Organické elektronické zariadenia sú vyvíjané ako vhodné riešenia senzorov pre bioelektroniku, a to najmä kvôli dobrej biokompatibilite organických polovodičov v nich použitých. Takzvané biosenzory dokážu premeniť elektrochemické procesy na elektronický signál. Matrica takýchto biosenzorov môže simultánne skenovať množstvo biologických vzoriek, alebo rôznych tkanív v živých systémoch. Aktívnou súčasťou zariadenia je organický elektrochemický tranzistor (OECT). V tejto práci je diskutovaný teoretický rámec fungovania takéhoto zariadenia, jeho elektrická charakterizácia, aplikácia v biosenzoroch na báze buniek, spôsoby výroby a aktuálnym stavom techniky v oblasti organickej elektroniky. Experimentálna časť obsahuje konkrétne výrobné postupy vývoja OECT zariadení, ktoré boli použité v našom laboratóriu. Hlavný dôraz sa kladie na schopnosť vyrobených zariadení detekovať reakciu a monitorovať stimuláciu elektrogenných buniek. Za týmto účelom boli vyvinuté matice mikroelektródových OECT zariadení založených na polovodivom polyméri PEDOT:PSS. Tieto boli vyrobené s využitím bežnými tlačiarenských techník (atramentová tlač a sieťotlač) spolu so štandardnými litografickými postupmi. Najnovšie nami vyvinuté zariadenia dosahujú najväčšieho zosílením signálu, g = 2,5 mS a časovú konštantu t = 0,15 s. Tieto zariadenia sú porovnateľné, často dokonca lepšie ako niektoré iné najmodernejšie a plne litograficky pripravené senzory.

This work presents a new approach of fabricating arrays of electrodes, separated by sub-micrometer gaps allowing the systematic investigation of electric properties of organic semiconductors. The laterally stacked devices are fabricated by using a trench isolation technique for separating different electrical potentials, as it is known for micromachining technologies like Single Crystal Reactive Ion Etching and Metallization (SCREAM). The essential part of this process is the patterning of sub-micrometer trenches onto the silicon substrate in a single lithographic step. Afterwards, the trenches are refilled by SiO2 to allow the precise tuning of the electrode separation gap. The metal electrodes are formed via magnetron sputtering. This technological approach allows us to fabricate device structures with a transport channel length in the range of 100-250 nm by conventional photolithography. In this experiment, three different metals like Au, Co, and Ni were used as the electrode materials, while copper phthalocyanine, being deposited by thermal evaporation in high vacuum, was employed as the organic semiconductor under evaluation. The final aim has been study of spin transport through the organic channel in varied geometry.

Recently, bilayer resist processing combined with development in hydro uoroether (HFE) solvents has been shown to enable single color structuring of vacuum-deposited state-of-the-art organic light-emitting diodes (OLED). In this work, we focus on further steps required to achieve multicolor structuring of p-i-n OLEDs using a bilayer resist approach. We show that the green phosphorescent OLED stack is undamaged after lift-off in HFEs, which is a necessary step in order to achieve RGB pixel array structured by means of photolithography. Furthermore, we investigate the in uence of both, double resist processing on red OLEDs and exposure of the devices to ambient conditions, on the basis of the electrical, optical and lifetime parameters of the devices. Additionally, water vapor transmission rates of single and bilayer system are evaluated with thin Ca film conductance test. We conclude that diffusion of propylene glycol methyl ether acetate (PGMEA) through the uoropolymer film is the main mechanism behind OLED degradation observed after bilayer processing.

This paper describes simulation, technology- and process development for the manufacturing of single mode polymeric waveguides by photolithography. Simulations for single mode operation in O- and C-band are carried out. Waveguides are directly patterned with UV-photolithography using Ormocere®-material. Fiber to waveguide coupling and near field are characterized.

The subject of this thesis is the investigation of organic microcavities with implemented unstructured and laterally structured metal layers. The optical properties are studied by means of various spectroscopic techniques and are compared to conventional metal-free devices. It is shown that the large expected absorption caused by the embedded metal is reduced compared to the case of a free-standing metal layer of the same thickness. As a consequence of the interaction of the photonic cavity mode with the metallic structures, two new coupled modes emerge which are called Tamm plasmons. The strength of this coupling and the resulting spectral difference of these modes are defined by the thickness of both the metal layer and the adjacent dielectric layers. These control parameters enable the optimization of the structural design. Accordingly, coherent emission from Tamm plasmons is realized at room temperature. An analytical approach is developed accounting for the experimentally observed polarization splitting of detuned resonances. Next, laterally structured metal layers embedded into organic microcavities are considered. The structuring leads to a confinement of the photonic density of states evident from a clear discretization in energy of the corresponding modes. Applying a photolithographic technique to structure the metal layer into a pattern of regularly placed stripes leads to additional effects due to the resulting periodicity. By exciting this hybrid structure above a certain threshold, periodic arrays of localized cavity modes and metal-based Tamm plasmons are generated. These Bloch-like excited states are capable of phase coupling across the grating. Additionally, surface plasmon polaritons (SPPs) are excited propagating at the interface of the silver and the adjacent dielectric layers. Thanks to the periodicity of the metallic stripes, SPPs are subject to efficient Bragg scattering into the light cone in air. Modes up to order number 30 are detectable as quasi-linear periodic lines in the dispersion pattern. A Fourier analysis reveals an in- or out-of-phase coupling of the modes and a spread of the coherence over macroscopic distances of more than 40 µm. This strategy of embedding metal patterns into an organic microcavity yields a viable route towards electrically contacted organic solid-state lasers. / In dieser Arbeit werden erstmals dünne, unstrukturierte sowie lateral strukturierte metallische Schichten in organische Mikroresonatoren eingebettet und anschließend die optischen Eigenschaften mittels spektroskopischer Verfahren untersucht. Es zeigt sich, dass die erwarteten hohen optischen Verluste durch die Absorption des elektrischen Feldes im Metall deutlich reduziert sind, verglichen mit dem Fall einer freistehenden, nicht eingebetteten Metallschicht gleicher Dicke. Als Folge der Wechselwirkung der photonischen Kavitätsmode mit dem Metall spaltet diese in zwei miteinander gekoppelte Moden auf. Diese neuartigen Moden werden als Tamm-Plasmonen bezeichnet. Die Kopplung sowie die spektrale Differenz beider Moden ist zum einen durch die optischen Eigenschaften und die Dicke der eingebetteten Metallschicht definiert, zum anderen durch die optische Dicke der angrenzenden dielektrischen Schichten. Dadurch ist eine Optimierung des Systems im Hinblick auf Absorption und Emissionswellenlänge der Bauteile möglich, so dass selbst bei Raumtemperatur kohärente Emission eines Tamm-Zustands erzielt werden kann. Eine erarbeitete analytische Rechnung bestätigt und erklärt die experimentell gemessene, polarisationsabhängige Aufspaltung der auftretenden resonanten Moden. Im zweiten Teil der Arbeit sind organische Mikroresonatoren, deren eingebettete Metallschicht in lateraler Richtung auf verschiedene Weisen strukturiert sind, Gegenstand der Untersuchungen. Als Folge dieser Strukturierung kommt es zur lateralen Beschränkung der photonischen Zustandsdichte, was durch eine Diskretisierung der Energiespektren der resultierenden optischen Moden experimentell nachweisbar ist. Werden periodische Metallstreifen mittels Photolithographie erzeugt, so kommt es neben einer weiteren Beeinflussung der Zustandsdichte auch zu Effekten, die durch diese Periodizität bedingt sind. Entsprechend reproduziert sich die Kavitätsmode mehrfach im Impulsraum. Oberflächenplasmonen, die auf der Grenzfläche zwischen dem Metall und den dielektrischen Schichten propagieren, werden auf Grund der Periodizität bis in den experimentell zugänglichen Lichtkegel gestreut. Dabei werden Plasmonenresonanzen bis hin zur 30. Ordnung gemessen. Im letzten Experiment werden derart periodisch strukturierte Metall-Organik-Mikroresonatoren auf ihre Lasertätigkeit hin untersucht. Eine lokal begrenzte optische Anregung mittels eines gepulsten Lasers führt zur Ausbildung verschiedener Bloch-ähnlicher Moden, deren Kohärenz sich lateral bis zu 40 µm ausbreitet. Eine Fourieranalyse zeigt eindeutige und feste Phasenbeziehungen zwischen angrenzenden Maxima der Moden. Zusammenfassend ergeben sich interessante metall-organische Systeme, die minimale Absorption und niedrige Laserschwellen aufweisen und die prinzipielle Eignung zur elektrischen Kontaktierung besitzen.

This thesis presents the modeling and fabrication of a new solid-state device meant to be used for digital logic circuits. Most current logic circuits are based on MOSFETs. The new logic device uses some of the same operating principles, but also relies on optical illumination to provide input power. In order to obtain the desired current-voltage behavior of the new device, the Silvaco (Atlas) device simulation was used to give some insight into the correct doping levels in the semiconductor and device geometries. Prototypes were fabricated on p-type silicon wafers using CMOS fabrication processes including oxide growth, photolithography, precise plasma or chemical wet etching, diffusion processes, and thin film evaporation. Electrical measurements were done by using an HP4156 parameter analyzer to measure several output voltage signals at one time while an illuminating the device with laser light. The current-voltage characteristics under different biasing conditions with an optical illumination condition were measured and showed characteristics similar to an nMOS transistor.

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A near-field technique known as evanescent interferometric lithography allows for high resolution imaging. However its primary limitation is that the image exponentially decays within the photoresist due to physical limits. This thesis aims to overcome this limitation and presents a method to considerably enhance the depth of focus of images created using evanescent interferometric lithography by using a material underlay beneath the photoresist. A key enabler of this is the understanding that evanescent fields couple to surface states and operating within proximity of a resonance, the strength of the coupling allows for considerable energy extraction from the incident beam and redistribution of this energy in a photoresist cavity. This led to the analysis of the Fresnel equations, which suggested that such coupling was in fact the result of an enhanced reflectance that takes place at boundaries of carefully chosen materials. While it is known that metals and lossy dielectrics result in surface plasmon polaritons (SPP) and surface exciton polaritons (SEP) as conventional solutions to the Fresnel reflection equations for the TM polarization of light, there is no such naturally occurring surface state that allows evanescent wave enhancement with the TE polarization of light. Further investigation of the Fresnel reflection equations revealed both for TM and TE that in fact another solution exists that is but unconventional to enhance the reflectivity. This solution requires that one of the media have a negative loss. This is a new type of surface resonance that requires that one of the media be a gain medium; not one in the optical pumped sense but one that would naturally supply energy to a wave to make it grow. This new surface resonance is also a key result of this thesis. Clearly, however this is only a hypothetical solution as a real gain medium would violate the conservation of energy. However, as it is only the reflectance of this gain medium that is useful for evanescent wave enhancement, in fact a multilayered stack consisting of naturally occurring materials is one way to achieve the desired reflectivity. This would of course be only an emulation of the reflectivity aspect of the gain medium. This multilayered stack is then an effective gain medium for the reflectivity purposes when imaging is carried out at a particular NA at a particular wavelength. This proposal is also a key idea of this thesis. At λ = 193 nm, this method was used to propose a feasible design to image high resolution structures, NA = 1.85 at an aspect ratio of ~3.2. To experimentally demonstrate the enhancements, a new type of solid immersion test bed, the solid immersion Lloyd's mirror interference lithography test-bed was constructed. High quality line and space patterns with a half-pitch of 55.5 nm were created using λ = 405 nm, corresponding to a NA of 1.824, that is well in the evanescent regime of light. Image depths of 33-40 nm were seen. Next, the evanescent image was coupled to an effective gain medium made up of a thin layer of hafnium oxide (HfO) upon silicon dioxide (SiO2). This resulted in a considerable depth enhancement, and 105 nm tall structures were imaged. The work in this thesis details the construction of the solid immersion lithography test-bed, describes the implementation of the modeling tools, details the theory and analysis required to achieve the relevant solutions and understanding of the physical mechanism and finally experimentally demonstrates an enhancement that allows evanescent interferometric lithography beyond conventional limits.