Coherence Domains in the Radiative Dynamics of Molecular Aggregates

Spano, Frank C.; Kuklinski, J. R.; Mukamel, Shaul; Brumbaugh, Donald V.; Burberry, M. S.; Muenter, Annabel A.

doi:10.1080/00268949108041184

Cited by 9 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The peculiar band broadening and wavelength shift that accompany the chemical oxidation of the J-aggregate provide some clues about the distribution of positive charge within these highly ordered systems. The spectral features shown in Figure are very similar to those obtained in experiments where the average physical size of a J-aggregate is varied in a statistical sense by dilution with a second dye chromophore …”

Section: Resultssupporting

confidence: 74%

Effects of J-Aggregation on the Redox Levels of a Cyanine Dye

Lenhard

Hein

1996

J. Phys. Chem.

View full text Add to dashboard Cite

The effects of J-aggregation on the redox thermodynamics for a cationic cyanine spectral sensitizing dye are investigated. When adsorbed to the surfaces of cubic AgBr microcrystals, both the monomeric and J-aggregate forms of the cyanine dye can be reversibly oxidized with redox solutions containing ferricyanide or molybdicyanide complex. Diffuse reflectance spectra recorded for thin gelatin coatings of the dyed microcrystals after treatment with redox solution show distinct spectral bands associated with the dye and a stable, monooxidized dye radical ion. The fraction of dye oxidized can be accurately varied by simple adjustment of the electrochemical potential of the redox buffer solution. For the J-aggregated dye, the reflectance band for the dye shifts to shorter wavelengths and becomes significantly broadened with increasing fractional degree of oxidation. The formal oxidation potential for the adsorbed dye can be obtained from a Nernstian plot of redox-solution potential E vs log [oxidized dye]/[dye] as constructed from the reflectance spectral data. The results indicate that the one-electron oxidation potential of the monomer on cubic AgBr to be lower than that of the J-aggregate by 74 mV. The energy of the singlet excited state of the J-aggregate is calculated to be lower than that of the monomer by a much larger amount. For the cationic dye in this study, the aggregation-induced changes in redox potential result in dramatic differences in the comparative photoresponses of the monomer and aggregate dye systems.

show abstract

Section: Resultssupporting

confidence: 74%

Effects of J-Aggregation on the Redox Levels of a Cyanine Dye

Lenhard

Hein

1996

J. Phys. Chem.

View full text Add to dashboard Cite

show abstract

“…This observation in conjunction with the higher PLQY suggests that larger coherent domains are present in the lamellar film. [29] By increasing the fluence, the PL intensity increased, concomitant with a slight decrease in the lifetime (Table S2, Supporting Information). In addition, lifetime measurements for lower excitation fluence of 26 nJ cm -2 are shown in Figure S7, Supporting Information.…”

Section: Exciton Dynamics In Platelets and Lamellar Films At Low Tempmentioning

confidence: 99%

Exciton Dynamics and Effects of Structural Order in Morphology‐Controlled J‐Aggregate Assemblies

Anantharaman

Stöferle

Nüesch

et al. 2018

Adv Funct Materials

View full text Add to dashboard Cite

Narrow-band photoluminescence (PL) together with high quantum efficiency from organic molecules is essential for high color purity emitters. Supramolecular assemblies like Jaggregates are promising materials due to their narrow PL signal with full-width at half maximum (FWHM) < 20 nm. However, their micro-crystalline nature and coherent exciton migration results in strong non-radiative exciton recombination at the grain boundaries that diminish the photoluminescence quantum yield (PLQY), and possibilities for improving the crystallinity by tuning the growth mechanism were limited. Here, we demonstrate two distinct routes to grow different J-aggregate morphologies like platelets and lamellar crystals with Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff))

show abstract

“…More recently, interest in low-dimensional selfassembled molecular aggregates has grown. Muenter et al 12,13 have studied the optical properties of mixed aggregates formed from the dye pseudo-isocyanine ͑PIC; 1,1Ј-diethyl-2,2Ј-cyanine͒ and its aza-analog, which have a large frequency detuning (ϳ4500 cm Ϫ1 ) and belong to the persistence-type. These aggregates were adsorbed on AgBr formed in a glassy solution, 14 where the aggregation process is commonly believed to lead to one-dimensional aggregates.…”

Section: Introductionmentioning

confidence: 99%

Absorption spectra of mixed two-dimensional cyanine aggregates on silver halide substrates

Bakalis

Rubtsov

Knoester

2002

The Journal of Chemical Physics

View full text Add to dashboard Cite

Using the coherent potential approximation ͑CPA͒, we study the absorption spectra of two-dimensional molecular aggregates formed from binary random molecular mixtures. In addition to the substitutional randomness, we include Gaussian randomness in the transition frequencies within each of the two classes of molecules. The latter is motivated by the considerable disorder that is typical for two-dimensional aggregates. By comparing to exact diagonalization results for small clusters, we show that the CPA gives an excellent description of the spectra for this kind of disorder, both in the cases of amalgamation and persistence type mixing. Taking into account long-range excitation transfer interactions mediated by the extended molecular transition dipoles, we analyze experimental spectra of amalgamation-type mixed cyanine aggregates adsorbed on AgBr ͕100͖surfaces that are also reported here. We find good agreement between theory and experiment for the position, the width, and the general shape of the absorption line as a function of the mixing ratio. The analysis also allows us to estimate the slip angle characterizing the structure of these aggregates.

show abstract

Coherence Domains in the Radiative Dynamics of Molecular Aggregates

Cited by 9 publications

References 10 publications

Effects of J-Aggregation on the Redox Levels of a Cyanine Dye

Effects of J-Aggregation on the Redox Levels of a Cyanine Dye

Exciton Dynamics and Effects of Structural Order in Morphology‐Controlled J‐Aggregate Assemblies

Absorption spectra of mixed two-dimensional cyanine aggregates on silver halide substrates

Contact Info

Product

Resources

About