Deeper understanding and technological progress in materials physics demand exploration of soft and hard matter at their relevant length scales. This research focuses on the nanometer length scale investigation of structural changes required for membrane fusion in virus nanoparticles and nano-spectroscopic investigation of layered material surfaces implementing scattering type scanning near-field optical microscopy (s-SNOM). Spectroscopy and imaging experiments were deployed to investigate the chemical and structural modifications of the viral protein and lipid bilayer under various environmental pH variations. It has been shown that breakage of viral membrane could occur even without the presence of a targeting membrane, if the environment pH is lowered. This is in contrary to the current viral fusion model, which requires virus binding to a host cell membrane for forming the fusion pore to release the viral genome. The fusion inhibitor compound 136 can effectively prevent the membrane breakage induced by low pH. The chemical surface stability and degradation of black phosphorus (BP) under ambient conditions have been studied using s-SNOM. We found that the degraded area and volume on the surface of black phosphorus increase with time slowly at the start of degradation and enlarge rapidly (roughly exponentially) afterward and reach saturation growth following S-shaped growth curve (sigmoid growth curve). The theoretical model presented suggests that the degraded sites in the adjacent surrounding causes the experimentally observed exponential growth of degraded area at the initial stage. By studying the BP surfaces coated by Al2O3, boron nitride (BN) and hybrid BN/Al2O3 layers through the period up to 6 months, it has been concluded that ~5 nm thin hybrid layer of BN/Al2O3 helps the surface passivation of BP flakes of thickness ~30 nm. This is supported by the electrical characterization results of BP field effect transistor coated with a BN/Al2O3 layer. We have performed infrared nano-spectroscopy on muscovite mica exfoliated on silicon and silicon dioxide substrates. We show that the near-field profile in s-SNOM can penetrate down to several hundreds of nanometers and enable spectroscopy of buried structures. We found spectral broadening of mica as its thickness increases revealing clearly the effect of size on the absorption response.

Esta Tese de doutorado teve por objetivo aumentar a compreensão dos aspectos sinérgicos na corrosão de bens culturais feitos com chumbo (Pb) e avaliar a agressividade ambiental sobre bens culturais em igrejas e museus brasileiros para a proposição de estratégias de conservação. Neste contexto, foram investigados, em microambientes simulados, os efeitos sinérgicos entre formaldeído e ácido acético, ácido fórmico ou dióxido de carbono na corrosão de Pb; foi feita a síntese e caracterização de diferentes formiatos gerados nos processos de corrosão de Pb por formaldeído ou ácido fórmico; foi avaliada a agressividade ambiental sobre bens culturais da Igreja de São Francisco (São Paulo, ambiente urbano industrial), da Igreja dos Freis Carmelitas (Santos, ambiente urbano industrial costeiro), do Museu de Arte Contemporânea da USP (MAC, São Paulo, reserva técnica da nova sede) e do Museu de Arqueologia e Etnologia da USP (MAE, São Paulo, reserva técnica), através de cupons metálicos (chumbo e cobre) expostos nos ambientes interno e externo dessas instituições e através do uso de monitores miniaturizados; foi feita a otimização destes monitores e, finalmente, foi considerado o desenvolvimento de um nariz eletrônico (EN) baseado em microbalanças de quartzo (QCMs) para o uso em conservação preventiva. Nestas investigações microscopia Raman foi a principal técnica empregada, sendo que as demais foram FTIR-ATR, µ-FTIR-ATR, µ-FTIR, nano-FTIR (SINS), s-SNOM, AFM, SEM, SEM-EDX, XRD e SR-XRD. Os resultados apontaram para a necessidade de individualização dos objetos artísticos tanto para a proposição de estratégias de conservação quanto para o entendimento de sua reatividade, mostraram a agressividade ambiental de todas as instituições investigadas, indicaram a potencialidade de ENs em conservação preventiva e demonstraram a utilidade de técnicas de alta resolução lateral, como nano-FTIR, em investigações de corrosão metálica. Mais especificamente, as investigações de sinergia entre poluentes aumentaram o entendimento da reatividade de Pb e permitiram a proposição de esquemas mais completos de sua reatividade, levando a discussões acerca da conservação desses bens. A agressividade química ambiental das igrejas e museus a bens culturais foi inferida pela caracterização de cupons metálicos expostos em seus interiores e exteriores, enquanto que a agressividade relacionada a fatores físicos, como temperatura e umidade relativa, foi inferida através do uso de monitores miniaturizados expostos somente nas igrejas. Com esse monitoramento, estratégias de conservação foram propostas. Para a devida caracterização dos cupons metálicos, expostos nas igrejas e museus ou nos microambientes simulados, a síntese e a caracterização de diferentes formiatos de Pb foi essencial. Por fim, visando melhorar o desempenho dos monitores miniaturizados e ampliar sua aplicabilidade (com seu futuro uso como EN), um novo dispositivo foi construído e um estágio na Universidade de Aveiro, em Portugal, foi realizado para o desenvolvimento de um EN baseado em QCMs. / The objective of this doctoral thesis was to increase the understanding of synergistic aspects in the corrosion of cultural objects made with lead (Pb) and to assess the environmental aggressiveness on cultural objects of Brazilian churches and museums in order to propose conservation strategies. In this context, in simulated micro-environments, the synergistic effects between formaldehyde and acetic acid, formic acid or carbon dioxide in Pb corrosion were investigated; the syntheses and characterization of different formates generated by formaldehyde or formic acid in Pb corrosion processes was conducted; the environmental aggressiveness on cultural objects of the church of São Francisco (São Paulo, urban industrial environment), of the church of the Carmelite Friars (Santos, urban industrial littoral environment), of the Museum of Contemporary Art of the USP (MAC, São Paulo, new site) and of the Museum of Archaeology and Ethnology of the USP (MAE, São Paulo) was assessed exposing metal coupons (lead and copper) in their internal and external environments and using miniaturized monitors; these monitors were optimized and finally, the development of an \'electronic nose\' (EN) based on quartz crystal microbalances (QCMs) was considered for preventive conservation. In these investigations the principal technique employed was Raman microscopy, and FTIR-ATR, µ-FTIR-ATR, µ-FTIR, nano-FTIR (SINS), s-SNOM, AFM, SEM, SEM-EDX, XRD and SR-XRD were also used. The results pointed out to the necessity of individualization of the artistic objects when investigating their reactivity or when proposing conservation strategies, showed the environmental aggressiveness of all the investigated institutions, indicated the potential of ENs in preventive conservation and demonstrated the utility of techniques of high lateral resolution such as nano-FTIR for the investigation of metal corrosion. More specifically, the investigations of synergistic effects between gaseous pollutants increased the understanding of Pb reactivity and allowed to propose more completed schemes of its reactivity, which allowed discussions on the conservation of these objects. The aggressiveness related to the environmental chemical composition of the churches and museums was inferred through the characterization of metal coupons exposed in their indoor and outdoor environments, whilst the aggressiveness related to physical factors such as temperature and relative humidity was inferred through the use of miniaturized monitors exposed only in the churches. With this monitoring, conservation strategies were proposed. For the well characterization of the metal coupons, exposed in the churches and museums or in simulated microenvironments, the syntheses and characterization of different Pb formates were essential. Finally, aiming at still improving the performance of the miniaturized monitors and increasing their applicability (in their future use as EN), a new device was constructed, and an internship was considered in the University of Aveiro, Portugal, for the development of an EN based on QCMs.

Esta Tese de doutorado teve por objetivo aumentar a compreensão dos aspectos sinérgicos na corrosão de bens culturais feitos com chumbo (Pb) e avaliar a agressividade ambiental sobre bens culturais em igrejas e museus brasileiros para a proposição de estratégias de conservação. Neste contexto, foram investigados, em microambientes simulados, os efeitos sinérgicos entre formaldeído e ácido acético, ácido fórmico ou dióxido de carbono na corrosão de Pb; foi feita a síntese e caracterização de diferentes formiatos gerados nos processos de corrosão de Pb por formaldeído ou ácido fórmico; foi avaliada a agressividade ambiental sobre bens culturais da Igreja de São Francisco (São Paulo, ambiente urbano industrial), da Igreja dos Freis Carmelitas (Santos, ambiente urbano industrial costeiro), do Museu de Arte Contemporânea da USP (MAC, São Paulo, reserva técnica da nova sede) e do Museu de Arqueologia e Etnologia da USP (MAE, São Paulo, reserva técnica), através de cupons metálicos (chumbo e cobre) expostos nos ambientes interno e externo dessas instituições e através do uso de monitores miniaturizados; foi feita a otimização destes monitores e, finalmente, foi considerado o desenvolvimento de um nariz eletrônico (EN) baseado em microbalanças de quartzo (QCMs) para o uso em conservação preventiva. Nestas investigações microscopia Raman foi a principal técnica empregada, sendo que as demais foram FTIR-ATR, µ-FTIR-ATR, µ-FTIR, nano-FTIR (SINS), s-SNOM, AFM, SEM, SEM-EDX, XRD e SR-XRD. Os resultados apontaram para a necessidade de individualização dos objetos artísticos tanto para a proposição de estratégias de conservação quanto para o entendimento de sua reatividade, mostraram a agressividade ambiental de todas as instituições investigadas, indicaram a potencialidade de ENs em conservação preventiva e demonstraram a utilidade de técnicas de alta resolução lateral, como nano-FTIR, em investigações de corrosão metálica. Mais especificamente, as investigações de sinergia entre poluentes aumentaram o entendimento da reatividade de Pb e permitiram a proposição de esquemas mais completos de sua reatividade, levando a discussões acerca da conservação desses bens. A agressividade química ambiental das igrejas e museus a bens culturais foi inferida pela caracterização de cupons metálicos expostos em seus interiores e exteriores, enquanto que a agressividade relacionada a fatores físicos, como temperatura e umidade relativa, foi inferida através do uso de monitores miniaturizados expostos somente nas igrejas. Com esse monitoramento, estratégias de conservação foram propostas. Para a devida caracterização dos cupons metálicos, expostos nas igrejas e museus ou nos microambientes simulados, a síntese e a caracterização de diferentes formiatos de Pb foi essencial. Por fim, visando melhorar o desempenho dos monitores miniaturizados e ampliar sua aplicabilidade (com seu futuro uso como EN), um novo dispositivo foi construído e um estágio na Universidade de Aveiro, em Portugal, foi realizado para o desenvolvimento de um EN baseado em QCMs. / The objective of this doctoral thesis was to increase the understanding of synergistic aspects in the corrosion of cultural objects made with lead (Pb) and to assess the environmental aggressiveness on cultural objects of Brazilian churches and museums in order to propose conservation strategies. In this context, in simulated micro-environments, the synergistic effects between formaldehyde and acetic acid, formic acid or carbon dioxide in Pb corrosion were investigated; the syntheses and characterization of different formates generated by formaldehyde or formic acid in Pb corrosion processes was conducted; the environmental aggressiveness on cultural objects of the church of São Francisco (São Paulo, urban industrial environment), of the church of the Carmelite Friars (Santos, urban industrial littoral environment), of the Museum of Contemporary Art of the USP (MAC, São Paulo, new site) and of the Museum of Archaeology and Ethnology of the USP (MAE, São Paulo) was assessed exposing metal coupons (lead and copper) in their internal and external environments and using miniaturized monitors; these monitors were optimized and finally, the development of an \'electronic nose\' (EN) based on quartz crystal microbalances (QCMs) was considered for preventive conservation. In these investigations the principal technique employed was Raman microscopy, and FTIR-ATR, µ-FTIR-ATR, µ-FTIR, nano-FTIR (SINS), s-SNOM, AFM, SEM, SEM-EDX, XRD and SR-XRD were also used. The results pointed out to the necessity of individualization of the artistic objects when investigating their reactivity or when proposing conservation strategies, showed the environmental aggressiveness of all the investigated institutions, indicated the potential of ENs in preventive conservation and demonstrated the utility of techniques of high lateral resolution such as nano-FTIR for the investigation of metal corrosion. More specifically, the investigations of synergistic effects between gaseous pollutants increased the understanding of Pb reactivity and allowed to propose more completed schemes of its reactivity, which allowed discussions on the conservation of these objects. The aggressiveness related to the environmental chemical composition of the churches and museums was inferred through the characterization of metal coupons exposed in their indoor and outdoor environments, whilst the aggressiveness related to physical factors such as temperature and relative humidity was inferred through the use of miniaturized monitors exposed only in the churches. With this monitoring, conservation strategies were proposed. For the well characterization of the metal coupons, exposed in the churches and museums or in simulated microenvironments, the syntheses and characterization of different Pb formates were essential. Finally, aiming at still improving the performance of the miniaturized monitors and increasing their applicability (in their future use as EN), a new device was constructed, and an internship was considered in the University of Aveiro, Portugal, for the development of an EN based on QCMs.

Coil coatings are durable  organic coatings used to protect metal sheets from corrosion and improve their aesthetic properties. Because of their extensive use, coil coatings have long been of interest for industrial and academic researchers. This interest has recently been furthered by a societal push towards the replacement of fossil-based raw materials with alternatives that are biobased and renewable. The aim of this licentiate thesis is to demonstrate how analyses on the macro-, micro-, and nanoscale can be used to better understand the degradation process of polyester-based coil coatings. The included manuscripts showcase methods for evaluating and comparing different coil coating formulations and for verifying accelerated weathering techniques. Multiple techniques, focusing on infrared (IR) spectroscopy and atomic force microscopy (AFM), were used to analyze coating systems before and after different types of weathering. IR data acquired from techniques without spatial resolution, such as attenuated total reflection (ATR) and photoacoustic spectroscopy (PAS) have been expanded upon with spatially resolved focal plane array (FPA) and s-SNOM  (scattering-type scanning near-field optical microscopy) measurements. Spatially resolved chemical data of coating cross sections were acquired and used to assess how the degradation at the surface and in the bulk was related. Additionally, differences between the degradation behavior of a standard fossil-based coating and a similar coating with biobased components as well as differences between the degradation caused by artificial and natural weathering was discussed. Nanoscale mechanical measurements of simplified coating surfaces showed that weathering increased nanomechanical stiffness and led to homogenization of mechanical properties on the local level. In addition, measurements with nanoscale FTIR correlated with macroscale FTIR. Even relatively minor changes in band intensities could be tracked on a local scale. Although the simplified samples were chemically homogeneous, nanoscale FTIR shows great promise for the assessment of local degradation of full systems. / Bandlackering är en process för att applicera stabila organiska beläggningar på metallytor för att skydda från korrosion och förbättra deras utseende. På grund av beläggningarnas omfattande användning så har utvärdering och analys av dem varit av intresse för både akademi och industri i flera årtionden. Detta långvariga intresse har ytterligare främjats av en ökade miljömedvetenhet och ett tryck att ersätta miljöfarliga och fossila råmaterial mot biobaserade och förnyelsebara alternativ. Målet med denna licentiatavhandling är att visa hur analysmetoder på makro-, mikro-, och nanonivå kan användas för att bättre förstå nedbrytning av bandlackerade beläggningar. Denna förståelse kan användas både för att utvärdera prestandan hos både nya redan befintliga system, men också för att kunna verifiera accelererade testmetoder vars mål är att minska tiden som krävs för utvärdering. Flera tekniker, med fokus på infraröd (IR) spektroskopi och atomkrafts-mikroskopi  (AFM) använts för att analysera beläggningar före och efter att de blivit utsatta för olika typer av aggressiva miljöer. Spektroskopiska data utan spatial upplösning som attenuerad totalreflektions FTIR (ATR) och fotoakustisk spektroskopi (PAS) har kompletterats med spatialt upplösta fokalplans array (FPA) och s-SNOM mätningar. Kemisk information med spatial upplösning har använts för att utvärdera hur nedbrytningen nära ytan relaterade till nedbrytningen längre ner i beläggningen. Likheter och skillnader i nedbrytningen som skedde i en standardbeläggning och ett system med biobaserade additiv jämfördes efter både väderbestendighets-testning som skedde utomhus och i labb. Skillnader mellan dessa exponeringsmetoder diskuterades också. Nanomekanisk analys med hjälp av atomkraftsmikroskopi användes för att bestämma lokala förändringar av mekaniska egenskaper i förenklade klarlacker. Mätningarna visade att exponeringar i aggressiva miljöer leder till en lokal homogenisering av mekaniska egenskaper och ökad styvhet. Utöver detta så utvärderades likheter och skillnader mellan FTIR spektra som tagits på makro- och nanonivå. Dessa mätningar gav lovande resultat för fortsatta ytanalyser. / <p>QC 2023-05-15</p>

Ein grundlegender Trend der modernen Mikro- und Optoelektronik ist die sinkende Größe der aktiven Elemente der Bauteile. Mit typischen Dimensionen im Bereich 1-10 nm werden Effekte des sogenannten quantenmechanischen Confinements bemerkbar, die die elektronischen und phononischen Eigenschaften der Materialien stark beeinflussen. Der aktuelle Entwicklungsstand von Nanotechnologie macht es möglich, Halbleiternanokristalle mit verschiedenen Strukturparametern wie Größe, Form und chemischer Zusammensetzung herzustellen, welche neue fundamentaleтhysikalische Eigenschaften zeigen. Gleichzeitig ist die Herausforderung, die Zusammenhänge von Struktur der Nanokristalle mit deren optischen, elektronischen und phononischen Eigenschaften zu erkunden, weiterhin relevant. Der Grund dafür besteht darin, dass klassische optische Methoden zur Untersuchung von makroskopischen Materialien und dünnen Schichten – Raman-, Infrarot- und Photolumineszenz-Spektroskopie, bei Anwendung auf Nanostrukturen nicht einzelne, sondern gleich eine Vielzahl von Nanoobjekten mit unterschiedlichen Größen, Formen, Zusammensetzungen etc. messen. Als Resultat davon sind die gemessenen Werte nicht sehr aussagekräftig, da effektiv über eine große Anzahl von Nanokristallen gemittelt wird, während der Beitrag von einzelnen Nanokristallen unter dem Detektionslimit liegen. Aus diesem Grund wurden die Methoden der plasmonverstärkten optischen Spektroskopie, inklusive oberflächenverstärkter Ramanstreuung (SERS, Surface Enhanced Raman Spectroscopy), Photolumineszenz (SEPL, Surface Enhanced Photoluminescence) und Infrarotabsorption (SEIRA, Surface Enhanced IR Absorption) in den letzten Jahren mit dem Ziel, das erreichbare Signal einzelner Halbleiternanostrukturen zu verbessern, stark vorangetrieben. Diese Methoden basieren auf der lokalen Verstärkung des elektromagnetischen Feldes nahe metallischer Nanostrukturen durch das Anregen lokalisierter Oberflächenplasmonenresonanz (LSPR, Localized Surface Plasmon Resonance) mittels Licht im sichtbaren oder infraroten Spektralbereich. Diese oberflächenverstärkten Methoden erlauben das Untersuchen des Phononenspektrum aus SERS-, SEPL- und SEIRA-Daten mit einer Sensitivität weit über der von konventionellen Methoden. Daher wurden in dieser Arbeit SERS- und SEPL-Experimente an CdSe/CdS Nanoplättchen, die auf Gold Nanoscheiben abgeschieden wurden, durchgeführt. Resonantes und nichtresonantes SERS sowie der Einfluss von Energietransfer und Purcell-Effekt in SEPL-Experimenten werden hier gezeigt. Mittels numerischer Simulation wurde die Struktur der Mikro- und Nanoantennen optimiert, um die Übereinstimmung ihrer LSPR- und der Phononenenergien der Halbleiternanokristall-Monolagen in SEIRA-Experimenten zu erreichen. Damit wurden die phononischen Eigenschaften dieser Halbleiternanokristall-Monolagen untersucht, was vorher mit konventioneller IR-Spektroskopie nicht möglich war. Ebenso wurde gezeigt, dass die Plasmonen der Nanoantennen effektiv mit darunterliegenden Materialien, z.B. SiO2, gekoppelt werden können. Die Eindringtiefe dieser Kopplung wurde durch Messung an Nanoantennen auf verschieden dicken SiO2-Lagen bestimmt und die Plasmon-Phonon-Wechselwirkung, die zur Renormalisierung von Phononen- und Plasmonenspektren führt, gefunden. Teile der Arbeit sind in J. Chem. Phys., 153, 16, 2020, Beilstein J. Nanotechnol., 9, 2646–2656, 2018, J. Phys. Chem. C, 121, 10, 5779–5786, 2017, und Beilstein J. Nanotechnol. 7, 1519–1526, 2016 veröffentlicht. Es ist zu beachten, dass die Grenze des Auflösungsvermögens für Optik auch für die oberflächenverstärkte Spektroskopie gilt. Um diese Grenze zu umgehen wurde spitzenverstärkte Ramanspektroskopie (TERS, Tip Enhanced Raman Spectroscopy) verwendet. TERS kombiniert die hohe räumliche Auflösung von AFM (Rasterkraftmikroskopie, Atomic Force Microscopy) mit den analytischen Fähigkeiten der Ramanspektroskopie. Eine Möglichkeit, das lokale elektromagnetische Feld und damit auch das gemessene TERS-Signal zu verstärken, besteht darin, plasmonische Substrate zu verwenden, wobei das zu untersuchende Objekt zwischen diesem Substrat und der Spitze des TERS-Spektrometers platziert wird, da dort die Verstärkung des elektromagnetischen Feldes am größten ist (sogenanntes gap-mode TERS). Daher haben wir in dieser Arbeit den Einfluss eines solchen plasmonischen Substrates auf die TERS-Messungen von phononischen Eigenschaften extrem dünner Lagen (Submonolage) von Nanokristallen untersucht. Vorteile verschiedener TERS-Methoden werden demonstriert: konventionelles TERS, gap-mode TERS und resonantes gap-mode TERS. TERS-Mapping wurde auf den gleichen Nanoscheiben mit CdSe-Nanokristallen durchgeführt und der Unterschied dieser Mappings für zwei verschiedene, für die Ramanspektroskopie genutzte Wellenlängen mit elektrodynamischer Modellierung erklärt. Mit gap-mode TERS war es möglich, einzelne CdSe/CdS Nanoplättchen sichtbar zu machen und ihre Phononenmoden zu erforschen. Teile dieser Arbeit sind in Nanoscale Adv., 2, 11, 5441–5449, 2020 veröffentlicht. Eine weitere neue und intensiv vorangetriebene Methode zur Nanoanalyse ist die nano-FTIR (Fourier Transformed Infrared Spectroscopy, Fouriertransformierte Infrarotspektroskopie) genannte Kombination von IR-Spektroskopie mit Rasterkraftmikrokopie. Im Gegensatz zu TERS, bei dem Licht von einer einzelnen, schmalen Laserlinie inelastisch gestreut wird, verwendet nano-FTIR eine breitbandige Infrarotquelle. Daher wird in nano-FTIR das gesuchte Nahfeld-Signal durch Demodulation des Detektorsignals extrahiert. Durch nano-FTIR-Spektroskopie wurde in dieser Arbeit der Oxidgehalt x in SiOx-Nanodrähten auf der Nanometerskala bestimmt. Weiterhin wurden Plasmon-Phonon-Wechselwirkungen einer einzelnen Nanoantenne auf Si/SiO2 Substrat ebenfalls auf der Nanometerskala untersucht. Teile dieser Arbeit sind in Appl. Surf. Sci., 152583, 2022 veröffentlicht. Zuletzt demonstriert diese Arbeit auch die Kombination von polarisiertem TERS und nano-FTIR für die Untersuchung von hexagonalen AlN-Nanoclustern. Es wird gezeigt, dass die polarisierten TERS-Experimente sensitiv sind für Oberflächenplasmonenmoden mit unterschiedlichen Symmetrien, wie sie charakteristisch für AlN-Nanocluster sind. Der Einfluss der Polarisierung auf die TERS-Mappings eines einzelnen AlN-Clusters und Nanodrahts wird experimentell gezeigt und erklärt. Weiterhin konnte festgestellt werden, dass die nano-FTIR-Spektren, ähnlich den TERS-Daten, eine Sensitivität für Oberflächenmoden zeigen und neue Informationen über die Winkelverteilung dieser AlN-Oberflächenphononen im Nanokristall auf der Nanometerskala liefern.:Table of Contents 1. Elementary excitations in hybrid semiconductor/metal nanostructures 10 1.1. Phonons and excitons in semiconductor nanocrystals: Raman, IR and PL spectroscopies 11 1.2. Raman scattering 15 1.3. Plasmons in metal nanoclusters 17 1.4. Photoluminescence 20 1.5. Surface-enhanced Raman spectroscopy (SERS), IR absorption (SEIRA), and Photoluminescence (SEPL) in hybrid semiconductor/metal nanostructures: Principles and enhancement mechanisms 22 1.6. Tip-enhanced Raman spectroscopy (TERS) and Photoluminescence (TEPL) of semiconductor nanostructures 24 1.7. From conventional Fourier transform infrared (FTIR) to nano-FTIR spectroscopy 26 1.8. Summary 27 2. Experimental Methods 28 2.1. Fabrication of metal nanostructures 28 2.1.1. Metal evaporation 28 2.1.2. Fabrication of TERS cantilevers 28 2.1.3. Photo- and Nanolithography of metal micro-and nanostructures 28 2.2. Fabrication of semiconductor nanocrystals by Langmuir-Blodgett technology and their TEM characterization 32 2.3. Fabrication and TEM characterization of CdSe/CdS nanoplatelets 35 2.4. Fabrication of SiOx lines by local anodic oxidation 36 2.5. Molecule beam epitaxy (MBE) of AlN nanoclucters on Si(111) 37 2.6. Microscopy and spectroscopy characterization methods of semiconductor and metal nanostructures at micro- and nanoscale 38 2.6.1. Micro- and nano-Raman, and Photoluminescence spectroscopies 38 2.6.2. Fourier transform infrared (FTIR) spectroscopy 39 2.6.3. Atomic Force Microscopy (AFM) 41 2.6.4. NeaSNOM platform for Nano-FTIR spectroscopy 43 2.7. Summary 45 3. Surface- enhanced Raman, PL and IR spectroscopies of hybrid semiconductor/metal nanostructures 46 3.1. SERS and SEPL of CdSe/CdS nanoplatelets on Au nanodisks 46 3.2. IR spectroscopy of hybrid semiconductor/metal nanostructures 52 3.2.1. Plasmon modes in gold nanoantennas on Si/SiO2 52 3.2.1.1. Plasmon modes in micro- and nanoantennas of various morphologies 57 3.2.1.2. Activation of even modes of localized surface plasmon in antennas 61 3.2.2. SEIRA of optical phonons in CdS, CdSe, PbS nanocrystals on Au micro- and nanoantennas 64 3.3. Summary 67 4. Nanoscopy of hybrid semiconductor/metal nanostructures 69 4.1. TERS of CdSe NCs on different plasmonic substrates 69 4.2. Gap-mode TERS imaging of CdSe NCs for different excitation energies 76 4.3. Gap-mode TERS imaging of CdSe/CdS nanoplatelets 79 4.4. Nano-FTIR Spectroscopy of SiOx nanowires 81 4.5. Plasmon-phonon nanoscale interaction in an Au nanoantenna on a thin SiO2 layer 85 4.6. Summary 87 5. Comparative nanoscale analysis of surface optical modes in AlN nanostructures 89 5.1. TERS mapping of a single AlN hexagonal nanocluster 89 5.2. Hyperspectral Nano-FTIR imaging of a single AlN hexagonal nanocluster 91 5.3. Polarized TERS mapping and Hyperspectral Nano-FTIR imaging of a single AlN nanowire 95 5.4. Summary 98 6. Summary 99 7. Appendix 101 8. Acknowledgements 104 9. Lebenslauf 105 10. Publications 106 11. Erklärung 108 12. Bibliography 109 13. List of Figures 125