Host-Sensitized Luminescence Properties in CaNb 2 O 6 :Ln 3+ (Ln 3+ = Eu 3+ /Tb 3+ /Dy 3+ /Sm 3+ ) Phosphors with Abundant Colors
2014; American Chemical Society; Volume: 54; Issue: 1 Linguagem: Inglês
10.1021/ic502493c
ISSN1520-510X
AutoresKai Li, Xiaoming Liu, Yang Zhang, Xiaojing Li, Hongzhou Lian, Jun Lin,
Tópico(s)Perovskite Materials and Applications
ResumoA series of Ln3+ (Ln3+ = Eu3+/Tb3+/Dy3+/Sm3+) ion doped CaNb2O6 (CNO) phosphors have been prepared via the conventional high-temperature solid-state reaction route. The X-ray diffraction (XRD) and structure refinement, diffuse reflection, photoluminescence (PL), and fluorescent decay curves were used to characterize the as-prepared samples. Under UV radiation, the CNO host present a broad emission band from about 355 to 605 nm centered around 460 nm originating from the NbO6 octahedral groups, which has spectral overlaps with the excitation of f–f transitions of Eu3+/Tb3+/Dy3+/Sm3+ in CNO:Eu3+/Tb3+/Dy3+/Sm3+ samples. They show both host emission and respective emission lines derived from the characteristic f–f transitions of activators, which present different emission colors owing to the energy transfer from the NbO6 group in the host to Eu3+/Tb3+/Dy3+/Sm3+ with increasing activator concentrations. The decreases of decay lifetimes of host emissions in CNO:Eu3+/Tb3+/Dy3+/Sm3+ demonstrate the energy transfer from the hosts to Eu3+/Tb3+/Dy3+/Sm3+. The energy transfer mechanisms in CNO:Eu3+/Tb3+/Dy3+ phosphors have been determined to be a resonant type via dipole–dipole mechanisms. For CNO:Sm3+, the metal–metal charge transfer transition (MMCT) might contribute to the different variations of decay lifetimes and emission intensity from CNO:Eu3+/Tb3+/Dy3+ samples. The best quantum efficiency is 71.2% for CNO:0.01/0.02Dy3+. The PL properties of as-prepared materials indicate the promising application in UV-pumped white-emitting lighting diodes field.
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