Transparente Elektroden auf Kunststofffolien

Transparent electrodes have gained a considerable importance in various fields, like e.g. touchscreen devices. Future applications will require higher performance with regard to both electrical and optical properties and they will require lower cost. Today most electrodes are made of transparent conducting oxides like indium tin oxide (ITO). These materials can be sputtered from ceramic targets by dc sputtering processes with simple process control setups. Polymer films can be coated with these materials in vacuum roll coaters. These systems allow the sputtering processes to be run during an unwind‐rewind‐cycle of the roll. Sheet resistance values as low as 20 Ω_squ can be achieved by this technology. Lower resistance values require different approaches. A new and very effective solution is the superposition of the transparent oxide with a metal network. However, also approaches which completely base on organic materials are under investigation. These solutions benefit from the progress in organic conductors. They can be made without any vacuum coating technology. Besides the low sheet resistance also the mechanical robustness against bending is an important advantage of full‐organic approaches.     

Aufgedampfte SiOx Barriereschichten unter monoaxialem Stress

SiO_x barrier layers under uniaxial stress For the study of the impact of defined mechanical uniaxial load on the gas barrier effect of a PET (Polyethylenterephthalate) film coated with silicon oxide SiO_x a measurement device was designed. The developed system is modular and can be combined to measure both water vapour and oxygen transmission rate. The gas permeation was measured after a given strain and after unloading the strain on relaxed films.The results show that strain above 1 % can be critical for the increase of gas permeation of coated films under constant stress and 4 % for relaxed film.     

Transparente Elektroden aus Silber

Transparent electrodes made of silver Thin coatings of silver are used in heat control windows. They have a high conductivity and a high transmittance, especially in the visible range of the spectrum. The transmittance decreases in the near infrared, which can be compensated by gains due to an efficient utilisation of interferences. Silver coatings can be produced at low cost. Especially, it is possible to deposit them also on flexible foils. By additional dielectric layers, further demands can be fulfilled, without an impairment of the conductivity. Examples are the prevention of barriers, the adjustment of the work function or the stabilisation against subsequent processes. By this, silver electrodes are of specific interest for organic light emitting diodes or solar cells.     

Transparente leitfähige Nitride

Transparent conductive nitrides – New perspectives in device design More than 20 years after the pioneer of the GaN LED Nobel laureate Shuji Nakamura published that germanium is an inferior dopand for GaN when compared to silicon we showed that the opposite is true in regard of achievable n-type doping concentration. With Ge-doped GaN now device performance can be improved and new device structures realized. As transparent highly conductive nitride (TCN) new application fields emerge for GaN, in particular the replacement of ITO. Besides many potential applications Ge-doped GaN layers also show interesting physics as a new quasiparticle, the Collexon.     

Transparente leitfähige Elektroden

Transparent conductive oxides and alternative transparent electrodes for organic photovoltaics and OLEDs Organic, photoactive devices, such as OLEDs or organic solar cells, currently use indium tin oxide (ITO) as transparent electrode. Whereas ITO is industry‐proven for many years and shows very good electrical and optical properties, its application for lowcost and flexible devices might not be optimal. For such applications innovative technologies such as networkbased metal nanowire or carbon nanotube electrodes, graphene, conductive polymers, metal thin‐films and alternative transparent conductive oxides emerge. Although some of these technologies are rather experimental and far from application, some of them have the potential to replace ITO in selected applications.     

Transparente Kratzschutzbeschichtungen für Kunststoff

Transparent scratch resistant coatings on plastics Today automotive glazing must show more and more functional properties and fulfill demands like low weight, easy assembling and demounting, high design flexibility and recycling properties. The increase of the glazed area as well as the integration of additional function into the glazing causes an increase of the total car weight, resulting in higher fuel consumption and therefore disadvantages concerning environment and resources. The substitution of ceramic glass by more lightweight transparent polymer materials like polycarbonate is a way to reduce the total weight of the car. As the resistance of polycarbonate against mechanical and chemical attack is limited, the surface must be protected by a transparent coating, for example based on silicon dioxide. Plasmapolymerization is a process well suited for the deposition of such coatings. This paper shows the state of the art of automotive glazing, describes innovative means for improving the surface properties of polycarbonate and demonstrates the potential of the process for the protection of searchlight lenses.     

Simulation einer flexiblen Montageanlage mit Simulationssystemen unterchiedlicher Konzeption

Zusammenfassung An einer flexiblen Montageanlage werden zur Simulation der logischen Abl?ufe mehrere Simulationssysteme eingesetzt, die auf unterschiedlichen Konzepten beruhen. Ihr prinzipieller Aufbau sowie die je nach Konzept verschiedenen M?glichkeiten der Modellbildung und Simulation werden anhand dieses Einsatzfalles untersucht.     

p‐TCOs für Transparente Elektronik

p‐type TCOs for use in transparent electronics In this article, a new type of semiconducting material is introduced. Transparent conducting thin films are already established in our everydaylife. But the type of these so‐called ?TCOs”? is dominated by electron transport, that means they are n‐type. To get transparent p‐n‐junctions and therefore transparent electronics, the missing part is a transparent p‐type material. Researchers all over the world have found different approach to produce this new generation of materials. At the Fraunhofer Institute for Surface Engineering and Thin Films (IST) in Braunschweig it is now possible to produce these kind of thin films as well.     

Barriereschichten für medizinische elektronische Implantate. Barrier coatings for medical electronic implants

The increasing relevance of active electronic implants for medical surgery and the progress in encapsulation technology open a new field of applications for high quality coatings in order to remove expensive and damageable ceramic housings. This article intends to show a possible way to create an organic‐inorganic coating system based on a highly filled polymer film in combination with an inorganic barrier layer.     

Transparente und leitfähige Veredelung von Kunststoffoberflächen

Deposition Techniques for Transparent Conducting Thin‐Films on Glass and Polymer Substrates We report on thin films deposited at atmospheric pressures on glass and polymer substrates with various techniques. The introduced thin‐film materials show intrinsic properties being suitable for different applications while maintaining the principle properties of the substrates themselves (e. g. shape. rigidity/flexibility, transparency). With the main focus on optical and electronic applications the properties of the deposited films can be adjusted by the choice of coating material (e. g. metal oxide, CNT), the film's shape (compact, particulate) and the deposition process itself. We compare deposition and properties of different TCO‐materials with CNT‐based thin film techniques and demonstrate approaches for the integration of these processes in production lines.     

Plasma‐aktivierte Bedampfung von flexiblen Materialien. Plasma‐activated vapour deposition on flexible substrates

The vacuum coating of flexible materials such as plastic webs is being used worldwide to change the surface properties for specific applications. The physical properties of interest e.g. density, hardness, refractive index and permeation are influenced by the microstructure of the coated layer. This paper describes, that this microstructure can be improved significantly by plasma enhanced evaporation techniques. At Fraunhofer Institute for Electron Beam and Plasma Technology (FEP), a method for plasma‐activated high rate deposition has been developed. This method is based on a hollow cathode arc discharge. This plasma‐source can be used for high productive roll coaters with boat evaporators or electron beam evaporators.     

Hauchvergoldung auf Relaiskontakten

Gold Flashing on Relay Contacts. It is not the colour but the resistance of contacts which determines their efficiency. Since, however, it is an expensive and time-wasting procedure to measure the resistance of every contact, many costomers reject relays whose silver contacts show a brownish-black discolouration, complaining that they have been kept too long in stock. This problem was believed to have been solved by the introduction of gold-flashing as a temporary coating while the contacts are kept in stock. Now the German Post Office's Telecommunications Head Quarters (Fernmeldetechnisches Zentralamt der Deutschen Bundespost) in Darmstadt have found indications which raise some suspecions as to the damaging side-effects of gold-flashing. For this reason, a working committee of the VDE (Association of German Electrical Engineers), group 1.6?Contact behaviour and switching processes”?, undertook its own investigations. The results were revealed during a platform-discussion on the 3rd October, 1973 in the Technical College at Karlsruhe and are given here in the form of edited speeches and a summary of the discussion.     

Bahnkorrektur auf Ellipsenbahnen

Forschung im Ingenieurwesen - Mit Hilfe der erweiterten Hillschen Gleichungen für Ellipsenbahnen mit kleiner Exzentrizität wird eine Methode zur Bahnkorrektur von Satelliten angegeben. Zu...     

Hochreflektierende Beschichtungen auf Kunststoffoptiken

Metallized polymer substrates offering highest reflectance are not yet state of the art. Coating organic substrate materials is still a task that is connected with multiple problems. Insufficient adhesion of coatings on polymer substrates represents one of the main difficulties. We could show by experiment that aluminium and silver layers indicate good coating adhesion on many different polymers if they are deposited by vacuum evaporation considering certain process parameters. High reflectance values and a good climatic stability of the metal coated polymer parts are other important challenges to plastic mirrors. By performing roughness measurements on the different polymer samples and by comparing reflection values obtained after coating these samples the impact of the polymers surface quality on the reflectance after metal coating has been investigated. Particularly high reflectance above 97% was realized with a protected silver mirror as well as with dielectric enhanced aluminium. Applying these layer systems excellent reflection properties has been obtained on several plastic substrates comparable to those on glass mirrors. Furthermore the dielectric layers used for reflection enhancement showed the ability to protect the aluminium coating against climatic influences.