ENERGY-TRANSFER PROCESS IN RARE-EARTH-ION DOPED SrTiO3

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3924-3927 ◽  
Author(s):  
SHINJI OKAMOTO ◽  
SHOSAKU TANAKA ◽  
HAJIME YAMAMOTO
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Temperature Dependence ◽  
Oscillator Strength ◽  
Transfer Process ◽  
Emission Intensity ◽  
Energy Transfer Process ◽  
Rare Earth Ions ◽  
Rare Earth Ion ◽  
Pl Spectra

Enhancement of emission intensity of rare-earth-ion doped SrTiO 3 by Al addition has been investigated. In the case of Pr 3+ and Tb 3+, addition of 23-mol% Al intensifies emission by more than 200 times. In contrast, the addition of 20 mol% Al intensifies emission at most by three times in the case of other rare-earth ions. The temperature dependence of PL spectra shows that the energy transfer from carriers to Pr 3+ or Tb 3+ ions is much more efficient than that to other rare-earth ions in SrTiO 3. It can be speculated that the energy transfer in SrTiO 3: Pr 3 or Tb 3+ occurs from carriers to Pr 3+ or Tb 3+ ion via 4f-5d transitions, which are much higher in oscillator strength than 4f-4f transitions.

Up-Conversion White Emission of β-NaYbF4:0.1%Tm3+,0.1%Er3+ under 980 nm Excitation

2014 ◽  
Vol 809-810 ◽  
pp. 697-701
Author(s):  
Tao Pang ◽  
Jing Jing Chen ◽  
Yun Xia Lin ◽  
Yu Ting Shen ◽  
Min Er Zhao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
White Emission ◽  
Color Coordinate ◽  
New Energy ◽  
Rare Earth Doped

Rare-earth doped β-NaYbF4upconversion phosphors were synthesized using a simple hydrothermal procedure. It is found that under 980 nm excitation β-NaYbF4:0.1%Tm are more efficient than β-NaYF4:20%Yb,0.1% that is known as one of the most effective upconversion materials. The unusual result may be related to the particles size. After introducing 0.1%Er3+into the NaYbF4:0.1%Tm lattice, the upconversion white emission with color coordinate of (0.3016,0.3748) is obtained. The investigation of achieving mechanism indicates that besides the energy transfer from Yb3+to Tm3+and Er3+, respectively, there exists a new energy transfer process:3F2,3(Tm3+) +4I11/2(Er3+) →3F4(Tm3+) +2H11/2/4S3/2(Er3+).

REMO4 (RE = Y, Gd; M = Nb, Ta) phosphors from hybrid precursors: Microstructure and luminescence

2008 ◽  
Vol 23 (3) ◽  
pp. 679-687 ◽  
Author(s):  
Xiuzhen Xiao ◽  
Bing Yan
Keyword(s):  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Luminescent Properties ◽  
Concentration Quenching ◽  
Emission Lines ◽  
Rare Earth Ion ◽  
Red Emission ◽  
Characteristic Emission

In this paper, YNbO4:0.05Tb3+ and GdTaO4:0.05Eu3+ phosphors were chosen to study the influence of the firing temperature on the phase and morphologies using novel modified in situ chemical coprecipitation technology. Results show that until the temperature reaches 1000 °C, the formation of YNbO4 and GdTaO4 were realized; with the increasing firing temperatures, those samples present better crystalline structure and better morphologies. The luminescent properties of Eu3+ and Tb3+ have shown that after calcinations at 1000 °C, the intensity of Eu3+ and Tb3+ increases strongly with the increasing of the calcinations temperature, while remaining relatively unchanged at the temperatures ranging between 600 and 800 °C. Furthermore, other rare earth ion doped GdTaO4 and Y1−xGdxTaO4:5 mol% Eu3+ with the different yttrium content were also synthesized after calcinating at the preferable temperature using the same method. The photoluminescence of Y1−xGdxTaO4:5 mol% Eu3+ revealed that the red emission intensity of Eu3+ increases with the increasing of gadolinium content, indicating that Gd ion plays an important role in the energy transfer process. Also, the concentration quenching has been studied in the GdTaO4:Eu3+/Dy3+ systems. Moreover, the characteristic emission lines of Tb3+, Pr3+, and Er3+ in GdTaO4 were observed, showing that the energy transfer process appears between host and those activators.

Energy-Back-Transfer Process in Rare-Earth Doped AlGaN

2005 ◽  
Vol 866 ◽  
Author(s):  
A. Wakahara ◽  
T. Fujiwara ◽  
H. Okada ◽  
A. Yoshida ◽  
T. Ohshima ◽  
...  
Keyword(s):  
Rare Earth ◽  
Temperature Dependence ◽  
Transfer Process ◽  
Decay Time ◽  
Thermal Quenching ◽  
Rare Earth Ions ◽  
Transfer Model ◽  
Time Resolved ◽  
Peak Energy ◽  
Back Transfer

AbstractTemperature dependence of time-resolved photoluminescence (PL) properties for rare-earth ions (REIs: Eu, Tb, and Er) implanted AlxGa1-xN (x=0∼1) is investigated. Thermal quenching for RE-related PL becomes small when increasing the Al contents. The PL decay time of REIs used in the present work becomes shorter when increasing the temperature and/or PL peak energy. The temperature dependence of PL intensity and the decay time are analysed by assuming phonon assisted energy-back-transfer model, in which the energy in REIs escape to trap levels. From the results, the improvement of PL properties can be well explained by the model, in which the activation energy for energy-back-transfer process is increased as increasing the Al contents.

Influence of Pressure on 5d → 4f Emission Transitions of Ce3+

2001 ◽  
Vol 667 ◽  
Author(s):  
Garry B. Cunningham ◽  
Yongrong Shen ◽  
Kevin L. Bray ◽  
Ulisses R. Rodriguez Mendoza
Keyword(s):  
High Pressure ◽  
Energy Transfer ◽  
Band Structure ◽  
Transfer Process ◽  
Emission Intensity ◽  
Energy Transfer Process ◽  
Low Pressure ◽  
Red Shift ◽  
The Other ◽  
Exciton Recombination

ABSTRACTHigh pressure is used to tune the emission and band structure of the phosphors Ce3+:Lu2S3 and Ce3+:Lu2SiO5. A significant red shift of the broad 5d → 4f emission of Ce3+ was observed in both phosphors. In Ce3+:Lu2S3, we also observed a significant decrease in the emission intensity of Ce3+ and attribute the quenching to a pressure-induced electronic crossover of the Lu2S3 conduction bandedge with the emitting 5d state of Ce3+. In Ce3+:Lu2SiO5, two Ce3+ sites are present and we observed energy transfer from one site (Ce(2)) to the other (Ce(1)) at low pressure. At high pressure, the energy transfer ceases and emission is no longer observed from the Ce(1) site. We propose an exciton recombination model of the energy transfer process.

Tunable color emission based on the activator shell thickness of multilayer core–shell nanoparticles under double NIR excitation

CrystEngComm ◽  
2019 ◽  
Vol 21 (28) ◽  
pp. 4175-4183
Author(s):  
Zhaojing Ba ◽  
Yuansuo Zheng ◽  
Min Hu ◽  
Lei Fu ◽  
Yida He ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Transfer Process ◽  
Shell Thickness ◽  
Energy Transfer Process ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles ◽  
Color Emission

Rare earth luminescent nanomaterials are hot topic due to their unique fluorescence properties. Effective spectral regulation could be achieved by adjusting the coating thickness to affect the energy transfer process in core–shell structure.

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