Green Emission Of Tb3 Research Articles

Synthesis, studies and luminescent properties of terbium oxide-doped LaMn0.9Zn0.1O3+d nanoperovskite by sol–gel method

In this research, we report on the characterization of La1−xTbxMn0.9Zn0.1O3+d (LTMZ) (0.0≤x≤0.32). Nanoparticles with high surface area were synthesized by the polymerized complex method based on the Pechini-type reaction. High-quality nanopowders with controlled stochiometry and microstructure were prepared in the temperature range of 700–800 °C for 6 h, with mean particle sizes of approximately 18.35 nm. The synthesized materials were characterized by X-ray powder diffraction, fourier transform infrared spectrometry and photoluminescence (PL). PL measurements showed the characteristic green emission of Tb3+ ions in crystalline LTMZ powders due to the 5D 4→7F J transitions of the 4f electrons of Tb3+ ions. The structure, homogeneity and particle size of the obtained compounds during different stages were investigated by scanning electron microscopy.

Optical Properties of Tb[sup 3+] Ion in LnP[sub 3]O[sub 9] (Ln=Y, Gd) Host Matrix

Photoluminescence measurements of polyphosphate phosphors LnP(3)O(9): Tb3+ (Ln = Y, Gd) indicated that the phosphors exhibited bright-green emission at 544 nm under 147 nm excitation. Host absorption bands in region from 120 to 174 nm were observed which showed that the green emission of Tb3+ ion in LnP(3)O(9) (Ln = Y, Gd) under vacuum ultraviolet excitation was due to the energy transfer from the hosts. In addition, the observed Tb3+ f-d transitions at 212, 249, and 260 nm were well consistent with the values calculated from the Dorenbos' expression. (c) 2007 The Electrochemical Society.

Luminescence properties of terbium doped poly(acrylic acid) containing 1,10-phenanthroline and 2,2′-bipyridine

Abstract Tb 3+ -doped poly(acrylic acid) was synthesized by polymerization in aqueous solution of the monomer partially neutralized with Tb 2 O 3 , using potassium persulfate as initiator. Besides, samples containing Tb 3+ and 1,10-phenanthroline (Phen) or 2,2′-bipyridine (Bipy) ligands were synthesized. 13 C NMR confirmed the monomer modification and coordination of ligands to Tb 3+ . The doped polymer was characterized by Fourier transform infrared (FT-IR) and luminescent spectroscopy. The results showed clear evidence of the coordination between the dopant cations and the carboxylate anions from the polymer, which were formed during the partial neutralization of the monomer prior to polymerization, and confirmed the coordination of Phen or Bipy ligands to Tb 3+ . On the other hand, the broadening and the relatively high intensity of the 5 D 4 → 7 F 5 green emission of Tb 3+ indicate that the dopant ions are uniformly distributed in low symmetry coordination sites into the polymer matrix. Additionally, the complex formation of Tb 3+ and Phen or Bipy resulted in a prominent enhancement in the Tb 3+ emissions attributed to antenna effect, defined as the excitation of the ligands by light absorption and efficient energy transfer from the ligands to the Tb 3+ ions. The luminescent results showed that, for these polymeric materials, the antenna effect of Phen is even better than that of Bipy.

Photoluminescence due to efficient energy transfer from Ce 3+ to Tb 3+ and Mn 2+ in Sr 3Al 10SiO 20

Sr 3Al 10SiO 20, doped with Ce 3+, Tb 3+, Eu 2+, (Ce 3+ + Tb 3+), (Ce 3+ + Mn 2+), (Eu 2+ + Tb 3+) and (Eu 2+ + Mn 2+) are prepared by wet-chemical route and energy transfer from Ce 3+ to Tb 3+ or Mn 2+ are investigated. The spectrum of Sr 3Al 10SiO 20:Ce 3+ shows single emission band at blue–violet region indicating the weak spin-orbit coupling of the ground state of Ce 3+. Tb 3+ doped Sr 3Al 10SiO 20 yields both the blue emission 5D 3– 7F J ( J = 3, 4, 5, 6) and green emission 5D 4– 7F J ( J = 3, 4, 5, 6) of Tb 3+. However, the relative intensity of 5D 4– 7F J transitions increases with concentration due to cross-relaxation between two interacting Tb 3+ centers. The green emission of Tb 3+ is remarkably enhanced due to energy transfer from Ce 3+ to Tb 3+ when present together in Sr 3Al 10SiO 20. The energy transfer phenomenon is also observed for Ce 3+ and Mn 2+ co-doped Sr 3Al 10SiO 20 indicating that Ce 3+ ion acts as a sensitizer in Sr 3Al 10SiO 20 independent of the activator. Sr 3Al 10SiO 20:Eu 2+ shows broad emission band with the maximum in the blue–green region. However, Eu 2+ does not act as a sensitizer of luminescence when co-doped with Tb 3+ or Mn 2+. This might be because of the existence of Eu 2+ emission level at lower energy than the absorption energy level of Tb 3+ as well as Mn 2+ which does not allow the spectral overlap between the emission spectra of Eu 2+ and the absorption spectra of Mn 2+ or Tb 3+ to induce sensitized luminescence.

Synthesis, characterization and luminescence properties of Tb 3+ and Eu 3+-doped poly(acrylic acid)

Tb 3+ and Eu 3+-doped poly(acrylic acid) (PAA) was synthesized by polymerization in aqueous solution of the monomer partially neutralized with various amounts of Tb 2O 3 and Eu 2O 3, using potassium persulfate as initiator. The monomer modification was confirmed by 1H-NMR. The doped polymer was characterized by 1H-NMR, Fourier transform infrared (FT-IR) and luminescent spectroscopy. The NMR and FT-IR results show clear evidence of the coordination between the dopant cations and the carboxylate anions, which are formed during the partial neutralization of the monomer prior to polymerization. On the other hand, the polymer phosphorescence intensity decreased as the Eu 3+ concentration was increased due to the complex formation. Additionally, the inhomogeneous broadening and the relative intensity of the 5D 0→ 7F 1,2 transitions of Eu 3+ ions, and also, the relatively high intensity of 5D 4→ 7F 5 green emission of Tb 3+, indicate that the dopant ions are uniformly distributed in low symmetry coordination sites. Besides, when both dopants are incorporated to the polymer, the Eu 3+ ions quench the luminescence of Tb 3+, indicating an efficient energy transfer from Tb 3+ to Eu 3+.

Luminescence and energy transfer phenomena of several rare earth ions in the CaAl 2B 2O 7

The luminescence properties of Ce 3+, Gd 3+, and Tb 3+ have been investigated in the compound CaAl 2B 2O 7. The single excitation band peaking at about 320 nm and single emission band peaking at about 384 nm for Ce 3+, without the characteristic doublet, are attributed to the extensive crystal-field splitting of 4f ground state. The emission of Gd 3+ consists of well-known sharp lines and two weak bands around 319.5 and 325 nm. These bands are due to the coupling of Gd 3+ with BO 3 3− groups. The green emission of Tb 3+ is considerably sensitized by Ce 3+. Energy transfer from Ce 3+ to Tb 3+ in CaAl 2B 2O 7 is efficient.

Study of the new boron-rich calcium rare earth borate CaLnB 7O 13

Based on the investigation of the B 2O 3-rich portion of the ternary diagram of Ln 2O 3/1b(CaO) 2/1bB 2O 3 (Ln=rare earth ), two novel ternary borates, CaLaB 7O 13 and CaCeB 7O 13, have been prepared. Indexing the X-ray diffraction patterns of the compounds shows that the two borates are isostructural and belong to the monoclinic system. Under UV excitation, Eu 3+, Tb 3+ and Ce 3+ in the borate present red, green and violet fluorescence respectively. The green emission of Tb 3+ is considerably sensitized by Ce 3+ and the energy transfer from Ce 3+ to Tb 3+ in CaLaB 7O 13 is efficient.