Recently, technological advancement and the promise of next-generation devices have created an overwhelming push for the continued miniaturization of active systems to the micro- and nanometer scale. In this regime, traditional mechanical systems are largely inaccessible and as a result new active or stimuli-responsive materials are required. The work presented in this dissertation provides an understanding of the responsive nature of polymer and biopolymer interfaces especially in contact with metal nanoparticles. This understanding was utilized in conjunction with top-down template-based and self-assembly fabrication strategies to create hybrid protein based films and active polymer-metal hybrids that exhibit large and well-defined modulation of mechanical and optical properties. These materials processing developments represent advancement in the current state of the art specifically in three major areas: 1. template-based top-down control of protein chain conformation, 2. high-throughput synthesis and assembly of strongly coupled plasmonic nanoparticles with modulated optical properties (both near- and far-field), 3. field-assisted assembly of highly mobile and non-close packed magnetic nanorods with capabilities for rapid actuation.

Heterostructures of materials with dramatically different properties are exciting for a variety of devices. In particular, the epitaxial integration of metals with semiconductors is promising for low-loss tunnel junctions, embedded Ohmic contacts, high-conductivity spreading layers, as well as optical devices based on the surface plasmons at metal/semiconductor interfaces. This thesis investigates the structural, electrical, and optical properties of compound (III-V) semiconductors employing rare-earth monopnictide (RE-V) nanostructures. Tunnel junctions employing RE-V nanoparticles are developed to enhance current optical devices, and the epitaxial incorporation of RE-V films is discussed for embedded electrical and plasmonic devices. Leveraging the favorable band alignments of RE-V materials in GaAs and GaSb semiconductors, nanoparticle-enhanced tunnel junctions are investigated for applications of wide-bandgap tunnel junctions and lightly-doped tunnel junctions in optical devices. Through optimization of the growth space, ErAs nanoparticle-enhanced GaAs tunnel junctions exhibit conductivity similar to the best reports on the material system. Additionally, GaSb-based tunnel junctions are developed with low p-type doping that could reduce optical loss in the cladding of a 4 μm laser by ~75%. These tunnel junctions have several advantages over competing approaches, including improved thermal stability, precise control over nanoparticle location, and incorporation of a manifold of states at the tunnel junction interface. Investigating the integration of RE-V nanostructures into optical devices revealed important details of the RE-V growth, allowing for quantum wells to be grown within 15nm of an ErAs nanoparticle layer with minimal degradation (i.e. 95% of the peak photoluminescence intensity). This investigation into the MBE growth of ErAs provides the foundation for enhancing optical devices with RE-V nanostructures. Additionally, the improved understanding of ErAs growth leads to development of a method to grow full films of RE-V embedded in III-V materials. The growth method overcomes the mismatch in rotational symmetry of RE-V and III-V materials by seeding film growth with epitaxial nanoparticles, and growing the film through a thin III-V spacer. The growth of RE-V films is promising for both embedded electrical devices as well as a potential path towards realization of plasmonic devices with epitaxially integrated metallic films. / text

A variety of benefits motivate the development of epitaxial metals, among which include the ability to design fully integrated layer structures where metallic films and nanostructures can be embedded into the cores of optoelectronic devices. Applications include high-performance tunnel-junctions, epitaxial transparent Ohmic contacts, photomixer material, and thermoelectrics. Additionally, the integration of metallic nanostructures and films into optoelectronic devices has shown potential for improving device performance and functionality through sub-wavelength confinement of plasmonic modes and enhancement of light/matter interactions. The rare-earth monopnictide (RE-V) material system can be integrated epitaxially with conventional zincblende III-V substrates under normal growth conditions, resulting in high-quality, thermodynamically stable interfaces. The RE-V semimetals span a range of optical, electrical, and structural properties, making them ideal for integration into III-V-based optoelectronic devices and applications. In this dissertation, high-quality epitaxial LuAs, LaAs and La(x)Lu(1-x)As films and nanostructures were grown and characterized for their structural, electrical, optical, and plasmonic properties. Through a sweep of alloy film compositions of the RE-V alloy material La(x)Lu(1-x)As, the ability to produce tunable epitaxial metals was demonstrated, with a range of peak transmission spectra from near- to mid-infrared wavelengths, plasmonic response in the mid-infrared, moderate resistivity, and lattice-matching potential to many relevant III-V substrates. Additionally, there is a great deal of interest in developing techniques to produce optoelectronic devices that are not restricted by substrate lattice constant. Many epitaxial approaches have been tried, with moderate success; however, growing low defect-density heteroepitaxial materials with differing crystal structures and highly-mismatched lattice parameters is extremely challenging, and such structures suffer from poor thermal properties and reliability issues. A general approach is needed for thin metamorphic buffer layers with minimal threading dislocations that simultaneously have low thermal resistance for effective heat-sinking and device reliability. An investigation was conducted into the use of RE-V nanostructure superlattices towards the reduction of dislocation density in highly-mismatched III-V systems. / text

The interaction of an evanescent wave and plasmonic nanostructures are simulated in Finite Element Method. Specifically, the optical absorption cross section (Cabs) of a silver nanoparticle (AgNP) and a gold nanoparticle (AuNP) in the presence of metallic (gold) and dielectric (silicon) atomic force microscope (AFM) probes are numerically calculated in COMSOL. The system was illuminated by a transverse magnetic polarized, total internally reflected (TIR) waves or propagating surface plasmon (SP) wave. Both material nanoscale probes localize and enhance the field between the apex of the tip and the particle. Based on the absorption cross section equation the author was able to demonstrate the increment of absorption cross section when the Si tip was brought closer to the AuNP, or when the Si tip apex was made larger. However, the equation was not enough to predict the absorption modification under metallic tips, especially for a AgNP's Cabs; neither it was possible to estimate the optical absorption based on the localized enhanced field caused by a gold tip. With the help of the driven damped harmonic oscillator equation, the Cabs of nanoparticles was explained. In addition, this model was applicable for both TIR and Surface Plasmon Polaritons illuminations. Fitting the numerical absorption data to a driven damped harmonic oscillator (HO) model revealed that the AFM tip modifies both the driving force (F0), consisting of the free carrier charge and the driving field, and the overall damping of the oscillator beta. An increased F0 or a decreased beta will result in an increased Cabs and vice versa. Moreover, these effects of F0 and beta can be complementary or competing, and they combine to either enhance or suppress absorption. Hence, a significantly higher beta with a small increment in F0 will result in an absorption suppression. Therefore, under a Si tip, Cabs of a AuNP is enhanced while Cabs of a AgNP is suppressed. In contrast, a Au tip suppresses the Cabs for both Au and Ag NPs. As an extension of this absorption model, further investigation of the guided mode and a close by nanostructure is proposed, where the scattered wave off the structure attenuates the guided mode with destructive interference.

Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage – LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit the applicability and impact of the sensor. In spite of the extensive amount of work done in this field, there has been a clear absence of efforts to make LSPR sensors immune to interfering effects. The work presented in this document investigates, both experimentally and numerically, dual- and tri-mode LSPR sensors that utilize the multiple surface plasmon modes of gold nanostructures to distinguish target analyte from interfering bulk and non-specific binding effects. Finally, a series of biosensing experiments are performed to examine various regeneration assays for LSPR sensors built on indium tin oxide coated glass substrate.

À la surface d’un métal, la lumière visible peut se coupler avec les électrons libres pour engendrer une quasi-particule particulièrement intéressante, le plasmon-polariton de surface. Cet objet a pour propriété d’être évanescent dans les directions perpendiculaires à la surface, ce qui en fait un support idéal pour transporter l’information lumineuse à deux dimensions, et sur des échelles sub-longueur d’onde. S’il est excité par une source quantique, il conserve cet aspect quantique du signal, même si des millions d’électrons sont impliqués dans sa propagation.Dans ce manuscrit, je présente les résultats expérimentaux et théoriques obtenus en plasmonique de surface durant mon doctorat. En associant l’utilisation de centres colorés azote-lacune (NV) dans les nanodiamants, qui sont des émetteurs de photons uniques, et d’un microscope optique en champ proche (SNOM), j’ai pu étudier de nombreuses propriétés du centre NV et des plasmons de surface dans les domaines classique et quantique.Notamment, j’ai réalisé une étude complète de la photo-dynamique interne du centre NV, dans différents régimes d’excitation. De plus, j’ai étudié le mode d’imagerie des plasmons de surface qu’est la microscopie à fuite radiative, en mettant en lumière certaines aberrations optiques pouvant survenir dans des conditions de désaccord d’indices optiques. J’ai ensuite effectué des mesures de corrélations spatio-temporelles de plasmons de surface excités par des centres NV, grâce à un système expérimental spécifique que j’ai mis en œuvre.Enfin, je décris dans ce manuscrit les toutes premières études de l’interaction des plasmons avec différentes cavités elliptiques et paraboliques gravées dans le métal, qui ont mené notamment à des mesures de densité locales d’états (LDOS) plasmonique. / On a metal surface, visible light can couple with surface free electrons to form a very interesting quasi-particle, the surface plasmon-polariton. The main property of this object is to be evanescent in the directions perpendicular to the surface. This feature makes the plasmon ideally suited to transport electromagnetic information in two dimensions and on a sub-wavelength scale. If it is excited by a quantum source, it retains this quantum aspect of the signal, even if millions of electrons are involved in its propagation.In this manuscript, I present the experimental and theoretical results obtained during my PhD in surface plasmonics. By combining the use of nitrogen vacancy (NV) color centers in nanodiamonds, which are single photon emitters, and of a scanning near field optical microscope (SNOM), I was able to study numerous properties of the NV center and surface plasmons, both in the classical and quantum regimes.In particular, I have performed a complete study of the internal photo-dynamics of the NV center in different excitation regimes. Moreover, I have studied the leakage radiation microscopy, a dedicated imaging mode in plasmonics , by highlighting some optical aberrations that can arise in conditions of optical index mismatch. Furthermore, I have ran spatio-temporal correlation measurements on surface plasmons excited by NV centers with a specific experimental system I implemented.Finally, I describe in the manuscript the very first studies of the interaction between plasmons and different elliptical and parabolic cavities milled in the metal. This has led to the measurements of the plasmonic local density of states.

Les nanocristaux d'AgInS2-ZnS sont des candidats prometteurs pour le développement de nano-luminophores non-toxiques et performants. Grâce à leur taille et à leur forte absorption, ces nano-luminophores permettent l'exploitation d'effets nano-optiques pouvant augmenter leur efficacité à l'absorption ou à l'émission. Ce document présente, dans un premier temps, une méthode d'analyse qui couple la mesure du rendement quantique à celle du temps de vie de luminescence et permet l'étude des contributions radiatives et non-radiatives des différents mécanismes de luminescence des nanocristaux d'AgInS2-ZnS. En modifiant la taille, la chimie de surface et la structure du cœur de ces nanocristaux, nous construisons un modèle global expliquant le rôle de leur composition et soulignant l'importance de leur surface. De nouvelles stratégies sont identifiées pour optimiser ces nanomatériaux. Leur application conjointe permet d'envisager des rendements quantiques proches de 90%. Dans un second temps, une méthode de simulation numérique générale a été développée pour prédire l'effet produit par le couplage nano-optique entre une particule plasmonique et un luminophore. Cette méthode a été appliquée au cas des structures cœur/coquille/coquille (métal/isolant/AgInS2-ZnS) et les configurations optimales du système ont été déterminées. Une nanostructure particulièrement performante permettant de combiner les effets du couplage à l'absorption et à l'émission a été identifiée. Une méthode de synthèse de ces nanostructures est développée. Les résultats expérimentaux obtenus sont en accord à la fois avec la compréhension de la fluorescence des nanocristaux d'AgInS2-ZnS et la prédiction obtenue par simulation. / AgInS2-ZnS nanocrystals are promising materials for the development of non-toxic, highly efficient nano-phosphors. Their size and strong absorption allow them to exploit nano-optical effects potentially enhancing both their absorption and emission processes. This work presents a method combining quantum yield measurements with time resolved emission spectroscopy allowing for the study of both radiative and non-radiative properties of each recombination pathways. Modifying the size, surface chemistry, and core structure of the nanocrystals, we construct a global model explaining the role of their composition and emphasizing the critical aspect of their surface. New strategies are identified to increase the internal quantum yield of these materials. Combining these approaches, it is now possible to expect 90% efficiencies. In a second step, a simulation method was developed to predict the nano-optical effects induced by a plasmonic nanostructure on a given phosphor. We applied this method on core/shell/shell (metal/insulator/AgInS2-ZnS) nanostructures and theoretically determined optimal configurations of the system. A particularly efficient nanostructure achieving coupling on both absorbed and emitted light is identified. Hybrid plasmonic nanostructures are synthesized. Their performances are in accordance with both our understanding of the fluorescence mechanisms of AgInS2-ZnS nanocrystals and the predictions made via simulation.

De par leur petite taille et suivant leur nature, les micro et nanoparticules colloïdales présentent de nouvelles propriétés physiques, tout particulièrement dans le domaine de l'optique (guidage et focalisation sub-longueur d'onde, propagation de plasmons, émission monochromatique...). Toutefois la synthèse chimique de ces micro/nano-objets étant principalement réalisée en phase aqueuse, il devient nécessaire de développer des technologies pour surpasser leur mouvement aléatoire dans le liquide et permettre leur positionnement et leur organisation sur une surface de façon déterministe. Les méthodes d'assemblage par forces de capillarité, consistant à contrôler l'évaporation d'une goutte de suspension colloïdale sur un substrat lithographié, font partie des outils les plus prometteurs. Depuis plusieurs années notre équipe a développée un banc expérimental basé sur l'assemblage thermodynamique par forces de capillarité en milieu confiné. Cette technique a permis la réalisation de structures planaires à base de nano et microparticules diélectriques ou métalliques pour mener des études optiques (couplage plasmonique, nanojet photonique...). Néanmoins, un des défis reste la maitrise de cette technologie pour l'élaboration de structures tri-dimensionnelles diélectriques ou métalliques.C'est dans cette perspective que nous avons développé une technologie permettant la réalisation et le transfert d'architecture 3D de taille et de forme variées, à base de nanoparticules. Deux types d'architectures ont été réalisés : des architectures métalliques constituées de nanoparticules d'or (de diamètre 100 nm), et des structures diélectriques à l'aide d'un mélange de particules de polystyrène fluorescentes (diametre 100 nm).Les propriétés plasmoniques des architectures métalliques ont été étudiées en champ lointain par spectroscopie de diffusion et par luminescence à deux photons. L'influence des caractéristiques structurales des objets sur leur réponse optique ont ainsi pu être évaluées. L'effet du à la structuration en trois dimensions a également été observé sur la réponse en champ proche optique.Les architectures diélectriques présentent quant à elles un potentiel en tant qu'émetteurs polychromatiques dans la gamme spectrale du visible. Une étude spectroscopique de mélanges de particules de trois couleurs différentes (bleu, vert et rouge) a été réalisée afin de déterminer les propriétés spectrales et chromatiques de tels objets, et ainsi donner naissance à une émission polychromatique blanche localisée sur un substrat de silicium.Finalement une approche tout à fait originale a été abordée afin d'utiliser la technique d'assemblage par forces de capillarité en tant que méthode de détection ultra-sensible. Une preuve de concept a alors été obtenue à l'aide de suspensions colloïdales de nanoparticules d'or. / By their small size and according to their nature, colloidal micro and nano-particles exhibit novel physical properties, especially in the field of optics (subwavelength guiding and focusing, plasmon propagation, monochromatic emission...). However, the chemical synthesis of these micro/nano-objects being mainly carried out in aqueous phase, makes it necessary to develop technologies to overcome their random motion in the liquid phase and allow their deterministic positioning and organization on a surface. The capillary assembly methods, consisting in controlling the evaporation of a colloidal droplet on a lithographied substrate, are among the most promising tools. For several years our team has developed a test bench based on the thermodynamic capillary force assembly in a confined environment. This technique has allowed the realization of planar structures based on dielectric or metallic nano and microparticles to conduct optical studies (plasmonic coupling, photonic nanojet...). Nevertheless, one of the remaining challenges is the development of three-dimensional dielectric or metallic structures with the capillary force assembly technique.In this context we have developed a technology for the realization and the transfer of 3D nanoparticles architectures of various sizes and shapes. Two types of architectures have been created : metallic architectures made of gold nanoparticles (100 nm in diameter), and dielectric structures of fluorescent polystyrene particles (100 nm in diameter).The plasmonic properties of the metallic architectures have been studied in far field by scattering spectroscopy and two-photon luminescence. The influence of the structural characteristics of these objects on their optical response could thus be assessed. The effect of the three-dimensional structure has also been observed on the near field optical response.The dielectric architectures present a potential as polychromatic emitters in the visible spectral range. A spectroscopic study of particle mixtures of three different colors (blue, green and red) was performed to determine the spectral and chromatic properties of such objects, and thus give rise to a white polychromatic emission localized on a silicon substrate.Finally, a completely original approach to use the technique of capillary force assembly as an ultra- sensitive detection method was discussed. A proof of concept was then obtained using colloidal suspensions of gold nanoparticles.

Depuis la première observation du phénomène de Diffusion Raman Exaltée de Surface (DRES) en 1974 de nombreuses méthodes ont été développées pour contrôler l'arrangement de nanostructures métalliques sur une surface dans le but d'augmenter le signal de diffusion Raman. La valeur du facteur d'amplification de la DRES résulte principalement de l’accroissement localisé du champ électromagnétique pour des surfaces métalliques nanostructurées. Des études antérieures ont révélé que l'espacement nanométrique entre les nanoparticules constituait des zones de forte exaltation appelées «points chauds». Nous avons développé et breveté une méthode de lithographique assistée par AFM permettant la fabrication de surfaces métalliques. Il a été démontré que cette méthode fournissait une approche relativement simple pour réaliser d’une part des surfaces reproductibles à géométrie contrôlée à l’échelle nanométrique, et d’autre part des surfaces modèles pour étudier l'influence de la géométrie des motifs sur l'effet DRES. Afin d'étudier la relation entre les propriétés optiques et la géométrie de nos systèmes la résonance plasmon localisée de surface (LSPR) et le facteur d'exaltation du champ électrique local ont été simulés par éléments finis. Les zones de forte exaltations ont été localisées sur les nanostructures par microscopie par photoémission d'électrons (PEEM) et l'effet DRES a été démontré en effectuant des mesures Raman avec plusieurs molécules cibles. Les corrélations effectuées entre les résultats de PEEM, les calculs du champ local et les facteurs d’exaltation Raman seront présentées en lien avec les paramètres géométriques des motifs de nanostructures. / Since the first observation of Surface Enhanced Raman Scattering (SERS) in 1974 a variety of methods have been developed to physically control the arrangement of metallic nanostructures onto a surface in order to enhance Raman signals. The magnitude of the SERS enhancement factor is mainly driven by the enhanced local electromagnetic field in nanostructured metal surfaces. Gaps between adjacent nanoparticles give rise to strong enhancement effects, often referred as ‘hot spots’. One way to produce highly efficient SERS substrates is to develop a reproducible system of interacting metal nanostructures capable of high field enhancement.We patented a force-assisted Atomic Force Microscopy lithographic method allowing the fabrication of a metallic substrate. It will be shown that this method also provides a relatively simple approach to realize reproducible patterns with controlled geometry that can be used to study the influence of specific pattern geometry on SERS phenomenon.In order to investigate the relationship between optical properties and pattern geometries, localized surface plasmon resonance (LSPR) and local electric field enhancement are simulated.Whereas electric field enhancement regions (hot spot) have been observed on the top of the nanostructures with PhotoEmission Electron Microscopy (PEEM), SERS effect has been demonstrated by performing Raman measurements using several probe molecules. Correlations between PEEM measurements, Raman exaltation and local field calculations are presented in relation with the geometrical parameters of the nanostructured patterns.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-04T15:25:57Z No. of bitstreams: 1 patriciabarrossantos.pdf: 5111164 bytes, checksum: a7268529a7643972391f0dd226a987a3 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:32:29Z (GMT) No. of bitstreams: 1 patriciabarrossantos.pdf: 5111164 bytes, checksum: a7268529a7643972391f0dd226a987a3 (MD5) / Made available in DSpace on 2017-05-17T13:32:29Z (GMT). No. of bitstreams: 1 patriciabarrossantos.pdf: 5111164 bytes, checksum: a7268529a7643972391f0dd226a987a3 (MD5) Previous issue date: 2016-07-28 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho consistiu na síntese e caracterização de catalisadores plasmônicos nanoestruturados híbridos metal∕semicondutor, para aplicação na fotodegradação do corante têxtil Reactive Black 5 (RB5), utilizando irradiação no visível. Foram sintetizadas nanopartículas de óxido de zinco, cobre (CuNPs) e prata (AgNPs), bem como catalisadores plasmônicos híbridos do tipo Cu∕ZnO e Ag∕ZnO que foram submetidos a diversas técnicas de caracterização como, espectroscopia Raman, UV-VIS, DRX de policristais, MEV e MET. Os processos de fotodegradação foram realizados em um reator labmade, no qual a solução de corante (1×10-5mol L-1) foi irradiada utilizando lâmpada fluorescente (11W) e∕ou incandescente (100W) como fontes de irradiação no visível. A fotodegradação do corante RB5 foi monitorada através de espectroscopia eletrônica no UV-VIS, espectroscopia vibracional Raman ressonante (RR) e intensificada por superfície (SERS), sendo possível observar mudanças relacionadas ao processo de fotodegradação. A espectroscopia no UV-VIS mostrou a queda na intensidade da banda de absorção do grupo cromóforo com o tempo de irradiação; por outro lado, RR e SERS permitiram observar a formação de espécies fluorescentes e mudanças no perfil espectral vibracional. Não ocorreu a fotólise do corante por nenhuma das duas fontes de irradiação utilizadas. AgNPs não promoveram a fotodegradação do RB5, porém nanopartículas de ZnO degradaram cerca de 66% das moléculas de corante, sob irradiação no visível (lâmpada incandescente). Fotocatalisadores plasmônicos do tipo Ag∕ZnO foram utilizados nos processos de degradação do RB5 utilizando ambas as fontes de irradiação no visível, sendo adicionados ao meio do corante de formas diferentes. Quando utilizado diretamente em suspensão e sob irradiação da lâmpada fluorescente o percentual de fotodegradação foi de 97%. Já com a adição do catalisador no estado sólido à solução de corante e sob irradiação da lâmpada fluorescente 72% das moléculas de RB5 foram degradadas. Esse último resultado pode ser comparado ao obtido utilizando ZnO como catalisador, e mostra um ganho de 22% na eficiência catalítica no visível na presença do material plasmônico AgNP/ZnO. / The present work consisted in the synthesis and characterization of plasmonic nanostructured hybrids metal∕semiconductor catalysts, for application on photodegradation of the Reactive Black 5 (RB5) textile dye using visible irradiation. Nanoparticles consisting of zinc oxide, copper (CuNPs) and silver (AgNPs) were synthesized, as well as plasmonics catalysts of Cu∕ZnO and Ag∕ZnO types. The materials underwent several characterizations using techniques such as Raman Spectroscopy, UV-VIS, polycrystal DRX, SEM and TEM. Photodegradation processes were carried out in a labmade reactor, in which a dye solution (1×10-5mol L-1) was irradiated using fluorescent (11W) and∕or glowing (100W) lamp bulb as sources of radiation in the visible range. The photodegradation of the RB5 dye was monitored through electronic spectroscopy UV-VIS, and vibrational spectroscopies resonant Raman (RR) and surface enhanced Raman spectroscopy (SERS). UV-VIS allowed observing changes related to the photodegradation process, as a drop in intensity of the absorption band of the chromophoric group. RR and SERS techniques results presented the formation of fluorescent species and changes in the vibrational spectral profile. The photolysis of the dye didn’t occur under any of the sources of irradiation used. AgNPs didn’t promote the photodegradation of the RB5, but nanoparticles of ZnO degraded about 66% of the dye molecules, under the visible radiation (incandescent lamp). Plasmonics photocatalysts Ag∕ZnO were used in the processes of degradation of the RB5 using both sources of irradiation in the visible range, but it was added to the dye solution in different ways. When used directly in suspension and under fluorescent lamp irradiation the photodegradation percentage was 97%. With the addition of the catalyst in the solid state to the dye solution and under fluorescent lamp irradiation 72% of the RB5 molecules were degraded. This last result can be compared to that achieved using ZnO as catalyst and shows a 22% gain in catalytic efficiency under visible light in the presence of the plasmonic material AgNP/ZnO.