Phases organiques luminescentes qui sont incorporés dans une matrice inorganique conductrice est proposé dans cette étude pour la couche active d'une diode émettant de la lumière hybride. Dans ce composite, le colorant organique joue le rôle de site de recombinaison radiative de porteurs de charge qui sont injectées dans la matrice de transport ambipolaire inorganique. Comme l'un des combinaisons de matériaux de candidat, bicouche et des films minces composites de ZnSe et un complexe d'iridium rouge (Ir(BPA)) émetteur de lumière organique ont été préparé in situ par UHV technique d'évaporation thermique. Les alignements de bande d'énergie mesurée par spectroscopie de photoélectrons (PES) pour le ZnSe/Ir(BPA)et deux couches de ZnSe+Ir(BPA) révèlent que le composite HOMO et LUMO du colorant organique sont positionnées dans la largeur de bande interdite de ZnSe. Cette gamme offre les forces motrices énergiques nécessaires pour les transferts d'électrons et de trous de ZnSe à Ir(BPA). Par l'interprétation des données du PES,la composition chimique des interfaces ont également été déterminés. Le ZnSe/Ir(BPA) interface est réactive, même si elle est d'une pureté de matériaux de haute.Pendant ce temps, l'Ir (BPA)/ZnSe interface ne présente pas la pureté matériel. Ceci est représenté à la nature de ZnSe évaporation comme Zn particuliers et des fluxSE2, associée à des interactions chimiques avec le Ir(BPA) substrat. L'interface est,de ce fait, composé d'une multitude de phases, les phases de Se0, ZnSe rares, réduit Se et oxydé molécules de colorant, et de Zn qui sont intercalées atomes dans leIr(BPA) substrat. PES des composites ZnSe+Ir(BPA) révèle des tendances similaires à l'Ir(BPA)/ZnSe interface. A des émissions de lumière rouge surfaciques et intermittents fanées ont été observés à partir de dispositifs qui incorporent couches alternées séquences de ZnSe et Ir(BPA) pour la couche active. / Luminescent organic phases that are embedded in a conductive inorganicmatrix is proposed in this study for the active layer of a hybrid light-emitting diode. Inthis composite, the organic dye acts as the radiative recombination site for chargecarriers that are injected into the inorganic ambipolar transporting matrix. As one ofthe candidate material combinations, bilayer and composite thin films of ZnSe and ared iridium complex (Ir(BPA)) organic light emitter were prepared in situ via UHVthermal evaporation technique. The energy band alignments measured byphotoelectron spectroscopy (PES) for the ZnSe/Ir(BPA) bilayer and ZnSe+Ir(BPA)composite reveal that the HOMO and LUMO of the organic dye are positioned in theZnSe bandgap. This lineup provides the required energetic driving forces for electronand hole transfers from ZnSe to Ir(BPA). By interpreting PES data, the chemicalcomposition of the interfaces were also determined. The ZnSe/Ir(BPA) interface isreactive even though it is of high material purity. Meanwhile, the Ir(BPA)/ZnSeinterface does not exhibit material purity. This is accounted to the nature of ZnSeevaporation as individual Zn and Se2 fluxes, coupled with chemical interactions withthe Ir(BPA) substrate. The interface is, thereby, composed of an abundance of Se0phases, sparse ZnSe phases, reduced Se and oxidized dye molecules, and Znatoms that are intercalated into the Ir(BPA) substrate. PES of the ZnSe+Ir(BPA)composites reveals similar trends to the Ir(BPA)/ZnSe interface. A faded areal andintermittent red light emissions were observed from devices that incorporatedalternating layer sequences of ZnSe and Ir(BPA) for the active layer.

Optofluidics is a new branch within photonics which attempts to unify concepts from optics and microfluidics. Unification of photonics and microfluidics enable us to carry out analysis of fluids through highly sensitive optical sensing device. These optical sensing devices are contained within a microchip, wherein light is made to pass through analyte (fluids of few nanoliters). The interaction between light and fluid gives rise to highly sensitive diagnostic systems. In this work the fabrication and performance characterization of a fluorescent green OLED for optofluidic applications is presented. The effect of thickness variation of hole injection (CuPc) and hole blocking (BCP) layers on the performance of fluorescent green organic light emitting diodes (OLEDs) have been studied. Even though these two organic layers have opposite functions, yet there is a particular combination of their thicknesses when they function in conjunction and luminous efficiency and power efficiency are maximized. The optimum thickness of CuPc layer, used as hole injection layer and BCP used as hole blocking layer were found to be 18 nm and 10 nm respectively. It is with this delicate adjustment of thicknesses, charge balancing was achieved and luminous efficiency and power efficiency were optimized. Such OLEDs with higher luminance can be monolithically integrated with other optical and fluidic components on a common substrate and can function as monolithically integrated internal source of light in optofluidic sensors. In this work the analysis of a fully integrated optofluidic lab-on-a-chip sensor for refractive index and absorbance based sensing using fluorescent green organic light emitting diode (OLED) as a light source is also presented. This device consists of collinear input and output waveguides which are separated by a microfluidic channel. When light is passed through the analyte contained in the fluidic gap an optical power loss due to absorption of light takes place. Apart from absorption a mode-mismatch between collinear input and output waveguide also occurs. The degree of mode-mismatch, quantum of optical power loss due to absorption of light by the fluid forms the basis of our analysis. Detection of minutest change in refractive index and changes in concentration of species contained in the analyte is indicative of sensitivity. Various parameters which influence the sensitivity of the sensor are mode spot size, refractive index of the fluid, molar concentration of the species contained in the analyte, width of the fluidic gap, waveguide geometry. By correlating various parameters, an optimal fluidic gap distance corresponding to a particular mode spot size to achieve the best sensitivity for refractive index based sensing and absorbance based sensing have been determined.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-07-20T20:03:38Z No. of bitstreams: 1 Ediléa Monteiro de Oliveira.pdf: 896757 bytes, checksum: 8bbece5b716734756bc80dba68d50aa2 (MD5) / Made available in DSpace on 2018-07-20T20:03:38Z (GMT). No. of bitstreams: 1 Ediléa Monteiro de Oliveira.pdf: 896757 bytes, checksum: 8bbece5b716734756bc80dba68d50aa2 (MD5) Previous issue date: 2018-03-09 / OBJECTIVE: To evaluate the effects of Photobiomodulation Therapy (PBMT) applied immediately before resistance training in type 2 diabetic women. METHODS: Study 1 consisted of a systematic review registered in PROSPERO (CRD42017060857), with controlled and randomized studies based on PRISMA, in which databases such as LILACS, IBECS, Pubmed / MEDLINE, Cochrane Library, SciELO, PEDro, ScienceDirect and Bireme were consulted, combining the descriptors diabetes mellitus type 2 (T2DM), resistance training, aerobic exercise and oxidative stress in Portuguese, English and Spanish. The methodological quality of the articles was evaluated by the PEDro scale. Data were read, analyzed, extracted and synthesized. Study 2 consisted of a clinical, controlled, randomized, double-blind trial. 32 volunteers were selected between 60 and 75 years old, with a diagnosis of T2DM, following the pre-established inclusion / exclusion criteria. The quadriceps muscle strength was verified by the test of 10 maximal repetitions, the distance walked on the 6MWT and the oxidative metabolism through TBARs and TEAC. The volunteers were randomized into LED group (LTG) and placebo group (TG). The final sample consisted of 26 volunteers, being LTG (n = 13) and TG (n = 13). The intervention consisted of the 30 J PMBT and irradiation of 3 min and 48 s per area in the quadriceps of the dominant lower limb, immediately before the resistance training, for 8 weeks, 2 times a week, on non-consecutive days. The exercises were performed in 2 sets of 8 to 12 repetitions, with 1 to 2 minutes of interval between sets and exercises. All variables were collected pre and post resistance training. The data were analyzed by the GraphPad Prism 5 software and considered statistically significant p <0.05. RESULTS: In study 1 of a total of 746 articles, only 4 met the inclusion criteria. The synthesis of the four selected articles was done, which consisted of randomized controlled clinical trials, that were classified as having a high methodological quality according to an evaluation performed by PEDro Scale, as they obtained a score 6, in a scale from 0 to 10. It was submitted to the Brazilian Journal of Sports Medicine. In the study 2 for muscle strength in the pre and post-intervention LED group (26 ± 9.66 kg, 42.50 ± 7.90 kg, p <0.0001), for the pro-oxidant activity (TBARs) in the pre-LED group and post-intervention (3.76 ± 0.85 mg / ml, 2.52 ± 0.76 mg / ml, p <0.0001) and for antioxidant activity (TEAC) in the pre and post intervention LED group (1, 66 ± 0.13 μmol / L, 2.17 ± 0.23 μmol / L, p <0.0001) there was a statistically significant difference. Only the distance covered in the 6MWT did not present a statistically significant difference. CONCLUSION: For study 1, aerobic physical training seems to be the most effective in reducing glycemic levels and oxidative stress in sedentary individuals with T2DM. For study 2 there was improvement of muscle strength and oxidative metabolism of the group of elderly diabetic type 2 who underwent photobiomodulation therapy applied immediately before the resistance training. / OBJETIVO: Avaliar os efeitos da terapia por fotobiomodulação (TFBM) aplicado imediatamente antes do treinamento resistido em idosas diabéticas do tipo 2. MÉTODOS: O estudo 1 consistiu em uma revisão sistemática registrada no PROSPERO (CRD42017060857), com estudos controlados e randomizados, baseado no PRISMA, no qual foram utilizadas as bases de dados LILACS, IBECS, Pubmed/MEDLINE, Cochrane Library, SciELO, PEDro, ScienceDirect e Bireme sendo pesquisadas pela combinação dos descritores diabetes mellitus tipo 2 (DM2), treinamento de resistência, exercício aeróbio e estresse oxidativo em português, inglês e espanhol. A qualidade metodológica dos artigos foi avaliada pela escala PEDro. Procedeu-se a leitura, análise, extração e síntese dos dados. O estudo 2 consistiu em um ensaio clínico, controlado, randomizado e duplo-cego. 32 voluntárias foram selecionadas entre 60 e 75 anos, com diagnóstico de diabetes mellitus tipo 2, seguindo os critérios de inclusão/exclusão pré-estabelecidos. Foram verificadas a força muscular de quadríceps pelo teste de 10 repetições máximas, a distância percorrida por meio do TC6 e o metabolismo oxidativo por meio do TBARs e TEAC. As voluntárias foram aleatorizadas em grupo LED (GLT) e grupo placebo (GT). A casuística final consistiu em 26 voluntárias, sendo GLT (n=13) e GT (n=13). A intervenção consistiu na TFBM com a dose de 30 J e irradiação de 3 min e 48 s por área, no quadríceps do membro inferior dominante, imediatamente antes do treinamento resistido, durante 8 semanas, 2 vezes por semana, em dias não consecutivos. Os exercícios foram realizados em 2 séries de 8 a 12 repetições, com 1 a 2 minutos de intervalo entre séries e exercícios. Todas variáveis foram coletadas em situação de pré e pós treinamento resistido. Os dados foram analisadas pelo software GraphPad Prism 5 e considerado estisticamente significante p <0,05. RESULTADOS: No estudo 1 de um total de 746 artigos, apenas 4 atenderam aos critérios de inclusão. Foi realizada a síntese dos 4 artigos selecionados, que consistem em ensaios clínicos controlados e randomizados que foram classificados como de alta qualidade metodológica de acordo com avaliação realizada pela Escala PEDro, pois obtiveram como resultado a nota 6, em uma graduação de 0 a 10. Foi submetido à Brazilian Journal of Sports Medicine. No estudo 2 para a força muscular no grupo LED pré e pós-intervenção (26±9,66 Kg; 42,50±7,90 Kg; p<0.0001), para a atividade pró-oxidante (TBARs) no grupo LED pré e pós-intervenção (3,76±0,85 mg/ml; 2,52±0,76 mg/ml; p<0.0001) e para a atividade antioxidante (TEAC) no grupo LED pré e pós-intervenção (1,66±0,13 µmol/L; 2,17±0,23 µmol/L; p<0.0001) houve diferença estatisticamente significante. Somente a distância percorrida no TC6 não apresentou diferença estatisticamente significante. CONCLUSÃO: Para o estudo 1 o treinamento físico aeróbio parece ser o mais eficaz na diminuição dos níveis glicêmicos e do estresse oxidativo nos indivíduos sedentários com DM2. Para o estudo 2 houve melhora da força muscular e do metabolismo oxidativo do grupo de idosas diabéticas tipo 2 que foi submetida à terapia por fotobiomodulação aplicado imediatamente antes do treinamento resistido.

Examensarbetet är en undersökning avseende implementering av Human Centric Lighting (HCL)- system i hemmamiljö. En litteraturstudie har genomförts om HCL, dess effekter på människan och LED-belysningens påverkan både på människan och miljön. För att få en bra praktisk grund gjordes även ett undersökande besök på Lindeborgsskolan i Malmö som i ett pilotprojekt har installerat HCL-system i ett klassrum. HCL handlar bland annat om att anpassa ljuset till människans varierande behov genom att variera intensitet (Lux) och färgtemperatur (Kelvin). Belysning har stor betydelse för människans välmående där en belysning med onaturlig spektralfördelning och flimmer kan leda till stress, sömnproblem samt att ögonen kan försämras. Ett bra varierande ljus kan däremot öka människans välmående, produktivitet och även ge en positivare inställning. En del forskning visar även på att HCL kan minska risken för årstidsbunden depression. Ett blått, mer intensivt ljus har en uppiggande effekt medan ett rött nerdämpat ljus verkar lugnande. Genom att utsätta kroppen för mycket blått ljus på förmiddagen men inte på eftermiddagen/kvällen gynnas kroppens cirkadiska cykel. Även rött ljus har visat sig ha en uppiggande effekt men påverkar inte den cirkadiska cykeln och kan med fördel användas även på kvällstid om en högre ljusintensitet behövs. Tre separata reglerbara belysningssystem har undersökts: Clas Ohlson WiFi Smart Bulb, IKEA trådfri belysning och Philips Hue White Ambiance. Kravet som ställdes för att belysningen skulle tas med i testet var att den skulle finnas tillgänglig i en relativt vanlig butik. Belysningen har testats både med avseende på ljusegenskaper samt energianvändning. En del av mätningarna utfördes med ett Ulbrichtklot på Clas Ohlsons ljuslaboratorium där färgspektrum, lumenvärde samt mycket annan information om ljuskällan kunde tas fram, samt med en handhållen spektrometer för att se flimmeravgivningen ifrån lampan vid olika inställningar. Energianvändningen undersöktes beträffande förändringar vid variation av färgtemperatur, intensitet och även i de fall som separat reglerutrustning krävdes. De tre belysningssystemen visade sig ha olika fördelar och nackdelar där en till slut valdes ut för att installeras i ett sovrum i utbildningsprojektet Dalarnas Villa. Baserat på ett tidigare gjort ljusschema, i en masteruppsats gjord av en ljusdesigner vid KTH, togs ett nytt ljusschema fram för sovrummet som förändrar ljusets intensitet och färgtemperatur för att främja den cirkadiska cykeln. Då författarna ser att detta är ett viktigt ämne så har varje möjlighet till att visa upp det installerade systemet tagits. Vid samtal med bland annat energirådgivare från Dalarna så har ett stort intresse visats. ” Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity (WHO 1946). Health should be at the centre of all societal planning because social inequalities in health are costly to the society and counteract sustainable development (Malmö stad 2013). It is one of the main conditions for individual development opportunities through education, work, social relationships and participation in the society (UN 1949). Health is a key to the other human rights and also constitutes a separate right (WHO 2008).” Sustainability issues for SSL (R. Karlsson et al. 2016) / This thesis is a study concerning the implementation of Human Centric Lighting (HCL)-systems in the home environment. A literature study has been conducted on light, its effects on humans and the influence of LED lighting on both humans and the environment. To obtain a good practical foundation, an investigative study visit was also made to Lindeborgsskolan in Malmö, which as a pilot project has installed HCL systems in a classroom. HCL is, among other things, about adapting the light to man's varying needs by varying intensity (Lux) and color temperature (Kelvin). Lighting is of great importance to human well-being where lighting with unnatural spectral distribution and flicker can lead to stress, sleep problems and that the eyes can deteriorate. A good variety of light can, on the other hand, increase human well-being, productivity and give a positive attitude. Some research also shows that HCL can reduce the risk of seasonal depression. A blue, more intense light has a wakeup effect, while a red low intensity light feels soothing. By exposing the body to much blue light in the morning but not in the afternoon / evening, the body's circadian cycle benefits. Even red light has been shown to have a stimulating effect but does not affect the circadian cycle and can be used even in the evening if a higher light intensity is needed. Three separate controllable lighting systems have been investigated: “Clas Ohlson Wi-Fi Smart Bulb”, “IKEA trådfri” and “Philips Hue White Ambiance”. The lighting has been tested both in terms of light quality and energy use. The light quality was examined partly with an “Ulbrichtklot” at Clas Ohlson's light laboratory where color spectrum as well as various other information could be obtained, and with a hand-held spectrometer to see the flicker output from the lamp at different settings. The energy consumption was investigated regarding variation of color temperature, intensity and even in cases where separate control equipment was required. The three lighting systems were shown to have different advantages where eventually the Philips Hue Ambience White was selected to be installed in a bedroom in the project villa Dalarnas Villa. Based on a previous master thesis, a light schedule was developed that changes the intensity and color temperature of light to promote the circadian cycle. As the authors see this as an important topic, every opportunity to show the installed system has been taken. A great deal of interest has been shown during discussions including Dalarna´s energy advisers. ” Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity (WHO 1946). Health should be at the centre of all societal planning because social inequalities in health are costly to the society and counteract sustainable development (Malmö stad 2013). It is one of the main conditions for individual development opportunities through education, work, social relationships and participation in the society (UN 1949). Health is a key to the other human rights and also constitutes a separate right (WHO 2008).” Sustainability issues for SSL (R. Karlsson et al. 2016)

A numerical model and results for the quantitative simulation of multilayer organic light emitting diode (OLED) and organic solar cell (OSC) are presented. In the model, effects like bipolar charge carrier drift and diffusion with field-dependent mobilities, trapping, dopants, indirect and direct bimolecular recombination, singlet Frenkel exciton diffusion, normal decay and quenching effects are taken into account. For an adequate description of multilayer devices with energetic barriers at interfaces between two adjacent organic layers, thermally assisted charge carrier hopping through the interface, interface recombination, and formation of interface charge transfer (CT) states have been introduced in the model. For the simulation of OSC, the generation of carrier pairs in the mixed layer or at the interface is additionally implemented. The light absorption profile is calculated from optical simulations and used as an input for the electrical simulation. The model is based on three elements: the Poisson equation, the rate equations for charge carriers and the rate equations for singlet Frenkel excitons. These equations are simultaeously solved by spatial and temporal discretisation using the appropriate boundary conditions and electrical parameters. The solution is found when a steady state is reached, as indicated by a constant value of current density. The simulation provides a detailed look into the distribution of electric field and concentration of free and trapped carriers at a particular applied voltage. For organic light emitting diodes, the numerical model helps to analyze the problems of different structures and provides deeper insight into the relevant physical mechanisms involved in device operation. Moreover, it is possible to identify technological problems for certain sets of devices. For instance, we could show that ? in contrast to literature reports - the contact between Alq3 and LiF/Al did not show ohmic behaviour for the series of devices. The role of an additional organic blocking layer between HTL and EML was presented. The explanation for the higher creation efficiency for singlet excitons in the three-layer structure is found in the separation of free holes and electrons accumulating close to the internal interface 1-Naphdata/Alq3. The numerical calculation has demonstrated the importance of controlled doping of the organic materials, which is a way to obtain efficient light emitting diodes with low operating voltage. The experimental results has been reproduced by numerical simulation for a series of OLEDs with different thicknesses of the hole transport layer and emitting layer and for doped emitting layers. The advantages and drawbacks of solar cells based on flat heterojunctions and bulk heterojunctions are analyzed. From the simulations, it can be understood why bulk-heterojunctions typically yield higher photocurrents while flat heterojunctions typically feature higher fill factors. In p-i-n ?structures, p and n are doped wide gap materials and i is a photoactive donor-acceptor blend layer using, e.g,. zinc phthalocyanine as a donor and C60 as an acceptor component. It is found that by introducing trap states, the simulation is able to reproduce the linear dependence of short circuit currents on the light intensity. The apparent light-induced shunt resistance often observed in organic solar cells can also be explained by losses due to trapping and indirect recombination of photogenerated carriers, which we consider a crucial point of our work. However, these two effects, the linear scaling of the photocurrent with light intensity and the apparent photoshunt, could also be reproduced when field-dependent geminate recombination is assumed to play a dominant role. First results that show a temperature independent short circuit photocurrent favour the model based on trap-mediated indirect recombination.

[ES] Las comunicaciones ópticas inalámbricas (OWC) constituyen una tecnología muy prometedora para el desarrollo de futuras comunicaciones inalámbricas. De hecho, ha despertado un interés creciente entre los investigadores y varias empresas de todo el mundo trabajan actualmente en el desarrollo de redes inalámbricas de muy alta velocidad. Las comunidades científica e industrial consideran la OWC como una tecnología complementaria en sus diversas formas: comunicaciones ópticas en el espacio libre (FSO), comunicaciones de luz visible (VLC) o fidelidad de la luz (Li-Fi). El espectro óptico ha sido considerado durante muchos años como una gran oportunidad para las comunicaciones inalámbricas, especialmente debido a la saturación del espectro de radiofrecuencia (RF). Esta disertación trata del uso de fuentes de banda ancha en sistemas de transmisión de luz visible (VLC), así como en sistemas de transmisión en el espectro infrarrojo por fibra óptica. En el trabajo de investigación realizado se pueden distinguir tres partes: En la primera parte, se considera el estudio y la simulación de componentes de Diodos Emisores de Luz (LED) con el software WIEN2k centrándose en las propiedades ópticas y eléctricas de los elementos II-VI. La segunda parte trata del diseño, la implementación y las pruebas de diferentes prototipos de comunicación VLC para la transmisión analógica y digital en modo simplex y semidúplex. Hemos demostrado un sistema OWC empleando una fuente de banda ancha (LED) para la transmisión no sólo de datos, sino también para la transmisión inalámbrica de energía. Además, se aborda el problema de la sincronización y la detección del nivel "1" o "0" de un bit en los sistemas de comunicación inalámbrica óptica implementados que surge como consecuencia de la atenuación de la luz a lo largo de la distancia y al problema de la pérdida de línea de visión (NLOS) entre el emisor y el receptor. Para hacer frente a este problema, se ha proporcionado un protocolo de comunicación que garantiza la transmisión fiable de datos digitales con un algoritmo de detección de nivel de bits adaptativo y se ha demostrado su eficacia mediante la transmisión de textos e imágenes. Además, esta tesis aporta una solución para la implementación de transmisores multiplexados en redes con división de longitud de onda (WDM) para formatos de modulación con multiplexación por división de frecuencia ortogonal (OFDM) basados en el uso de fuentes de banda ancha en el espectro infrarrojo para redes de fibra bidireccionales centralizadas. A pesar de las limitaciones impuestas por la dispersión cromática en el uso de este tipo de fuentes ópticas, la inclusión de ciertas estructuras antes de la detección permite la transmisión de señales OFDM en enlaces ópticos. En este trabajo se ha demostrado experimentalmente la reutilización de portadoras, la asignación dinámica de ancho de banda y la transmisión de señales OFDM multibanda mediante el uso de fuentes ópticas de banda ancha en redes WDM. Los principales resultados obtenidos en cada parte de esta tesis doctoral muestran los procedimientos de estudio, la eficacia de las soluciones propuestas y las limitaciones encontradas. / [CA] Les comunicacions òptiques sense fils (OWC) constitueixen una tecnologia molt prometedora per al desenvolupament de futures comunicacions sense fils. De fet, ha despertat un interés creixent entre els investigadors i diverses empreses de tot el món treballen actualment en el desenvolupament de xarxes sense fils de molt alta velocitat. Les comunitats científica i industrial consideren la OWC com una tecnologia complementària en les seues diverses formes: comunicacions òptiques en l'espai lliure (FSO), comunicacions de llum visible (VLC) o fidelitat de la llum (Li-Fi). L'espectre òptic ha sigut considerat durant molts anys com una gran oportunitat per a les comunicacions sense fils, especialment a causa de la saturació de l'espectre de radiofreqüència (RF). Aquesta dissertació tracta de l'ús de fonts de banda ampla en sistemes de transmissió de llum visible (VLC), així com en sistemes de transmissió en l'espectre infraroig per fibra òptica. En el treball de recerca realitzat es poden distingir tres parts: ¿ En la primera part, es considera l'estudi i la simulació de components de Díodes Emissors de Llum (LED) amb el software WIEN2k centrant-se en les propietats òptiques i elèctriques dels elements II-VI. ¿ La segona part tracta del disseny, la implementació i les proves de diferents prototips de comunicació VLC per a la transmissió analògica i digital de manera simplex i semidúplex. Hem demostrat un sistema OWC emprant una font de banda ampla (LED) per a la transmissió no sols de dades, sinó també per a la transmissió sense fil d'energia. A més, s'aborda el problema de la sincronització i la detecció del nivell "1" o "0" d'un bit en els sistemes de comunicació sense fil òptica implementats, que sorgeix a conseqüència de l'atenuació de la llum al llarg de la distància i al problema de la pèrdua de línia de visió (NLOS) entre l'emissor i el receptor. Per a fer front a aquest problema, s'ha proporcionat un protocol de comunicació que garanteix la transmissió fiable de dades digitals amb un algorisme de detecció de nivell de bits adaptatiu i s'ha demostrat la seua eficàcia mitjançant la transmissió de textos i imatges. ¿ A més, aquesta tesi aporta una solució per a la implementació de transmissors multiplexats en xarxes amb divisió de longitud d'ona (WDM) per a formats de modulació amb multiplexació per divisió de freqüència ortogonal (OFDM) basats en l'ús de fonts de banda ampla en l'espectre infraroig per a xarxes de fibra bidireccionals centralitzades. Malgrat les limitacions imposades per la dispersió cromàtica en l'ús d'aquest tipus de fonts òptiques, la inclusió d'unes certes estructures abans de la detecció permet la transmissió de senyals OFDM en enllaços òptics. En aquest treball s'ha demostrat experimentalment la reutilització de portadores, l'assignació dinàmica d'amplada de banda i la transmissió de senyals OFDM multibanda mitjançant l'ús de fonts òptiques de banda ampla en xarxes WDM. Els principals resultats obtinguts en cada part d'aquesta tesi doctoral mostren els procediments d'estudi, l'eficàcia de les solucions proposades i les limitacions trobades. / [EN] Optical wireless communication (OWC) is a very promising technology for future wireless communications developments. It has attracted increasing interest from researchers and several companies around the world are currently working on the development of very high-speed wireless networks. The scientific and industrial communities believe that OWC will be a complementary technology in its various forms: Free Space Optical communications (FSO), Visible Light Communications (VLC), Light Fidelity (Li-Fi). In fact, the optical spectrum has been considered for many years as a great opportunity for wireless communications especially due to the saturation of the radio frequency (RF) spectrum. This dissertation deals with the use of broadband sources in visible light transmission systems (VLC) as well as fiber optic systems. To carry out the research, three parts can be distinguished: In the first part, we consider the study and simulation of Light Emitting Diode (LED) components with the WIEN2k software by focusing on the optical and electrical properties of elements II-VI. The second part deals with the design, implementation and testing of different VLC communication prototypes for analog and digital transmission in simplex and half-duplex mode. We have demonstrated that an OWC system using a broadband source (i.e. an LED) can be used not only for data transmission, but also for wireless power transmission. Moreover, the synchronization problem and the detection of level "1" or "0" of a bit often arise in the optical wireless communication systems. This is a result of the attenuation nature of the light over the distance and the problem of Non Line-Of-Sight (NLOS) between the emitter and the receiver. To deal with this problem, a communication protocol ensuring reliable digital data transmission with an adaptive bit level detection algorithm has been provided and its effectiveness has been demonstrated by the transmission of texts and images. In addition, this thesis provides a solution for the implementation of wavelength division multiplexed - orthogonal frequency division multiplexed (WDM-OFDM) transmitters based on the use of broadband sources in the infrared spectrum for centralized bidirectional fiber networks. Despite the chromatic dispersion that avoids the use of this type of optical sources, the inclusion of certain structures before detection allows the transmission of OFDM signals in optical links. Carrier reuse, dynamic bandwidth allocation and multiband OFDM signals transmission will be experimentally demonstrated by using optical broadband sources in WDM networks. The main results obtained during this thesis work demonstrate the study procedures, for each part, the effectiveness of the proposed solutions as well as the constraints encountered. / Sekkiou, I. (2021). Design of communication systems based on broadband sources for fiber and free space optical links [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172542 / TESIS

In this thesis I present a study of nanowires, and, in particular, I apply EBIC microscopy for investigation of their electro-optical properties. First, I describe details of the EBIC analytical technique together with a brief historical overview of the electron microscopy, the physical principles of the EBIC, its space resolution, parameters defining the signal amplitude, and the information we can acquire concerning defects, electric fields, etc. Then I focus on the characterization of LEDs based on GaN nanowires, which were analyzed in a cross-section and in a top view configurations. The EBIC measurements were correlated with micro-electroluminescence mapping. Further, I address the fabrication and measurement of nanowire-based InGaN/GaN LEDs detached from their original substrate. I present the EBIC measurements of individual nanowires either cut from their substrate and contacted in a planar geometry or kept standing on supphire substrate and cleaved to reveal the horizontal cross-section.The next part of this thesis is dedicated to an EBIC study of irregular Si nanowire array-based solar cells, and then of the regular nanowire array devices. The current generation was analyzed on a submicrometer scale. Finally, I discuss the fabrication and EBIC measurements of GaN nanowires grown on Si substrate. In particular, I show that the p-n junction was induced in the Si substrate by Al atom diffusion during the nanowire growth. / Dans cette thèse je me propose d’étudier des nano-fils, et en particulier d’utiliser la technique EBIC pour explorer leurs propriétés électro-optiques. Je décris d’abord les détails de la technique d’analyse EBIC avec un bref retour historique sur la microscopie électronique, le principe physique de l’EBIC, sa résolution spatiale, les paramètres conditionnant l’amplitude du signal, et les informations que l’on peut en tirer sur le matériau en termes de défauts, champ électrique, etc. Je m’intéresse ensuite à la caractérisation de LEDs à nano-fils à base de GaN, qui ont été observés par EBIC, soit en coupe soit en vue plane (depuis le haut des fils). Les mesures EBIC sont comparées à celles de micro-électroluminescence. Plus loin j’adresse la fabrication et la mesure de nano-fils à base de GaN séparés de leur substrat d’origine. Je présente les mesures EBIC de nano-fils uniques entiers, puis de nano-fils en coupe horizontale.La partie suivante de la thèse traite d’étude EBIC des cellules solaires à base de nano-fils Si ayant d’abord une géométrie aléatoire, puis une géométrie régulière. La génération de courant dans ces cellules solaires est analysée à l’échelle submicronique. A la fin du manuscrit je discute la fabrication et les mesures EBIC de fils GaN épitaxiés sur Si. Je montre en particulier qu’une jonction p-n est enduite dans le substrat Si par la diffusion d’Al lors de la croissance de nanofils.

A novel, non-volatile, organic capacitive memory device called p-i-n-metal-oxide-semiconductor (pinMOS) memory is demonstrated with multiple-bit storage that can be programmed and read out electrically and optically. The diode-based architecture simplifies the fabrication process, and makes further optimizations easy, and might even inspire new derived capacitive memory devices. Furthermore, this innovative pinMOS memory device features local charge up of an integrated capacitance rather than of an extra floating gate. Before the device can perform as desired, the leakage current due to the lateral charge up of the doped layers outside the active area needs to be suppressed. Therefore, in this thesis, lateral charging effects in organic light-emitting diodes (OLEDs) are studied first. By comparing the results from differently structured devices, the presence of centimeter-scale lateral current flows in the n-doped and p-doped layers is shown, which results in undesirable capacitance increases and thus extra leakage currents. Such lateral charging can be controlled via structuring the doped layers, leading to extremely low steady-state leakage currents in the OLED (here 10-7 mA/cm2 at -1 V). It is shown that these lateral currents can be utilized to extract the conductivity as well as the activation energy of each doped layer when modeled with an RC circuit model. Secondly, pinMOS memory devices that are based on the diode with structured doped layers are investigated. The memory behavior, which is demonstrated as capacitance switching for electrical signals, and light emission for optical signals, can be tuned either by the applied voltage or ultraviolet light illumination, respectively. The working mechanism is explained by the existence of quasi steady-states as well as the width variation of space charge zones. The pinMOS memory shows excellent repeatability, an endurance of more than 104 write-read-erase-read cycles, and currently already over 24 h retention time. Furthermore, an early-stage investigation on emulating synaptic plasticity reveals the potential of pinMOS memory for applications in neuromorphic computing. Overall, the results indicate that pinMOS memory in principle is promising for a variety of future applications in both electronic and photonic circuits. A detailed understanding of this new concept of memory device, for which this thesis lays an important foundation, is necessary to proceed with further enhancements.:1 Introduction 1 2 Fundamentals of organic semiconductors 5 2.1 Electronic states of a molecule 5 2.1.1 Atomic orbitals and molecular orbitals 5 2.1.2 Solid states 9 2.1.3 Singlet and triplet states 12 2.2 Charge transport 13 2.2.1 Charge carrier mobility 13 2.2.2 Charge carrier transport 14 2.3 Charge injection 17 2.3.1 Current limitation 17 2.3.2 Charge injection mechanisms 20 2.4 Doping 22 3 Organic junctions and devices 25 3.1 Metal-semiconductor junction 25 3.1.1 Schottky junction 25 3.1.2 Surface states 27 3.2 Metal-oxide-semiconductor capacitor 29 3.3 Junctions and diodes 31 3.3.1 PN junction and diode 31 3.3.2 PIN junction and diode 32 4 Organic non-volatile memory devices 35 4.1 Basic concepts 35 4.2 Organic resistive memory devices 37 4.2.1 Device architecture and switching behavior 38 4.2.2 Working mechanisms 38 4.3 Organic transistor-based memory devices 41 4.3.1 Organic field-effect transistor and memory devices based thereon 41 4.3.2 Floating gate memory 43 4.3.3 Charge trapping memory 45 4.4 Organic ferroelectric memory devices 46 4.4.1 Ferroelectric capacitor memory 47 4.4.2 Ferroelectric transistor memory 48 4.4.3 Ferroelectric diode memory 49 5 Experimental methods 53 5.1 Device fabrication 53 5.2 Device characterization 55 5.3 Materials 57 6 Lateral current flow in semiconductor devices having crossbar electrodes 61 6.1 Introduction 61 6.2 Device architecture 62 6.3 Characteristics comparison between unstructured and structured devices 63 6.3.1 Charging measurement 63 6.3.2 Current-voltage characteristics 64 6.3.3 Capacitance-frequency characteristics 67 6.4 Influence of conductivity of doped layers 69 6.4.1 Dependence on doped layers thickness 69 6.4.2 Dependence on temperature 73 6.5 Lateral charging simulation 74 6.5.1 Analytical description 74 6.5.2 RC circuit simulation 76 6.5.3 Parameters for doped layers gained by simulation 79 6.6 Pseudo trap analysis 81 6.6.1 The pseudo trap density of states determination 81 6.6.2 The pseudo trap analysis under simulated identical conditions 84 6.7 Summary 85 7 The pinMOS memory: novel diode-capacitor memory with multiple-bit storage 87 7.1 Introduction 87 7.2 Device architecture 88 7.2.1 Dependence on layout and pixel 89 7.2.2 Fundamental memory behavior characterization 93 7.3 Working mechanism 96 7.3.1 Working mechanism of quasi-steady states 97 7.3.2 Working mechanism of dynamic states 101 7.4 Tunability of the memory effect 105 7.4.1 Operation parameters 106 7.4.2 Photoinduced tunability 108 7.4.3 Intrinsic layer thickness 110 7.5 Potential in neuromorphic computing application 111 7.5.1 Extracting capacitance at 0 V sequentially 112 7.5.2 Mimicking the long-term plasticity (LTP) behavior 113 7.6 Summary 114 8 Optoelectronic properties of pinMOS memory 117 8.1 Introduction 117 8.2 Measurement setup 117 8.3 pinMOS memory emission intensity 118 8.4 Pulse characteristics and device brightness 119 8.5 Conclusion 124 9 Conclusion 125 Bibliography 129 List of Figures 145 List of Tables 151 List of Abbreviations 153 Publications and Conference 157 Acknowledgment 159 / Es wird ein neuartiges, organisches kapazitives Speicherelement demonstriert, das p-i-n-Metalloxid-Halbleiter (pinMOS) Speicher genannt wird und eine Mehrfachbitspeicherung besitzt, die elektrisch und optisch programmiert und ausgelesen werden kann. Die auf einer Diode basierende Architektur vereinfacht den Herstellungsprozess sowie die weitere Optimierung und könnte sogar Inspiration für neue kapazitive Speichermedien sein. Darüber hinaus basiert dieses innovative pinMOS Speicherelement auf der lokalen Aufladung einer integrierten Kapazität und nicht auf einem zusätzlichem “Floating Gate”. Bevor das Speicherelement wie gewünscht funktioniert, muss der Leckstrom, der durch die laterale Aufladung der dotierten Schichten außerhalb des aktiven Bereichs verursacht wird, unterdrückt werden. Deshalb werden in dieser Arbeit zuerst die lateralen Aufladungseffekte in organischen Leuchtdioden (OLEDs) untersucht. Beim Vergleich verschiedener Device-Strukturen wird die Existenz von lateralen Stromflüssen im Zentimeterbereich in den n- und p-dotierten Schichten gezeigt, was zu einer unerwünschten erhöhten Kapazität und folglich einem höheren Leckstrom führt. Diese laterale Aufladung kann durch die Strukturierung der dotierten Schichten kontrolliert werden, was zu extrem geringen Gleichgewichtsleckströmen in den OLEDs (10-7 mA/cm2 bei -1 V) resultiert. Es wird auch gezeigt, dass die lateralen Ströme genutzt werden können um die spezifische Leitfähigkeit sowie die Aktivierungsenergie der einzelnen dotierten Schichten zu extrahieren, wenn diese mit einem RC-Modell modelliert werden. Im zweiten Teil werden pinMOS Speicherelemente, die auf der Diode mit strukturierten dotierten Schichten basieren, untersucht. Das Speicherverhalten, dass durch Kapazitätsschaltung für elektrische Signale und als Lichtemission für optische Signale gezeigt wird, kann entweder durch die angelegte Spannung, beziehungsweise durch die Belichtung mit ultraviolettem Licht eingestellt werden. Die Wirkungsweise wird durch die Existenz quasistatischer Gleichgewichte sowie durch die Größenänderung der Raumladungszonen erklärt. Der pinMOS Speicher zeigt eine hervorragende Wiederholbarkeit, eine Beständigkeit über mehr als 104 Schreiben-Lesen-Löschen-Lesen Zyklen und aktuell schon eine Retentionszeit von über 24 h. Weiterhin offenbaren erste Versuche in der Nachahmung von Neuronaler Plastizität das Potenzial von pinMOS Speichern für Anwendungen im “Neuromorphic Computing”. Insgesamt deuten die Ergebnisse an, dass pinMOS Speicher prinzipiell vielversprechend für eine Vielzahl von zukünftigen Anwendungen in elektronischen und photonischen Schaltkreisen ist. Ein tiefgreifendes Verständnis von diesem Konzept neuartiger Speicherelemente, für das diese Arbeit eine wichtige Grundlage bildet, ist notwendig, um weitere Verbesserungen zu entwickeln.:1 Introduction 1 2 Fundamentals of organic semiconductors 5 2.1 Electronic states of a molecule 5 2.1.1 Atomic orbitals and molecular orbitals 5 2.1.2 Solid states 9 2.1.3 Singlet and triplet states 12 2.2 Charge transport 13 2.2.1 Charge carrier mobility 13 2.2.2 Charge carrier transport 14 2.3 Charge injection 17 2.3.1 Current limitation 17 2.3.2 Charge injection mechanisms 20 2.4 Doping 22 3 Organic junctions and devices 25 3.1 Metal-semiconductor junction 25 3.1.1 Schottky junction 25 3.1.2 Surface states 27 3.2 Metal-oxide-semiconductor capacitor 29 3.3 Junctions and diodes 31 3.3.1 PN junction and diode 31 3.3.2 PIN junction and diode 32 4 Organic non-volatile memory devices 35 4.1 Basic concepts 35 4.2 Organic resistive memory devices 37 4.2.1 Device architecture and switching behavior 38 4.2.2 Working mechanisms 38 4.3 Organic transistor-based memory devices 41 4.3.1 Organic field-effect transistor and memory devices based thereon 41 4.3.2 Floating gate memory 43 4.3.3 Charge trapping memory 45 4.4 Organic ferroelectric memory devices 46 4.4.1 Ferroelectric capacitor memory 47 4.4.2 Ferroelectric transistor memory 48 4.4.3 Ferroelectric diode memory 49 5 Experimental methods 53 5.1 Device fabrication 53 5.2 Device characterization 55 5.3 Materials 57 6 Lateral current flow in semiconductor devices having crossbar electrodes 61 6.1 Introduction 61 6.2 Device architecture 62 6.3 Characteristics comparison between unstructured and structured devices 63 6.3.1 Charging measurement 63 6.3.2 Current-voltage characteristics 64 6.3.3 Capacitance-frequency characteristics 67 6.4 Influence of conductivity of doped layers 69 6.4.1 Dependence on doped layers thickness 69 6.4.2 Dependence on temperature 73 6.5 Lateral charging simulation 74 6.5.1 Analytical description 74 6.5.2 RC circuit simulation 76 6.5.3 Parameters for doped layers gained by simulation 79 6.6 Pseudo trap analysis 81 6.6.1 The pseudo trap density of states determination 81 6.6.2 The pseudo trap analysis under simulated identical conditions 84 6.7 Summary 85 7 The pinMOS memory: novel diode-capacitor memory with multiple-bit storage 87 7.1 Introduction 87 7.2 Device architecture 88 7.2.1 Dependence on layout and pixel 89 7.2.2 Fundamental memory behavior characterization 93 7.3 Working mechanism 96 7.3.1 Working mechanism of quasi-steady states 97 7.3.2 Working mechanism of dynamic states 101 7.4 Tunability of the memory effect 105 7.4.1 Operation parameters 106 7.4.2 Photoinduced tunability 108 7.4.3 Intrinsic layer thickness 110 7.5 Potential in neuromorphic computing application 111 7.5.1 Extracting capacitance at 0 V sequentially 112 7.5.2 Mimicking the long-term plasticity (LTP) behavior 113 7.6 Summary 114 8 Optoelectronic properties of pinMOS memory 117 8.1 Introduction 117 8.2 Measurement setup 117 8.3 pinMOS memory emission intensity 118 8.4 Pulse characteristics and device brightness 119 8.5 Conclusion 124 9 Conclusion 125 Bibliography 129 List of Figures 145 List of Tables 151 List of Abbreviations 153 Publications and Conference 157 Acknowledgment 159

Der Schwerpunkt dieser Arbeit liegt auf der Entwicklung von Technologien und Prozessen, welche die Marktakzeptanz organischer Leuchtdioden (OLED) durch Steigerung der Effizienz und Leuchtdichtehomogenität erhöhen. Dazu werden die Fertigungskosten durch neuartige Herstellungsverfahren reduziert und die Realisierung von effizienten, großflächigen (> 300×300 mm2) und homogen leuchtenden OLED-Modulen in beliebiger Modulform ermöglicht. Um dies zu erreichen, wurden folgende drei Ansätze verfolgt: 1. Die Optimierung der Strukturierung dünner Schichten bei Substraten für die organische Elektronik unter Verwendung der Technologien Siebdruck und Laserablation. Es werden neuartige Druckpasten auf ihre Eigenschaften hin untersucht und deren Eignung für die Substratstrukturierung bei OLEDs mittels Testmodulen elektro-optisch charakterisiert. Weiterhin steht die Verringerung der parasitären Leckströme durch einen optimierten Laserablationsprozess zur Grundelektrodenstrukturierung und einer Variation der Dicke der Löchertransportschicht im Fokus. 2. Die Realisierung einer schattenmasken- und photolithografiefreien seriellen elektrischen Verschaltung von mehreren kleinen OLED-Segmenten zu einem großen Gesamtmodul. Dazu werden ein Verfahren für die Erzeugung einer elektrischen Verbindung zwischen Top- und Grundelektrode sowie zwei hochinnovative Verfahren zur Separation einer vollflächig abgeschiedenen Topelektrode entwickelt und auf ihre Eignung hin validiert. 3. Die Verbesserung der Lichtauskopplung aus OLED-Modulen mittels einer modulinternen Streuschicht. Es werden fünf unterschiedliche Streupartikelarten und zwei Matrixmaterialien untersucht und deren Auswirkungen auf die Lichtauskopplung anhand von OLED-Testmodulen charakterisiert. Die entwickelten Verfahren und Prozessen basieren auf den Technologien Siebdruck und Laserablation, sind explizit für die Fertigung flexibler Module auf Basis von Trägermaterialien wie Dünnglas oder Polymerfolien sowie einem Rolle-zu-Rolle-Herstellungsverfahren geeignet und können direkt in eine großserientechnische Herstellung von OLED-Modulen überführt werden. / The focus of this work is upon the development of technologies and processes to increase the efficiency and brightness homogeneity of organic light-emitting diodes (OLEDs) in order to improve their market acceptance. Additionally, manufacturing costs will be reduced by adopting the new processes and it will be shown that the production of efficient, large-area (up to 300 × 300 mm2) and uniformly bright OLED modules of an arbitrary shape is possible. To achieve this, three approaches were followed: 1. The optimization of the structuring of thin layers on substrates for organic electronics using screen printing and laser ablation. To achieve this, the properties of novel printing pastes were determined, and their suitability for structuring substrates was assessed using results from the electro-optical characterization of test modules. Furthermore, the parasitic leakage current was minimized by optimizing the laser ablation process used for the structuring of the bottom electrode, together with the thickness of the hole transport layer. 2. The electrical connection in series of several small OLED segments to make a larger module without the need for shadow masks or photolithographic processes was studied. This included the development of a technique to connect the top and bottom electrodes, as well as two highly innovative methods to produce a completely separated top electrode using structuring by laser ablation. The suitability of these methods for OLED production was confirmed. 3. A scattering layer within the modules was developed to improve the light outcoupling. Five types of scattering particle in two different matrix materials were examined, and the effects of the resulting scattering layer on the outcoupling from an OLED test module were characterized. The newly developed processes make use of screen printing and laser ablation and are thus well suited to the production of flexible OLED modules using support materials such as thin glass or polymer foils with roll-to-roll processing. Accordingly, such technologies could readily be transferred to the large volume production of OLED modules.

Der externe Wirkungsquerschnitt von auf AlGaAs/InGaAlP basierenden Leuchtdioden (LEDs) ist auf Grund von Totalreflexion infolge des hohen Brechungsindex des Halbleitermaterials (n=3...4) beschränkt. Auf die Oberfläche der LED aufgebrachte metallische Nanoteilchen (MNT) können jedoch als Dipolstreuer genutzt werden, um so die Emission der LED zu vergrößern. In dieser Arbeit wurden zunächst einzelne Goldnanoteilchen verschiedener Größe auf einer solchen Leuchtdiode in zwei verschiedenen Der externe Wirkungsquerschnitt von auf AlGaAs/InGaAlP basierenden Leuchtdioden (LEDs) ist auf Grund von Totalreflexion infolge des hohen Brechungsindex des Halbleitermaterials (n=3...4) beschränkt. Auf die Oberfläche der LED aufgebrachte metallische Nanoteilchen (MNT) können jedoch als Dipolstreuer genutzt werden, um so die Emission der LED zu vergrößern. In dieser Arbeit wurden zunächst einzelne Goldnanoteilchen verschiedener Größe auf einer solchen Leuchtdiode in zwei verschiedenen Umgebungsmedien untersucht. Dabei zeigt sich eine deutliche Verstärkung der Emission, falls die Dipolresonanz des MNT bei kürzeren Wellenlängen im Vergleich zur LED-Emission liegt. Für den Fall, dass die Dipolresonanz mit der Emission überlappt oder bei größeren Wellenlängen liegt, kommt es zu einer Abschwächung. Numerische Berechnungen zeigen, dass dabei die Stärke der Quadrupolmode, welche zusätzliche Absorption hervorruft, sowie eine Rotverschiebung der Dipolresonanz bei Anregung oberhalb des kritischen Winkels der Totalreflexion eine entscheidende Rolle spielen. Mit Hilfe einer speziellen Maskentechnik, der Fischer-Pattern-Nanolithographie, können Arrays von MNT hergestellt und anschließend die MNT in Form und Größe manipuliert werden. Die zunächst dreieckige Form der Partikel führt zu einer Abschwächung der Emission, welche sich aber durch Umwandlung der MNT in Kugeln zu einer Emissionsverstärkung wendet. Dabei kann Licht, welches sonst im Substrat gefangen wäre, durch plasmonische Streuung ausgekoppelt werden. Eine Untersuchung ähnlicher Strukturen auf einem hochbrechenden, transparenten Substrat (GaP) zeigt, dass die Lage der plasmonischen Resonanzen stärker vom Abstand der Partikel abhängt, als gewöhnlich zu erwarten wäre.:1 Eigenschaften metallischer Nanoteilchen 2 Untersuchung der Lichtauskopplungsverstärkung einzelner Metalnanoteilchen auf der LED 3 Regelmäßig angeordnete metallische Nanoteilchen - Herstellung und Verstärkungseigenschaften 4 Manipulation der Größe metallischer Nanopartikel 5 Eigenschaften eines Arrays metallischer Nanopartikel auf einem hochbrechenden Substrat 6 Abschlussdiskussion / The external quantum efficiency of light-emitting diodes (LEDs) based on AlGaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called \"Fischer pattern nanolithography\" and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data.:1 Eigenschaften metallischer Nanoteilchen 2 Untersuchung der Lichtauskopplungsverstärkung einzelner Metalnanoteilchen auf der LED 3 Regelmäßig angeordnete metallische Nanoteilchen - Herstellung und Verstärkungseigenschaften 4 Manipulation der Größe metallischer Nanopartikel 5 Eigenschaften eines Arrays metallischer Nanopartikel auf einem hochbrechenden Substrat 6 Abschlussdiskussion