Factors Affecting the Efficiency of Excited-States Interactions of Complexes between Some Visible Light-Emitting Lanthanide Ions and Cyclophanes Containing Spirobiindanol Phosphonates

Attia, M. S.; Khalil, Mostafa M.H.; Abdel-Shafi, Ayman A.; Attia, G. M.; Failla, Salvatore; Consiglio, Giuseppe; Finocchiaro, P.; Abdel‐Mottaleb, M. S. A.

doi:10.1155/2007/12530

Cited by 8 publications

(6 citation statements)

References 46 publications

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“…High luminescent quantum yield, Φ , is required to maximize solar cell efficiency gains through a DS process. Quantified Φ of Eu(tta) 3 phen in solid thin films is infrequently reported, but it has been shown to be dependent on the doping concentration and on the specific host medium used . Φ is determined using an integrating sphere method , where the number of photons emitted is quantified relative to the total excitation photons absorbed by the sample.…”

Section: Methodsmentioning

confidence: 99%

Large Stokes shift downshifting Eu(III) films as efficiency enhancing UV blocking layers for dye sensitized solar cells

Kennedy¹,

Ahmed²,

Doran³

et al. 2014

Phys. Status Solidi A

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In dye-sensitised solar cells developed to-date, ultraviolet blocking layers (UV-BL) is employed to avoid photocatalysis effects on the dye and consequent reduction in PV energy output over time due to UV exposure in outdoor conditions. Use of a UV-BL increases stability but, power conversion efficiency decreases as incident UV photons are not converted. The organolanthanide complex Eu(tta) 3 phen is examined for inclusion in large Stokes shift downshifting (LSS DS) layers. It is shown that such LSS DS layers can be used as a UV blocking layer in DSSCs. A ray-trace numerical model is used to optimise the thickness and concentration of the LSS DS layers for the specific N719 DSSC. EQE is significantly increased in the UV spectral region compared to DSSCs utilizing a passive, non-luminescent, UV-BL. High Eu(tta) 3 phen film transparency in the visible range minimises DSSC EQE losses at visible wavelengths. The photostability of the blended LSS DS polymer films is not sufficient to be useful for medium-long term outdoor PV applications. However, the results demonstrate that significant efficiency enhancement can be realized. Short circuit current enhancement due to downshifting is demonstrated (~1%) in small scale LSS DS polymer films prepared and attached to DSSC devices, where the specific geometry limits the photon collection efficiency and overall enhancement. Model predictions indicate that 2-3% enhancement is realizable in DSSC minimodules, compared to minimodules using passive, non-luminescent, UV-BL. Predicted enhancement in energy produced in outdoor conditions is 3-5%.

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Section: Methodsmentioning

confidence: 99%

Large Stokes shift downshifting Eu(III) films as efficiency enhancing UV blocking layers for dye sensitized solar cells

Kennedy¹,

Ahmed²,

Doran³

et al. 2014

Phys. Status Solidi A

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“…Luminescent quantum yields must be quantified in solid thin films as real PV cell/LDS devices will require the incorporation of luminescent materials into solid layers. LQY may vary in solid films compared to solution because of the rigidity of the polymer host (Attia et al 2006). Difficulties arise in using the comparative method technique for evaluating the LQY of solid thin films.…”

Section: The Integrating Sphere Techniquementioning

confidence: 99%

Enhancement in solar cell efficiency by luminescent down-shifting layers

Ahmed¹,

Walshe²,

Kennedy³

et al. 2013

Advances in Energy Research

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In this paper, core-shell semiconductor quantum dots (QDs) CdSeS/ZnS with emission at 490 nm and 450 nm were investigated for their use in luminescent down-shifting (LDS) layers. Luminescent quantum yield (LQY) of the QDs measurements in solution proposed that they were suitable candidates for inclusion in LDS layers. QDs were encapsulated in poly(methyl,methacrylate) (PMMA) polymer matrix and films were fabricated of 134 ± 0.05 microns. Selections of organic dyes from BASF Lumogen F range were also investigated for their use as LDS layers; Violet 570 and Yellow 083. The addition of LDS layers containing Violet 570 dye demonstrated a unity LQY when encapsulated within a PMMA matrix. A PV device of an LDS layer of Lumogen Violet 570 deposited on top of a crystalline silicon cell was fabricated where it was demonstrated to increase the efficiency of the cell by 34.5% relative.

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“…Therefore some of our phosphonate-spirobisindanol cyclophanes have been used for studying the efficiency of excited-states interactions between lanthanide ions (Tb 3+ and Eu 3+ ) and the cyclophane moiety. We used as substrates for our complexing studies [ 24 ] macrocycles 2 , 4 and 8 .…”

Section: Lanthanides Complexationmentioning

confidence: 99%

“…The apparent association constant (K app ) of (Tb 3+ and Eu 3+ with 2 , 4 and 8 ) complexes in DMSO were obtained [ 24 ] by using Benesi-Hildebrand -type plot equation 1 . where A o , A c and A obs are the absorbance of the ligand of the complex and of the ligand at various concentrations of the metal ions, respectively.…”

Section: Lanthanides Complexationmentioning

confidence: 99%

“…The luminescence of Ln 3+ -chelates is related to the efficiency of the intramolecular energy transfer between the triplet level of ligand and the emitting level of the ions, which depends on the energy gap between the two levels. In the organic solvents, the energy gap between the ligand triplet levels and the emitting level of the terbium favors the energy transfer process for terbium [ 24 ].…”

Section: Lanthanides Complexationmentioning

confidence: 99%

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New Cleft-like Molecules and Macrocycles from Phosphonate Substituted Spirobisindanol

2008

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We have synthetized medium-sized cyclophanes and macrocycles containing phosphonic groups, directly linked to the aromatic rings of the phanes or as pendant arms, for use as specific receptors for the selective complexation of neutral guests or for complexing lanthanides, as luminescent sensors and for diagnostic bioassays in medicine. Furthermore, because it would be of great interest for biochemistry as well as for pharmacological studies to dispose of preorganized rigid chiral hosts for biorelevant molecules we designed inter alia, some new chiral macrocycles capable of a triple binding mode and we used them for constructing macrocycles that could also be of interest for chiral recognition and chiral separations. Thus, in this paper we shall review the salient aspects of some macrocycles synthetized in our laboratory, all possessing the phosphonate moiety and a spirobisindanol scaffold and able to act as complexing agents for cations and organic substrates. In particular, we shall describe their NMR characterization, their stereochemistry in solution and in the solid state, and their use as chiral receptors for biorelevant molecules. Chiral HPLC resolution of some of them is also reported.

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Factors Affecting the Efficiency of Excited-States Interactions of Complexes between Some Visible Light-Emitting Lanthanide Ions and Cyclophanes Containing Spirobiindanol Phosphonates

Cited by 8 publications

References 46 publications

Large Stokes shift downshifting Eu(III) films as efficiency enhancing UV blocking layers for dye sensitized solar cells

Large Stokes shift downshifting Eu(III) films as efficiency enhancing UV blocking layers for dye sensitized solar cells

Enhancement in solar cell efficiency by luminescent down-shifting layers

New Cleft-like Molecules and Macrocycles from Phosphonate Substituted Spirobisindanol

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