Narrow Plasmon Resonances In Hybrid Systems

Advances in understanding the interactions between light and subwavelength materials have enabled the author and his collaborators to tailor unique optical responses at the nanoscale. In particular, metallic nanostructures capable of supporting surface plasmons can be designed to possess spectrally narrow plasmon resonances, which are of particular interest due to their exceptional sensitivity to their local environment. In turn, combining plasmonic nanostructures with other materials in hybrid systems allows this sensitivity to be exploited in a broad range of applications. In this book the author explores two different approaches to attaining narrow plasmon resonances: in gold nanoparticle arrays by utilising diffraction coupling, and in copper thin films covered by a protective graphene layer. The performance of these resonances is then considered in a number of applications. Nanoparticle arrays are used along with an atomic heterostructure as elements in a nanomechanical electro-optical modulator that is capable of strong, broadband modulation. Strong coupling between diffraction-coupled plasmon resonances and a gold nanoparticle array and guided modes in a dielectric slab is used to construct a hybrid waveguide. Lastly, the extreme phase sensitivity of graphene-protected copper is used to detect trace quantities of small toxins in solution far below the detection limit of commercial surface plasmon resonance sensors.

The special optical properties of subwavelength metallic structures have opened up for numerous applications in different fields. The interaction of light with metal nanostructures leads to the excitation of collective oscillations of conduction-band electrons, known as plasmons. These plasmon excitations are responsible for the high absorption and high scattering of light in metallic nanostructures. High absorption of light and the subsequent temperature increase in the nanostructures make them suitable as point-like heat sources that can be controlled remotely by light. The research presented in this thesis focuses on the development and studies of hybrid devices that combine light-induced heating in plasmonic nanostructures with other materials and systems. Particular focus is put on hybrid organic-inorganic systems for applications in energy harvesting as well as in heat and radiation sensing. Harvesting energy from light fluctuations was achieved in a hybrid device consisting of plasmonic gold nanodisk arrays and a pyroelectric copolymer. In this concept, fast and efficient light-induced heating in the gold nanodisks modulated the temperature of the pyroelectric layer, which could be used to extract electrical energy from fluctuations in simulated sunlight. Integrating plasmonic nanostructures with complementary materials can also provide novel hybrid sensors, for monitoring of temperature, heat flux and radiation. In this thesis work, a hybrid sensor was designed based on the combination of a plasmonic gold nanohole layer with a pyroelectric copolymer and an ionic thermoelectric gel. The gold nanohole arrays acted both as broadband light absorbers in the visible to near-infrared spectral range of the solar spectrum and also as one of the electrodes of the sensor. In contrast to the constituent components when used separately, the hybrid sensor could provide both fast and stable signals upon heat or radiation stimuli, as well as enhanced equilibrium signals. Furthermore, a concept for heat and radiation mapping was developed that was highly sensitive and stable despite its simple structure. The concept consisted of a gel-like electrolyte connecting two separated metal nanohole electrodes on a substrate. Resembling traditional thermocouples, this concept could autonomously detect temperature changes but with several orders of magnitudes higher sensitivity. Owing to its promising sensing properties as well as its compatibility with inexpensive mass production methods on flexible substrates, such concept may be particularly interesting for electronic skin applications for health monitoring and for humanoid robotics. Finally, we improved the possibilities for the temperature mapping of the concept by modifying the structure from lateral to vertical form. Similar to the lateral device, the vertical temperature sensor showed high temperature sensitivity and stability in producing signals upon temperature changes.

Metal-semiconductor nanostructures represent an important new class of materials employed in designing advanced optoelectronic and nanophotonic devices, such as plasmonic nanolasers, plasmon-enhanced light-emitting diodes and solar cells, plasmonic emitters of single photons, and quantum devices operating in infrared and terahertz domains. The combination of surface plasmon resonances in conducting structures, providing strong concentration of an electromagnetic optical field nearby, with sharp optical resonances in semiconductors, which are highly sensitive to external electromagnetic fields, creates a platform to control light on the nanoscale. The design of the composite metal-semiconductor system imposes the consideration of both the plasmonic resonances in metal and the optical transitions in semiconductors - a key issue being their resonant interaction providing a coupling regime. In this book the reader will find descriptions of electrodynamics of conducting structures, quantum physics of semiconductor nanostructures, and guidelines for advanced engineering of metal-semiconductor composites. These constituents form together the physical basics of the metal-semiconductor plasmonics, underlying many effective practical applications. The list of covered topics also includes the review of recent results, such as the achievement of a strong coupling regime, and the preservation of non-classical statistics of photons in plasmonic cavities combined with semiconductor nanostructures.

This two-volume work covers ultrafast structural and electronic dynamics of elementary processes at solid surfaces and interfaces, presenting the current status of photoinduced processes. Providing valuable introductory information for newcomers to this booming field of research, it investigates concepts and experiments, femtosecond and attosecond time-resolved methods, as well as frequency domain techniques. The whole is rounded off by a look at future developments.

The Drug Discovery Handbook gives professionals a tool to facilitate drug discovery by bringing together, for the first time in one resource, a compendium of methods and techniques that need to be considered when developing new drugs. This comprehensive, practical guide presents an explanation of the latest techniques and methods in drug discovery, including: Genomics, proteomics, high-throughput screening, and systems biology Summaries of how these techniques and methods are used to discover new central nervous system agents, antiviral agents, respiratory drugs, oncology drugs, and more Specific approaches to drug discovery, including problems that are encountered, solutions to these problems, and limitations of various methods and techniques The thorough coverage and practical, scientifically valid problem-solving approach of Drug Discovery Handbook will serve as an invaluable aid in the complex task of developing new drugs.

This book, edited by two of the most respected researchers in plasmonics, gives an overview of the current state in plasmonics and plasmonic-based metamaterials, with an emphasis on active functionalities and an eye to future developments. This book is multifunctional, useful for newcomers and scientists interested in applications of plasmonics and metamaterials as well as for established researchers in this multidisciplinary area.

This work pursues a novel route to functionalizing large surfaces with hybrid nanoparticles. It also casts new light on the combined use of surface plasmon resonance and X-rays. SPR spectroscopy is employed to study Au-based plasmonic nanostructures fabricated by novel methods, and a new experimental device is developed combining SPR with X-ray absorption spectroscopy at a synchrotron beamline. Using the new SPR-XAS setup developed in this work, the author has studied in-situ and real-time effects of X-ray irradiation in materials such as glasses and Co-phthalocyanines.

Comprehensive Nanoscience and Technology, Second Edition, Five Volume Set allows researchers to navigate a very diverse, interdisciplinary and rapidly-changing field with up-to-date, comprehensive and authoritative coverage of every aspect of modern nanoscience and nanotechnology. Presents new chapters on the latest developments in the field Covers topics not discussed to this degree of detail in other works, such as biological devices and applications of nanotechnology Compiled and written by top international authorities in the field