The light harvesting systems of photosynthetic organisms harness solar energy by efficient light capture and subsequent transport of the light’s energy to a chemical reaction center. Man-made optical devices could benefit by mimicking these naturally occurring light harvesting processes. Supramolecular organic nanostructures, composed of the amphiphilic carbocyanine dye 3,3’-bis- (2-sulfopropyl)-5,5’,6,6’-tetrachloro-1,1’- dioctylbenzimida-carbocyanine (C8S3), self assemble in aqueous solution to form tubular, double-walled J-aggregates. These J-aggregates have drawn comparisons to light harvesting systems, owing to their optical and structural similarities to the cylindrical chlorosomes (antenna) from green sulfur bacteria. This research utilizes optical spectroscopy and microscopy to study the supramolecular origins of the exciton transitions and fundamental nature of exciton energy transport in C8S3 artificial light harvesting systems. Two J-aggregate morphologies are investigated: well-separated, double-walled nanotubes and bundles of agglomerated nanotubes. Linear dichroism spectroscopy of flow-aligned nanotubes is used to generate the first quantitative, polarized model for the complicated C8S3 nanotube excitonic absorption spectrum that is consistent with theoretical predictions. The C8S3 J-aggregate photophysical properties are further explored, as the Stokes shift, quantum yield, and spectral line broadening are measured as a function of temperature from 77 – 298 K. The temperature-dependent emission ratios of the C8S3 J-aggregate two-band fluorescence spectra reveal that nanotube emission is well described with Boltzmann partitioning between states, while the bundles’ is not. Finally, understanding energy transport in these materials is critical for the proposed use of artificial light harvesting systems in optoelectronic devices. The spatial extent of energy transfer in individual C8S3 J- aggregate structures is directly determined using fluorescence imaging. We find that aggregate structural hierarchy greatly influences exciton transport distances: impressive average exciton migration distances of ~ 150 nm are measured along the nanotubes, while these distances increase to over 500 nm in the bundle superstructures. / text

Understanding the assembly of monomeric components into specific molecular motifs is a central theme in materials and surface engineering. Motif designs, specifically using a controllable template, can yield materials with desired optical or electronic properties. The objective of this thesis is to understand the aggregate size, packing, and monomer orientation for the cationic dye, pseudoisocyanine. These organic molecules assemble into crystals in solution, on planar bilayer templates, and on the membranes of living cells. Pseudoisocyanine J-aggregates were found to form on top of the heterogeneous lipid domains in a phospholipid bilayer. This behaviour is limited to a few headgroup chemistries and lateral packing motifs, allowing one to control aggregation via a combination of these two factors. These aggregates are low-dimensional and display polymorphism. Using atomic force microscopy and visible-light spectroscopy, distinct optical characteristics can be correlated to different bilayer templated J-aggregate morphologies. The molecular packing of a similar J-aggregate crystal was resolved using both atomic force microscopy and selected area electron diffraction. The infrared absorption spectra of different polymorphs also displayed distinct differences. These separate examinations enabled a perspective that clarifies the geometry, packing, orientation, and size of templated J-aggregates. Insights into the templating of J-aggregates on the molecular scale reveals that they are sensitive reporters of membrane phase in adherent cells, and are compatible with established cell biology techniques. Lipid domains in live mammalian cells were visualized using fluorescent J-aggregates in combination with endogenous marker proteins of the endocytic process. Analysis of live cell images and additional biophysical work revealed that pseudoisocyanine J-aggregates formed on domains of the anionic lipid bis(monoacylglycerol)phosphate. Only by using J-aggregates can this lipid be shown to form well-ordered domains during endosomal maturation, leading to multivesicular body formation. These data demonstrate that a correlated optical and topographical approach is necessary to understand the structure of fluorescent molecular assemblies, and form the basis for utilizing such aggregates in a biological context.

Understanding the assembly of monomeric components into specific molecular motifs is a central theme in materials and surface engineering. Motif designs, specifically using a controllable template, can yield materials with desired optical or electronic properties. The objective of this thesis is to understand the aggregate size, packing, and monomer orientation for the cationic dye, pseudoisocyanine. These organic molecules assemble into crystals in solution, on planar bilayer templates, and on the membranes of living cells. Pseudoisocyanine J-aggregates were found to form on top of the heterogeneous lipid domains in a phospholipid bilayer. This behaviour is limited to a few headgroup chemistries and lateral packing motifs, allowing one to control aggregation via a combination of these two factors. These aggregates are low-dimensional and display polymorphism. Using atomic force microscopy and visible-light spectroscopy, distinct optical characteristics can be correlated to different bilayer templated J-aggregate morphologies. The molecular packing of a similar J-aggregate crystal was resolved using both atomic force microscopy and selected area electron diffraction. The infrared absorption spectra of different polymorphs also displayed distinct differences. These separate examinations enabled a perspective that clarifies the geometry, packing, orientation, and size of templated J-aggregates. Insights into the templating of J-aggregates on the molecular scale reveals that they are sensitive reporters of membrane phase in adherent cells, and are compatible with established cell biology techniques. Lipid domains in live mammalian cells were visualized using fluorescent J-aggregates in combination with endogenous marker proteins of the endocytic process. Analysis of live cell images and additional biophysical work revealed that pseudoisocyanine J-aggregates formed on domains of the anionic lipid bis(monoacylglycerol)phosphate. Only by using J-aggregates can this lipid be shown to form well-ordered domains during endosomal maturation, leading to multivesicular body formation. These data demonstrate that a correlated optical and topographical approach is necessary to understand the structure of fluorescent molecular assemblies, and form the basis for utilizing such aggregates in a biological context.

This dissertation describes the assessment and use of carbon optically transparent electrodes (C-OTEs) based on pyrolyzed photoresist films (PPFs) as a platform for spectroelectrochemical investigations. C-OTEs are examined for use in UV-Vis spectroelectrochemistry and electrogenerated chemiluminescence and compared to non-transparent glassy carbon (GC) and the conventional transparent electrode indium tin oxide (ITO). Chapter 1 provides a general overview of transparent electrodes, carbon electrodes, and spectroelectrochemistry. Chapter 2 details a UV-Vis spectroelectrochemical investigation of electrogenerated graphitic oxides (EGO) on the surface of the C-OTE in the presence of KCl. X-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy are used to determine EGO composition. Several supporting electrolytes are investigated to determine the mechanism of EGO formation. Chapter 3 details experiments to electrochemically access the exciton emission from self-assembled double-walled tubular J-aggregates via electrogenerated chemiluminescence (ECL). Optimization of ECL intensity with respect to the coreactant concentration and the supporting electrolyte pH is performed on opaque glassy carbon electrodes. ECL and fluorescence spectra are compared, and C-OTEs are utilized to determine the source of disagreement between the spectra. Chapter 4 describes the preparation and characterization (i.e. transparency, thickness, sheet resistance, rms roughness, and electroactive surface area) of C-OTEs and explores C-OTEs for general use in ECL under a variety of conditions. Simultaneous cyclic voltammograms and ECL transients are obtained for three thicknesses of PPFs and compared to non-transparent GC and the conventional transparent electrode ITO in both front face and transmission electrode cell geometries. Despite positive potential shifts in oxidation and ECL peaks, attributed to the internal resistance of the PPFs that result from their nanoscale thickness, the PPFs display similar ECL activity to GC, including the low oxidation potential observed for amine coreactants on hydrophobic electrodes. Overall, C-OTEs are promising electrodes for spectroelectrochemical applications because they yield higher ECL than ITO in both oxidative-reductive and reductive-oxidative ECL modes, are more stable in alkaline solutions, display a wide potential window of stability, and have tunable transparency for more efficient detection of light in the transmission cell geometry. Future directions for this research are discussed in Chapter 5, which outlines several approaches to designing and improving spectroelectrochemical sensors. / text

The work presented here report findings in (1) infrared detectors based on p-GaAs/AlGaAs heterojunctions, (2) J and H aggregate sensitized heterojunctions for solar cell and photon detection applications, (3) heterojunctions sensitized with quantum dots as low cost solar energy conversion devices and near infrared photodetectors. (1)A GaAs/AlGaAs based structure with a graded AlGaAs barrier is found to demonstrate a photovoltaic responsivity of ~ 30mA/W (~ 450mV/W) at the wavelength of 1.8 mm at 300K. Additionally the graded barrier has enhanced the photoconductive response at 78 K, showing a responsivity of ~ 80mA/W with a D*=1.4×108 Jones under 1V bias at 2.7 mm wavelength. This is an approximately 25 times improvement compared to the flat barrier detector structure, probably due to the improved carrier transport, and low recapture rate in the graded barrier structure. However, these graded barrier devices did not indicate a photoresponse with photoconductive mode at 300K due to high shot noise. Additionally, two generation-recombination noise components and a 1/f noise component were identified. A series of GaAs/AlGaAs multilayer hetero-junction structures were tested as thermal detectors. A superlattice structure containing 57% Al fraction in the barrier and 3 × 1018 cm-3 p-doped GaAs emitter showed the highest responsivity as a thermal detector with a TCR of ~ 4% K-1, at 300K. (2)The photovoltaic properties of heterojunctions with J-/ H- aggregated dye films sandwiched between n– and p-type semiconductors were investigated for potential application as solar cells and IR detectors. Films of cationic dye Rhodamine-B-thiocyanate adsorbed on Cu2O substrate are found to form organized dye layers by self-assembled J- aggregation, resulting in large red-shifts in the photo -response. Additionally, cells sensitized with a pentamethine cyanine dye exhibited a broad spectral response originating from J- and H-aggregates. The photocurrent is produced by exciton transport over relatively long distances with significant hole-mobility as well as direct sensitized injection at the first interface. (3) A ZnO/PbS-QD/Dye heterostructure had enhanced efficiency compared to ZnO/Dye heterostructure as a solar cell. Furthermore, a ZnO/PbS-QD structure has demonstrated UV and NIR responses with 4×105V/W (390 nm) and 5.5×105 V/W (750 nm) under 1V bias at 300K.

The field of organic electronics has received considerable attention over the past several years due to the promise of novel electronic materials that are cheap, flexible and light weight. While some devices based on organic materials have already emerged on the market (e.g. organic light emitting diodes), a deeper understanding of the excited states within the condensed phase is necessary both to improve current commercial products and to develop new materials for applications that are currently in the commercial pipeline (e.g. organic photovoltaics, wearable displays, and field effect transistors). To this end, a model for pi-conjugated molecular aggregates and crystals is developed and analyzed. The model considers two types of electronic excitations, namely Frenkel and charge-transfer excitons, both of which play a prominent role in determining the nature of the excited states within tightly-packed organic systems. The former consist of an electron-hole pair bound to the same molecule while in the later the electron and hole are located on different molecules. The model also considers the important nuclear reorganization that occurs when the system switches between electronic states. This is achieved using a Holstein-style Hamiltonian that includes linear vibronic coupling of the electronic states to the nuclear motion associated with the high frequency vinyl-stretching and ring-breathing modes. Analysis of the model reveals spectroscopic signatures of charge-transfer mediated J- and H-aggregation in systems where the photophysical properties are determined primarily by charge-transfer interactions. Importantly, such signatures are found to be sensitive to the relative phase of the intermolecular electron and hole transfer integrals, and the relative energy of the Frenkel and charge-transfer states. When the charge-transfer integrals are in phase and the energy of the charge-transfer state is higher than the Frenkel state, the system exhibits J-aggregate characteristics including a positive band curvature, a red shifted main absorption peak, and an increase in the ratio of the first two vibronic peaks relative to the monomer. On the other hand, when the charge-transfer integrals are out of phase and the energy of the charge-transfer state is higher than the Frenkel state, the system exhibits H-aggregate characteristics including a negative band curvature, a blue shifted main absorption peak, and a decrease in the ratio of the first two vibronic peaks relative to the monomer. Notably, these signatures are consistent with those exhibited by Coulombically coupled J- and H-aggregates. Additional signatures of charge-transfer J- and H-aggregation are also discovered, the most notable of which is the appearance of a second absorption band when the charge-transfer integrals are in phase and the charge-transfer and Frenkel excitons are near resonance. In such instances, the peak-to-peak spacing is found to be proportional to the sum of the electron and hole transfer integrals. Further analysis of the charge-transfer interactions within the context of an effective Frenkel exciton coupling reveals that the charge-transfer interactions interfere directly with the intermolecular Coulombic coupling. The interference can be either constructive or destructive resulting in either enhanced or suppressed J- or H- aggregate behavior relative to what is expected based on Coulombic coupling alone. Such interferences result in four new aggregate types, namely HH-, HJ-, JH-, and JJ-aggregates, where the first letter indicates the nature of the Coulombic coupling and the second indicates the nature of the charge-transfer coupling. Vibronic signatures of such aggregates are developed and provide a means by which to rapidly screen materials for certain electronic characteristics. Notably, a large total (Coulombic plus charge-transfer) exciton coupling is associated with an absorption spectrum in which the ratio of the first two vibronic peaks deviates significantly from that of the unaggregated monomer. Hence, strongly coupled, high exciton mobility aggregates can be readily distinguished from low mobility aggregates by the ratio of their first two vibronic peaks. Analysis of the spatial dependence of the intermolecular interactions reveals that all four aggregate types (HH-, HJ-, JH-, JJ-) can be achieved by enforcing the appropriate crystalline packing arrangement. Such tunability is possible due of the different length scales over which the natures of the two coupling sources interconvert from J-like to H-like; whereas the nature of the Coulombic coupling is known to be sensitive to displacements on the order of half the molecular length, the nature of the charge-transfer mediated exciton coupling is sensitive to geometric displacements of approximately a carbon-carbon bond length. It is proposed that such sensitivity should allow for fine tuning of the total excitonic coupling via modifications in the packing structure, as determined, for example, by the side chains. Several examples of the different aggregate types are provided throughout this dissertation as the model is used to probe the excited state character of several relevant conjugated organic systems. Such examples include pentacene and 7,8,15,16-tetraazaterrylene (TAT) along with several derivatives from the perylene family. / Chemistry

Diese Arbeit beschäftigt sich mit dem Wachstumsmechanismus von Silberjodid Nanodrähten. Das Wachstum wurde über einen Zeitraum von Minuten bis hin zu Tagen untersucht. Im frühen Stadium bilden sich Silbernanopartikel innerhalb der Farbstoffröhren, welche als Keime für das weitere Wachstum von isolierten Drahtstücken dienen. Der Durchmesser dieser Drähte wird durch den Innendurchmesser der Röhren definiert. Im letzten Stadium wachsen diese Drahtstücke zusammen bis sie das gesamte Aggregat füllen. Dieser Wachstumsprozess impliziert einen Transport von Silber Ionen durch die Wand der Röhre. Das Wachstum der Drähte setzt sich weiter fort nachdem das Template gleichmäßig mit Drähten gefüllt ist und zerstört die Röhren in der Folge. Die Kristallstruktur der Drähte wurde sowohl mit hochauflösender Elektronenmikroskopie als auch Elektronenbeugung untersucht. Das Silberjodid konnte aufgrund seiner charakteristischen Wurtzite Struktur in der beta-Phase identifiziert werden. Da der Lösung nur Silbernitrat beigesetzt wurde, konnte die Quelle der Jod-Ionen als Verunreinigung im Farbstoffpulver ausgemacht werden. Das fragmentierte Wachstum der Drähte von verschiedenen Startpunkten aus führt zu Kristallen mit einkristallinen Domänen von mehr als 100 nm Länge. Eine bevorzugte Orientierung der Kristallstruktur relativ zur Aggregatachse wurde gefunden und durch die Molekülstruktur der Aggregate erklärt. Basierend auf diesen Ergebnissen wurde ein Model zum Wachstum von Silberjodid Nanodrähten im Inneren eines röhrenförmigen Molekülaggregats entwickelt. Es wurde angenommen, dass das Wachstum an Silberkeimen beginnt, die durch Photooxidation der bereits vorhandenen Jod Ionen mit Silber Ionen während der Belichtung der Probe gebildet werden. Diese Silberkeime ermöglichen die Bildung von stabilen Silberjodid Kristalliten und das nachfolgende Wachstum zu Drähten. Die Ergebnisse zeigen einen möglichen Weg zur Synthese von Metall-Halogenid Strukturen innerhalb von Farbstoffröhren. / This thesis reports on the growth mechanism of silver iodide nanowires as revealed by conventional as well as cryogenic transmission electron microscopy. The growth, initiated by short illumination with UV light, has been observed over time scales ranging from minutes to days. In an early stage, within the tubular aggregates nanoparticles are formed which act as seeds for continuous growth of separate pieces of wires. The diameter of the wires is determined by the inner diameter of the tubes. In the final state, the pieces of wire totally fill the aggregate. The growth process indicates transport of at least silver ions through the tubular wall membrane. After homogeneously filling the template the wires grow onwards over the diameter of the nanotubes, destroying it in the process. The crystal structure of the wires was investigated by means of high resolution transmission electron microscopy and selected area electron diffraction. The silver iodide could be clearly identified in its beta-phase by its typical wurtzite structure. Since only silver nitrate was added to the solutions, the source of the iodide ions could be attributed to impurities within the dye powder itself. The fragmented growth of the wires from separate seeds leads to nanowires consisting of single crystalline domains exceeding 100 nm in length. A preferential orientation of the crystal lattice planes with respect to the aggregate axis was observed which is explained by the molecular structure of the aggregates. Based on these findings a model for the growth of silver iodide nanowires within the inner space of the tubular molecular aggregate is presented. The growth is assumed to start at silver seeds that are formed due to photo-oxidation of the already present iodide ions by the silver ions during the illumination of the sample. These silver seeds facilitate nucleation of silver iodide and subsequent growth into wires.

Les polymères semi-conducteurs semicristallins sont utilisés au sein de diodes électroluminescentes, transistors ou dispositifs photovoltaïques organiques. Ces matériaux peuvent être traités à partir de solutions ou directement à partir de leur état solide et forment des agrégats moléculaires dont la morphologie dicte en grande partie leurs propriétés optoélectroniques. Le poly(3-hexylthiophène) est un des polymères semi-conducteurs les plus étudiés. Lorsque le poids moléculaire (Mw) des chaînes est inférieur à 50 kg/mol, la microstructure est polycristalline et composée de chaînes formant des empilements-π. Lorsque Mw>50 kg/mol, la morphologie est semicristalline et composée de domaines cristallins imbriquées dans une matrice de chaînes amorphes. À partir de techniques de spectroscopie en continu et ultrarapide et appuyé de modèles théoriques, nous démontrons que la cohérence spatiale des excitons dans ce matériau est légèrement anisotrope et dépend de Mw. Ceci nous permet d’approfondir la compréhension de la relation intime entre le couplage inter et intramoléculaire sur la forme spectrale en absorption et photoluminescence. De plus, nous démontrons que les excitations photogénérées directement aux interfaces entre les domaines cristallins et les régions amorphes génèrent des paires de polarons liés qui se recombinent par effet tunnel sur des échelles de temps supérieures à 10ns. Le taux de photoluminescence à long temps de vie provenant de ces paires de charges dépend aussi de Mw et varie entre ∼10% et ∼40% pour les faibles et hauts poids moléculaires respectivement. Nous fournissons un modèle permettant d’expliquer le processus de photogénération des paires de polarons et nous élucidons le rôle de la microstructure sur la dynamique de séparation et recombinaison de ces espèces. / Microstructure plays a crucial role in defining the optoelectrical properties of conjugated polymeric semiconductors which can be used in light harvesting and generating devices such as organic light emitting diodes, field effect transistors or photovoltaic devices. These polymers can be processed from solution or solidstate and form photophysical aggregates, consequently providing a complex network which controls the fate of any photogenerated species. poly(3-hexylthiopene) is one of the most studied polymeric semiconductor. In this material, the molecular weight (Mw) of the polymer governs the microstructure and highly impact the optical and electronic properties. Below Mw≈ 50 kg/mol, the polymer chains forms polycrystalline domains of π-stacked molecules while high Mw (>50 kg/mol) consists of a two-phase morphology of molecularly ordered crystallites that are embedded in amorphous regions. Such morphology provides a bidimensionnal network hosting both neutral excitations, known as Frenkel excitons, and polarons. By means of steady-state and ultrafast spectroscopy experiment and backed up theoretical modeling, we demonstrate that the spatial coherence of such excitations are anisotropic in the lattice and depends on the Mw of the polymer, providing a deep understanding of the interplay between interchain (excitonic) and intrachain coupling in polymer aggregates. Moreover, we show that direct excitation at the interface between molecularly ordered and amorphous regions generates tightlybound charge pairs which decay via quantum tunneling over >10 ns. The yield of delayed photoluminescence arising from the recombination of those charge pairs varies between ∼10% and ∼40% for low and high Mw films respectively. We provide a quantitative model that describes the photogeneration process of those geminate polaron pairs and determine the role of the microstructure in the charge separation and recombination processes.

In dieser Arbeit wurden spektroskopische und strukturelle Untersuchungen an chiralen und achiralen supramolekularen Nanoarchitekturen von J-Aggregaten achiraler Cyaninfarbstoffe durchgeführt. Als Modellsysteme wurden Tetrachlorobenzimidacarbocyanin- Farbstoffe mit unterschiedlichen 1,1´-Dialkyl- und 3,3´-Bis-acidoalkyl-Gruppen verwendet. Zur Charakterisierung der Nanostrukturen wurden statische spektroskopische Methoden - UV/Vis-Spektroskopie, Circulardichroismus (CD)- und Fluoreszenzspektroskopie -, Röntgenkristallstrukturanalyse,sowie kryogene Transmissionselektronenmikroskopie (Cryo-TEM) verwendet. Die delikate Balance der Wechselwirkungskräfte, wie z. B. hydrophobe Wechselwirkung, Dispersionswechselwirkung, sowie Wasserstoffbrücken, führt bei der J-Aggregation von strukturell ähnlichen achiralen Chromophoren zu "chiralen" Superhelices und achiralen nanoskopischen Bändern. Durch Kombination der hydrophoben und hydrophilen Eigenschaften von Tensiden mit den unikalen Eigenschaften von J-Aggregaten entstehen Nanoröhren und Vesikel. Diese Nanostrukturen sind daher vielversprechende Kandidaten für künstliche Lichtsammel- und Antennensysteme. / In this work spectroscopic and structural investigations were performed on chiral and achiral supramolecular nanoarchitectures of J-aggregates of achiral cyanine dyes. Tetrachlorobenzimidacarbocyanine dyes with different 1,1´-Dialkyl- and 3,3´-Bis-acidoalkyl- substituents were used as model systems. To characterize these nanoarchitectures static spectroscopic methods - UV/vis-spectroscopy, circular dichroism (CD)- and fluorescence-spectroscopy -, x-ray crystal structure analysis, as well as cryogenic transmission electron microscopy (cryo-TEM) were used. The delicate balance of intermolecular forces, like hydrophobic interaction, dispersion forces, as well as hydrogen bonds, leads by J-aggregation of structural similar achiral chromophores to "chiral" superhelices and achiral nanoscopic ribbons. By combination of the hydrophobic and hydrophilic properties of surfactants with the unique properties of J-aggregates nanotubules and vesicles are built. These nanostructures are hopeful candidates for artificial antenna and light harvesting systems.

Cette thèse expérimentale s’est attachée à l’étude des effets induits par l’extension spatiale desplasmons de surface sur l’émission de matériaux organiques et inorganiques. Le système estformé d’un ensemble d’émetteurs localisés émettant principalement des plasmons de surfacedélocalisés. Dans un premier temps, nous nous sommes intéressés à l’imagerie par microscopieplasmon, technique de plus en plus utilisée dans divers domaines, notamment la biologie. Nousavons montré que l’émission détectée en un point provient essentiellement de l’environnementet non du point observé, définissant ainsi un cercle d’influence lié à la longueur de propagationdu plasmon de surface. Quand le plasmon interagit plus fortement avec des émetteurs, ilpeut entrer en régime de couplage fort. Ce couplage fort se traduit par un changement dansles énergies du système et par l’apparition de nouveaux états hybrides excitons-plasmons, lespolaritons. Les différents émetteurs localisés (des chaines de colorants agrégés) ne sont alorsplus indépendants entre eux. Des mesures de diffusion montrent un effet collectif induit par lecouplage fort. Ces expériences ont été confirmées par des mesures de cohérence spatiale, réaliséesen ajoutant une expérience de fentes d’Young au dispositif de microscopie plasmon. Ilapparait qu’un état cohérent étendu sur plusieurs microns se forme, conformément aux prévisionsthéoriques. L’ensemble d’émetteurs se comporte alors comme une macromolécule, dontl’interaction est induite par le plasmon de surface. / This experimental thesis studies effects induced by the spatial extension of surface plasmonpolaritons on the emission properties of organic and inorganic materials. First, we focused onleakage radiation microscopy images, a technic which is now widely used in a lot of differentscientific fields, as biology for exemple. We showed that the detected emission at a given point ofthe fluorescence image of an assembly of emitters mostly comes from the environment and notfrom the observed point, defining an influence circle related to the surface plasmon propagationlength. When the surface plasmon strongly interact with emitters, the strong coupling leadsto energy modifications in the system and new hybride states excitons-plasmons appear calledpolaritons. All the different localized emitters (aggregated dye chains) are not independantanymore. Diffusion measurments showed a collective effect induced by the strong-coupling.Two Young’s slits experiment added on the optical system confirm that an extended coherentstate of several micrometers is created as predicted by theory. All emitters behave as only onemacromolecule where the interaction is mediated by the surface plasmon.