Luminescence and Energy Transfer Properties of Gd³⁺ and Tb³⁺ in LaAlGe₂O₇

Abstract

The novel phosphors of LaAlGe 2 O 7 doped with Gd 3+ and Tb 3+ were synthesized, and their luminescence properties were investigated. In Tb 3+ -activated LaAlGe 2 O 7 , the unusual excitation spectra showed only intense f-f transition of Tb 3+ ions around the near-UV region, whereas the 4f-5d transition could be neglected. In the Gd 3+ -Tb 3+ -activated system, the decay time of Tb 3+ emission under Gd 3+ excitation at the 6 I J energy level was longer than that measured under direct Tb 3+ excitation at the 5 L 10 energy level, which reinforces the existence of effective Gd 3+ -to-Tb 3+ energy transfer. In the 5 D 4 decay measurements, time-resolved spectra exhibited a "grow-in" behavior as the Tb 3+ concentration was diluted (<0.03 mol), whereas only a simple exponential decay could be observed at higher (>0.05 mol) Tb 3+ concentrations. Two linear relationships were found between the energy transfer probability (P GdfTb ) and the Tb 3+ concentration, which is clear evidence that there were two kinds of efficient Gd 3+ -to-Tb 3+ energy transfer processes in terms of Tb 3+ concentration.

Manifestation of π–π Stacking Interactions in Luminescence Properties and Energy Transfer in Aromatically-Derived Tb, Eu and Gd Tris(pyrazolyl)borate Complexes

“…Eu 3+ or Tb 3+ ) does not hold for the present compounds. 72,73 In an ideal case with no quenching processes, the q and Φ would both be unity.…”

Tunable white light emitting glass suitable for long-wavelength ultraviolet excitation

“…There is also a band near 370 nm corresponding to the superposition of 7 F 6 → 5 G 6 , 7 F 6 → 5 L 10 and 7 F 6 → 5 D 3 transitions [21][22][23]. Traditionally, it is suggested that the odd crystal field components mix a small amount of opposite-parity wave functions (such as 5d) into the 4f wave functions [14], so that the forbidden 4f-4f transition show a certain level of intensity.…”

Synthesis and Luminescent Properties of Cerium‐, Terbium‐, or Dysprosium‐Doped Gd4Si2O7N2 Materials

“…Branching ratios for yellow and blue originating from 4 F 9/2 were evaluated experimentally by calculating the integrals under the respective emission bands. [40] Ningthoujam [41] has reported that the data for the samples with Dy 3+ concentrations below 15 at.-% were not fitted with a monoexponential decay but, rather, they can be fitted well with a biexponential decay. To understand the behaviour of luminescence decay, we have tried to fit the decay curve of both with a monoexponential and a biexponential decay equation.…”