emitter must have a high oscillator strength and a high exciton binding energy, such as the electronic excitations (excitons) in quantum dots [ 45 ], [ 46 ], [ 47 ] and two-dimensional monolayer transition mental dichalcogenides [ 37 ], [ 39 ], [ 40 ], [ 48 ], [ 49 ], [ 50 ], for the realization of SC. The molecular excitation of J-aggregates represents an ideal platform for the formation of exciton polaritons because of their exceptionally high oscillator strength and narrow resonances even at room temperature and in the liquid phase [ 26 ], [ 27 ]. Herein, we use the
J-aggregate structures in crystals of three bisazomethine dyes Shinya Matsumoto*, I, Kazuko Shirai I, Kimiko Kobayashi II, Tatsuo Wada III and Motoo Shiro IV I Department of Environmental Sciences, Faculty of Education and Human Sciences, Yokohama National University, 79-2 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan II Molecular Characterization Team, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan III Supramolecular Science Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa
40 Zeitschrift für Kristallographie 210, 40-43 © by R. Oldenbourg Verlag, München 1995 One-dimensional J-aggregates in crystals of l,7-bis-(dimethylamino)-heptamethinium Perchlorate L. Därme* Freie Universität Berlin, Institute of Physical Chemistry, Takustr. 3, D-14195 Berlin, Germany and G. Reck Bundesanstalt für Materialforschung und -prüfung, Rudower Chaussee 5, D-12489 Berlin, Germany Received December 20, 1993; accepted April 18, 1994 Polymethine dye / J-aggregate / Crystal structure / Heptamethinium Perchlorate Abstract. The simple polymethine dye l,7-bis
Abstract
We report the photobehaviour of a series of eight structurally related arylacetylene derivatives, in solution as well as in pristine and PC61BM blended thin-_lms. The formation of both H- and J-aggregates in the solid state have been demonstrated, and, interestingly, an energy transfer from H-aggregates or/and from residual "unstacked" molecules to J-aggregates has been found, the latter being the only emitting species. The fuorescence quenching by PC61BM at di_erent loadings has been studied in blend films, and it has been found particularly effcient in the case of a symmetrical peripheral substitution of the acetylene derivative core. Preliminary time-resolved measurements in emission (ns resolution) and in absorption (fs resolution) con_rmed the H⟶J energy transfer and underlined the presence of delayed fuorescence from Jaggregates, formed by energy transfer from the long-lived first excited singlet state of H-aggregates. In all cases, a homogeneous surface morphology of thin films
Chemistry Division, and Institute for Nanoscience, Naval Research Laboratory, Washington, DC 20375, USA Abstract: We recently found that certain cyanines form tight complexes with carboxymethyl- amylose (CMA) in aqueous solutions and that in these complexes the cyanine exists as a strongly fluorescent and stable J-aggregate. Cyanine dyes are characterized by their ability to form J-aggregates showing very narrow absorption and fluorescence spectra relative to the monomer. Although they have found uses in sensing applications, the practicability has been limited in many
silver/dye nanoparticles in colloidal solutions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008,326, 204-209. [5] Lim, I.I.S., Goroleski, F., Mott, D., Kariuki, N., Ip, W., Luo, J. and Zhong, C. J., Adsorption of Cyanine Dyes on Gold Nanoparticles and Formation of J-Aggregates in the Nanoparticle Assembly, J. Phys. Chem. B, 2006,110, 6673-6682. [6] Kometani, N., Nakajima, H., Asami, K., Yonezawa, Y., Scheblykin, I. G. and Vitukhnovsky, A. G., Luminescence properties of the J-aggregate of cyanine dyes in multilayer assemblies,J. Luminesc., 2000
-order nonlinear absorption coefficient I 0 The intensity at focal point ( z = 0) L eff Effective thickness Z 0 Rayleigh range S 1 Singlet excited state T 1 Triplet excited state E T (30) Reichardt solvent polarity parameter M Monomer D Dimer K Equilibrium constant υ M Maximum absorption position of monomer (in cm −1 ) υ H Maximum absorption position of H aggregate (in cm −1 ) υ J Maximum absorption position of J aggregate (in cm −1 ) In general, under influence of a continuous wave laser irradiation, a five-level system can be considered as an approximate model for studying
crystallizes in the monoclinic space group P2Jn with a = 778.9(3) pm, b = 1349.4(3) pm, c = 1950.7(3) pm, ß = 101.10(2)°,Z = 4and£>x = 1.345 g • cm-3.R = 0.076 for 2458 unique reflections with I > 2a(I) at 294 K. The 7r-system of the dye cation is polarized by intermolecular interactions resulting in a bond length alternation. Stacks of dye molecules, which corresponds to J-aggregate structures could not be found. Introduction Polymethine dyes are typically characterized by a com- pletely delocalized 7t-electron system, leading to equaliza- tion of the single and double bond
. So a further progress was achieved by using the /-aggregates: com peting nonradiative desactivation processes (o f the excited dye mole cules) were diminished in J-aggregates. 1. Einleitung Die Grundlage jeder photochemischen Speiche rung von Lichtenergie basiert auf der (lichtindu zierten) Energieübertragung und der Ladungstren nung. Die Anforderung an eine erfolgreiche Licht speicherung sind ein schneller Elektronentransfer sowie eine effiziente Ladungstrennung. In der Ver gangenheit wurden viele Versuche unternommen, durch kovalente Verknüpfung von
conditions, J-aggregating molecules [ 17 ], [ 18 ], [ 19 ], dyes [ 20 ], quantum dots [ 21 ], or two-dimensional materials [ 22 ], [ 23 ] placed nearby resonant metallic nanoparticles or nanoparticle arrays, have been shown to give rise to strong plasmon-exciton coupling. More importantly, many interesting effects have been predicted and observed in these systems, including coherent emission [ 17 ], lasing in nanoparticle arrays [ 24 ], [ 25 ], [ 26 ], ultrafast Rabi oscillations [ 27 ], chemical dynamics tuning [ 28 ], coupling with dark excitonic states [ 29 ], and few
