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.

Resonant excitation of Er3+ by the energy transfer from Si nanocrystals

2000 ◽  
Vol 638 ◽  
Author(s):  
Kei Watanabe ◽  
Minoru Fujii ◽  
Shinji Hayashi
Keyword(s):  
Energy Transfer ◽  
Transfer Process ◽  
Quantum Confinement ◽  
Energy Transfer Process ◽  
Exciton Energy ◽  
Si Nanocrystals ◽  
Wide Range ◽  
Exciton Recombination ◽  
Average Size ◽  
Co Doped

AbstractPhotoluminescence (PL) of SiO2 films co-doped with Si nanocrystals (nc-Si) and Er was studied. The average size of nc-Si was changed in a wide range in order to tune the exciton energy of nc-Si to the energy separations between the discrete electronic states of Er3+. PL from exciton recombination in nc-Si and the intra-4f shell transition of Er3+ were observed simultaneously. At low temperatures, periodic features were observed in the PL spectrum of nc-Si. The period agreed well with the optical phonon energy of Si. The appearance of the phonon structures implies that nc-Si which satisfy the energy conservation rule during the energy transfer process can resonantly excite Er3+. The effects of the quantum confinement of excitons in nc-Si on the energy transfer process are discussed.

Laser-Induced Intrinsic and Dye-Sensitized Photoconductivity in β-Carotene Glass

1988 ◽  
Vol 42 (6) ◽  
pp. 1073-1078 ◽  
Author(s):  
Michael Tierney ◽  
David M. Lubman
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Transfer Process ◽  
Laser Intensity ◽  
Organic Dyes ◽  
Energy Transfer Process ◽  
The Other ◽  
Two Photon ◽  
Dye Sensitized ◽  
Β Carotene

Photoconductivity is studied in thin films of β-carotenc glass, an amorphous mixture of β-carotene isomers. Photocurrents are produced by a pulsed dye laser and are on the order of microamperes. The mechanism for production of photocurrent is believed to be two-photon internal photoemission. Photoconduction is also investigated in a variety of organic dyes. These dyes and chlorophyll a are then used to sensitize the photoconduction of β-carotene glass to longer wavelengths than it would normally photoconduct. It is believed that chlorophyll and phthalocyanine donate holes to the carotene after photoexcitation, while the other dyes undergo an energy transfer process. The voltage, laser intensity, and wavelength dependences of the photocurrents are examined and compared with results from earlier studies.

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.

scholarly journals Energy transfer process between two laser compounds coumarin 334 & rhodamine 590

2019 ◽  
Vol 14 (31) ◽  
pp. 61-70
Author(s):  
Nathera Abass Ali AL Tememee
Keyword(s):  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Red Shift ◽  
Acceptor Molecule ◽  
Donor Molecule

In the current research the absorption and fluorescence spectrumof Coumarin (334) and Rhodamine (590) in ethanol solvent atdifferent concentration (10-3, 10-4, 10-5) M had been studied. Theabsorption intensity of these dyes increases as the Concentrationincrease in addition to that the spectrum was shifted towards thelonger wavelength (red shift). The energy transfer process has beeninvestigated after achievement this condition. The fluorescence peakintensity of donor molecule was decrease and its bandwidth willincreases on the contrary of the acceptor molecule its intensityincrease gradually and its bandwidth decreases as the acceptorconcentration increase.

Photochemical properties of enediyne-cored dendrimers bearing naphthalenes at the periphery

2019 ◽  
Vol 97 (2) ◽  
pp. 112-119
Author(s):  
Rina Ichino ◽  
Atsuya Momotake ◽  
Tatsuo Arai
Keyword(s):  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Energy Transfer Efficiency ◽  
The Other ◽  
Isomer Ratio ◽  
Rich Mixture ◽  
Photostationary State ◽  
Photochemical Properties ◽  
Cis Isomer

A novel series of trans and cis enediyne-cored dendrimers bearing naphthalenes at the periphery were synthesized and their photochemical properties were examined. The trans/cis isomer ratio in the photostationary state was dependent on the excitation site in the dendrimers. When the enediyne core was selectively excited, the trans/cis isomer ratio in the photostationary state was either around 50/50 or a cis-rich mixture in all dendrimers due to the larger molar extinction coefficient of the trans-enediynes. On the other hand, when naphthalene was excited, a trans-rich mixture was unexpectedly obtained in higher generation dendrimers even though the energy transfer efficiency was almost quantitative in the trans dendrimers. These results could be explained by the energy transfer process, which was different depending on the geometric isomerism of the enediyne core.

Heat, quantum mechanics and information

2015 ◽  
Vol 10 (2) ◽  
pp. 2692-2695
Author(s):  
Bhekuzulu Khumalo
Keyword(s):  
Information Theory ◽  
Quantum Mechanics ◽  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Process Information ◽  
Double Slit Experiment ◽  
Slit Experiment ◽  
Double Slit

Heat has often been described as part of the energy transfer process. Information theory says everything is information. If everything is information then what type of information is heat, this question can be settled by the double slit experiment, but we must know what we are looking for. 

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