Novel trichromatic phosphor Co-doped with Eu, Tb in SiO2 gel matrix

Abstract

The Eu, Tb co-doped SiO 2 matrix tricolor fluorescence system was prepared by sol-gel technique. Red emission at 618 nm, green emission at 543 nm and blue emission at 350-500 nm were observed in the PL spectra of the sample, indicating that Eu 3+ , Eu 2+ and Tb 3+ ions coexisted in the matrix. In the co-doped sample, the blue emission of Eu 2+ was much stronger than that of the sample single doped with Eu, which implied that the electron transfer between Eu 3+ and Tb 3+ maybe happened in the SiO 2 matrix. The influences of the annealing temperature and Tb concentration on the PL spectra of the samples were investigated. The optimal doped concentration of Tb was determined to be 0.2% and the optimal annealing temperature 850℃. Annealed at 600 • C, Tb 3+ had a sensitizing effect on Eu 3+ in the SiO 2 matrix, and the emission intensity of Eu 3+ in the Eu, Tb co-doped sample was more than four times that of the single doped sample, which could be attributed to the energy transfer from Tb 3+ to Eu 3+ .tricolor, photoluminescence, sol-gel method, rare earths, electron transfer, energy transfer By the end of the 20 th century, the study on rare earth doped luminescence materials had made great advances; and the theoretical value of quantum efficiency of two-photon luminescence had reached nearly 200% [1] . In recent years, as the single-colored luminescence materials have been well studied, the research is no longer confined to the single-colored case. By doping the rare earth ions, the materials can be activated and emit red, green and blue light simultaneously. The relative intensity of these three colors can be adjusted by changing the preparing conditions to produce a full-colored emission and this is one of the most important and attractive research projects in this area around the world now [2][3][4] .It is well known that the most common valence state of rare-earth ions is the trivalent one. Some ions are inclined to exist in abnormal valence, such as Sm 2+ , Eu 2+ , Yb 2+ and Ce 4+ , Pr 4+ , Tb 4+ . What interested us is that when these trivalent ions are doped in a matrix, they may tend to exchange an electron to get a more stable configuration. However, only in a few cases [5][6][7] , the phenomenon of electron transfer has been reported. According to the electron transfer theory, as the electronic configuration of Eu 3+ and Tb 3+ is conjugate, when they are co-doped in one matrix, the electron transition between Eu 3+ and Tb 3+ would occur and the Eu 2+ ions would be obtained. Thus, Eu 3+ , Eu 2+ and Tb 3+ would exist as activation ions in the same selected suitable matrix, which is an efficient way to obtain a single-matrix co-doped tricolor fluorescence system. So far, there is no report about the electron transfer between Tb 3+ and Eu 3+ in SiO 2 matrix.

Energy Transfer Enhancement in Eu3+, Tb3+‐Doped SiO2 Inverse Opal Photonic Crystals

“…It is reported that energy transfer from the donor Tb 3+ to the acceptor Eu 3+ occurs in SiO 2. The donor Tb 3+ in the excited state returns to the ground state through two mechanisms: fluorescence emission and energy transfer. The interaction of these two mechanisms can be expressed as follows: (A, ground acceptor; A * , excited acceptor; D, ground donor; D * , excited donor)…”

Crystal structure, optical spectroscopy and energy transfer properties in NaZnPO4:Ce3+, Tb3+ phosphors for UV-based LEDs

“…This green emission peak at 543 nm has an extremely narrow full-width at half-maximum (FWHM) of only about 10 nm, which is narrower than the previously reported green luminescence materials used for display, involving Ca 2 YZr 2 (AlO 4 ) 3 :Tb 3+ (>13.5 nm), SiO 2 :Tb 3+ (>20 nm), and in the same order then that reported for LaPO 4 codoped Ce 3+ /Tb 3+ (>7.8 nm). [37][38][39] The PL emission intensity of the Lanthanides (Ln 3+ ) doped phosphors is strongly dependent on the activator's concentration. To gure out the optimal doping concentration of Tb 3+ ions in NZPO host material, a series of Tb 3+ doped NZPO phosphors were prepared and their luminescent properties were also studied.…”

Preparation and characterization of monodisperse spherical particles of X-ray nano-phosphors based on Gd2O2S:Tb

“…For example, Xiong et al [1] studied the influences of Ag and Mg dopants on the thermoluminescence (TL) of Li 2 B 4 O 7 (LBO):Cu phosphor, and the results indicate that proper concentrations of Ag and Mg can enhance the TL of LBO:Cu. Hu et al [2,3] prepared Eu, Tb co-doped and Eu, Dy co-doped SiO 2 materials, and found that both of them are excellent tricolor fluorescence systems. Li et al [4] synthesized Sr 3 SiO 5 :Eu 2+ phosphor for white LED by high temperature solid-state reaction.…”