It is well known that the implementation of flexible organic electronic devices (FEDs) in our everyday life improve and revolutionize several aspects of our behavior. Although there has been considerable progress in the area of flexible inorganic devices (based on Si), there are numerous advances in the organic (semiconducting, conducting and insulating), inorganic and hybrid (organic-inorganic) materials that exhibit customized properties and stability, and in the synthesis and preparation methods, which are characterized by a significant amount of multidisciplinary efforts. The understanding of the organic material properties can lead to the fast progress of the functionality and performance of flexible organic electronic devices. An crucial ingredient for this is the strong interdisciplinary nature of the area of organic electronics, which brings together experts in chemistry, physics, and engineering, removing the traditional boundaries between the individual disciplines. Therefore, the understanding of the properties of organic insulators, semiconductors, and conductors as well as the effect of their synthesis process, microstructure and morphology is the goal of the current research efforts. In this work, we summarize on the latest advances in the fields of organic (semi-) conducting materials and hybrid barrier layers to be used as active layers and for the encapsulation of the materials components for the production of FEDs (such as flexible organic light-emitting diodes, and organic solar cells).

A hybrid process compatible with reel-to-reel manufacturing is developed for ultra low-cost large-scale manufacture of disposable microfluidic chips. It combines ultra-short laser microstructuring and lamination technology. Microchannels in polyester foils were formed using focused, high-intensity femtosecond laser pulses. Lamination using a commercial SU8-epoxy resist layer was used to seal the microchannel layer and cover foil. This hybrid process also enables heterogeneous material structuration and integration.

The microstructure of thin deposits of poly(3-hexylthiophene) on silicon surfaces is investigated as a function of the solution concentration, the maturation time and the solvent nature, with the aim of generating one monolayer of P3HT nanofibers on the surface. These films are then exposed to a NOPF6 solution, in order to oxidize the conjugated system and to produce conducting nanostructures. The effect of the chemical doping on the microscopic morphology and the electrical properties is analyzed on the basis of AFM and I-V measurements.

Non-destructive method of spectroscopic ellipsometry (SE) from IR to FUV was applied to study PEDOT/PSS thin films deposited by spin coating from aqueous dispersions of the material with different N,N-Dimethylformamide (DMF) volume percent. In our work we used the Tauc-Lorentz model to describe the dielectric function of PEDOT/PSS:DMF films in the Vis-FUV energy region. First, the spectrum analysis showed that the thickness and the fundamental band gap Eg of the film is being decreased with the increase of DMF content in the dispersion. Taking into account that the heating temperature is below the boiling point of DMF we assume that DMF molecules are incorporated in the film volume and act as dopants. Further more, this means that carrier concentration is being increased and thus we have higher electrical conductivity. The existence of DMF molecules in the film proved from FTIR SE, which can probe the bonding structure of the materials. The results showed lowering of peak intensity assigned to PEDOT/PSS and appearing of peaks assigned to DMF in the imaginary part of spectrum. In conclusion, SE is a potential tool for the evaluation of electronic properties for conductive polymers.

The precise control of organic thin film processing by organic vapor phase deposition (OVPD®) is presented and analyzed on device level. OVPD® offers accurate and individual control of deposition layer properties like mixing of several materials (co-deposition) and the control of various morphologies by a wide process parameter space given by, e.g. substrate temperature, deposition rate and pressure. The benefit of precise co-deposition is demonstrated by an OLED with a sensitive twofold-doped emissive layer and revealed a doping level of 0.26% for the red dopant with a std. dev. of 0.38%. The effect of the various morphologies is investigated by optimizing the efficiency of molecular organic solar cells consisting of copper phthalocyanine (CuPc) and C60. With defined process parameters efficiencies of up to 3.0% were demonstrated.

In this work we present a fabrication method for developing thermal sensors on flexible organic substrates. The constructed devices consist of Pt resistors which are directly integrated to the copper tracks of a flexible copper-clad laminate. They reside on top of a 12 $\mu $m thick SU-8 planarization layer, while a sacrificial layer utilized by the negative photoresist ma-N was used in order to define the resistor pattern. The resistors can act as both heating and temperature sensing elements, while due to small thickness and the low thermal conductivity of the Kapton substrate, a very effective thermal isolation is achieved. The minimum radius of curvature of the fabricated devices was found to be 5 mm. As the device is in direct communication to the macrowolrd, the need for wire bonding is eliminated, while the final surface of the produced sensor is relatively planar. The overall process is simple and cost-effective with minimal requirements in fabrication time. The potential application field of the presented devices is considered quite extensive as they can be directly expanded into flexible sensors able to measure quantities such as fluid flow rate, displacement or vacuum.

A permanent growth of the thin-film electronics market stimulates the development of versatile technologies for patterning thin-film materials on flexible substrates. High repetition rate lasers with a short pulse duration offer new possibilities for high efficiency structuring of conducting, semi-conducting and isolating films. Lasers with the picosecond pulse duration were applied in structuring the complex multilayered Cu(InGa)Se2 (CIGS) solar cells deposited on the polyimide substrate. The wavelength of laser radiation was adjusted depending on optical properties both of the film and the substrate. A narrow processing window of laser fluence and pulse overlap was estimated with both 1064 nm and 355 nm irradiation to remove the molybdenum backcontact off the substrate. The selective removal of ITO, ZnO and CIGS layers was achieved with 355 nm irradiation in the multilayer structure of CIGS without significant damage to the underneath layers. Use of the flat-top laser beam profile should prevent inhomogeneity in ablation. The EDS analysis did not show residues of molybdenum projected onto the walls of ablated channel due to melt extrusion. Processing with picosecond lasers should not cause degradation of photo-electrical properties of the solar cells but verification is required.

In polymer light emitting diodes (PLEDs) each semiconducting polymer chain consists of a large number of conjugated segments linked by kinks or twists and each one of them behaves like a separated straight strand. The length and orientation of the conjugated strands relative to the electrodes surface depend on the deposition conditions used. Atomistic results have shown that the molecular properties of the conjugated strands depend on their length, which can affect the electronic processes involved in PLEDs. The aim of this work is to study the influence of the average conjugation length within the polymer layer on charge injection, trapping and recombination in PLEDs for all polymer strand orientations relative to the electrodes surface obtained experimentally by different techniques. For that purpose we use a mesoscopic model that considers the morphology and the molecular properties of the polymer. Our results show that by increasing the average conjugation length of the active polymer layer the amount of charge injected into the device increases and the recombination probability occurs preferentially in segments longer than the average conjugation length, both effects having implications on the performance of polymer LEDs.

Evanescent coupling is used to couple light from an organic Lambertian emitter into a single mode planar waveguide. Either an organic light emitting diode (OLED) directly excites the waveguide mode or an OLED pumps a photoluminescent (PL) material layer located directly on the waveguide. At the out-coupling grating the guided light is diffracted onto an array of organic photodiodes acting as a spectrometer. A spectral resolution of down to 16 nm could be achieved with integrated optoelectronic system.

The elucidation of physical properties of organic materials is important for further optimization of related electronic and optoelectronic devices. Here we review briefly various first-principles computational tools for the modeling of these materials by investigating key structural, electronic, and chemical properties of prototype organic semiconductors. In particular, we discuss the site-selectivity for band formation in pentacene and rubrene, hydrogenation and transformations of metal-free phthalocyanines, and the bonding topology in a hybrid organic-inorganic system.

A complete framework for characterization and modelling of organic semiconductor materials is here reported. Multifunctional testbeds have been developed to analyze different organic semiconductors through hybrid demonstrators.

The recent development of innovative organic materials with intriguing features such as their flexibility, lightness, low cost and easy manufacturability, has driven researchers to develop innovative smart applications based on such kind of materials. In this work, all-organic electromechanical transducers, with both sensing and acting capabilities are proposed. The actuator and sensor models have been identified by using a grey box approach, as a function of membrane geometric parameters. The obtained models have been validated through comparison among estimated and experimental data.