped La(OH)3 samples show a strong green emission corresponding to 5D4–7F5 transition of the Tb3+ ions under ultraviolet or low‐voltage excitation. The experimental results indicate that the luminescence properties of the as‐obtained phosphors are dependent on their morphologies and sizes. As a result of the unique luminescence properties and controllable morphology and size, these phosphors may find potential applications in fields such as optoelectronic and nanoscale devices or biological technology.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Facile and Controllable Synthesis of Monodisperse CaF2 and CaF2:Ce3+/Tb3+ Hollow Spheres as Efficient Luminescent Materials and Smart Drug Carriers

“…The phase, morphology, and structure of the Ce 3 + /Tb 3 + -doped CaF 2 samples are identical with those of the pure CaF 2 sample, as confirmed by XRD, SEM, and TEM studies on CaF 2 :Ce 3 + /Tb 3 + samples prepared at 180 8C and pH 6.5 for 24 h (see Figure S5 in [44] No other peaks can be detected in the XRD pattern, and the slight change in lattice parameter confirms that the Ce 3 + and Tb 3 + ions have been effectively incorporated into the CaF 2 host lattice. The SEM and TEM images (see Figure S5b and c in the Supporting Information) show that the average size, morphology, and hollow structure of CaF 2 :Ce 3 + /Tb 3 + (pH 6.5) are almost identical with those of the pure CaF 2 counterparts (Figure 2) Figure 8.…”

Controlled synthesis of different multilayer architectures of GdBO3:Eu3+ phosphors and shape-dependent luminescence properties

“…3). On the other hand, the morphology and size of the lanthanide ions doped luminescent materials cannot affect the characteristic spectra due to intra-4f transitions, but may influence the emission intensity resulting from the change in their specific surface area [37]. The large surface area introduces a large number of defects into the phosphor crystal, resulting in a serious drawback on the PL intensity of the phosphors.…”

Syntheses and optical properties of monodisperse BaLnF5 (Ln=La–Lu, Y) nanocrystals

“…Lanthanide (Ln 3+ ) doped rare earth (RE) compounds, such as oxides, fluorides, vanadates and phosphates, have gained increasing attention due to their novel electronic and optical properties arising from the 4f electrons [1][2][3][4][5][6][7], as well as their potential applications in many fields, such as vivo photodynamic therapy of cancer [8], bioimaging [9], volumetric three-dimensional displays [10] and solar cells [11]. Among them, rare earth fluorides have been widely investigated, because they possess crystal lattices of low phone energy, which decreases the non-radiative relaxation probability and thus results in relatively high luminescence efficiency for the doped Ln 3+ ions [12].…”