Annual Report 2019/20

Valued partners and esteemed readers,

Society was strongly influenced in 2019 by the commitment of young people to climate protection. By March 2019, several tens of thousands of scientists with the “Scientists for Future” association have also been supporting demands for climate and biosphere protection.

The Fraunhofer FEP has been working on sustainable products such as biodegradable electronics, environmentally friendly technologies for low-emission mobility, and seed treatment since well before this major public discourse. For decades, all our research activities have been focused on energy-efficient, forward-looking solutions as well as being oriented towards applications and industrial suitability.

The cover illustrates a milestone in the EU-funded project entitled “Accelerator Research and Innovation for European Science and Society” (ARIES): the first testing of a hybrid technology that removes oxides of nitrogen and sulfur as well as fine particulates from the exhaust gases of diesel-powered ships. Tests were carried out in summer on a ship in Riga (Latvia) using our system. The white smoke illustrates the success of exhaust gas scrubbing using low-energy electrons.

The Electron Beam division also achieved successes in its Coating Metal and Energy Technology department with the development of a non-toxic and efficient manufacturing process for porous silicon layers, which makes it possible to produce batteries with improved performance, higher charging capacity, and good charge/discharge cycling
stability over time.

In the Plasma Technology division, packaging films are increasingly being researched that meet aspects of sustainability. A framework agreement has been signed with an important company in the packaging sector.

The method of treating seeds with accelerated electrons, which has been established for over 20 years, was again in demand in 2019. It is an environmentally friendly process that effectively kills pathogens without the use of toxic chemical agents. The Fraunhofer FEP method, which is approved for organic farming as well, was further improved, enabling producers Ceravis AG to treat 18,000 tons of seed and BayWa AG 5,000 tons of seed.

A highlight in the field of microdisplays and sensor technology was the participation of Fraunhofer FEP in the Mobile World Congress in Barcelona, Spain. Together with LetinAR from South Korea, we debuted an ultra-light, power-saving, wireless module for data glasses that combines our OLED microdisplay with their unique optics.

In the Flexible Organic Electronics business unit, the EU-funded “PI-SCALE“ project was completed and the OLED pilot-line service created during this project came on-line under the name “LYTEUS”.

The “pro flex“ conference was held again in November. Over 20 international speakers presented talks on the wide range of options offered by roll-to-roll technologies for film and ultra-thin glass coating.

We would like to thank our customers, partners, and funding agencies for their support of our institute as well as for their trust and collaboration!

Project "KODOS"

In 2019, the Fraunhofer FEP began a collaborative project for the implementation of thin flexible glass in photonic applications. A total of nine partners in the project KODOS (Assembled Thin Glass Composite for Optoelectronic Systems) are working out the most favorable combinations of different manufacturing steps focusing on cost-effective and reliable processing of the glass.

The Fraunhofer FEP is contributing in particular its expertise in coating processes, but etching, lamination, and parting the glass also play important roles in the project. A strong focus will be on the deposition of transparent electrodes. In the case of this technology, the Fraunhofer FEP will build on preliminary work specifically intended to be developed for future applications.

As a result of the project, the consortium will be able to offer a complete kit of functional materials, semi-finished products, tools, and technologies. Demonstrators are planned for existing applications the automotive industry as well as in general lighting and for integrated decorative elements.

Project "PoSiBat"

The project entitled “Highly porous silicon-zinc coatings for batteries with very high energy density” (PoSiBat) was completed with great success in 2019. It involved investigations into the creation of highly porous silicon layers and their potential for manufacturing lithium-ion batteries with high energy density. Silicon-zinc layers were deposited by co-evaporation. Since silicon and zinc are immiscible in the solid state, a heterogeneous mixture of side-by-side silicon and zinc crystallites is formed during condensation. The size and distribution of the crystallites can be adjusted through the choice of process parameters. Zinc as the more volatile component was driven out of the layer matrix by means of sublimation using heat treatment in vacuum, thus creating porous silicon layers. Electrochemical studies in both the half-cell and full-cell configurations at the Fraunhofer Institute for Material and Beam Technology IWS showed initial charging capacities of more than 3000 mAh/gSi and comparatively good charge/discharge cycling stability over time. In addition, a design was also developed in the project for scaling the new technologies up for commercial production.

Project "ARIES"

„ARIES“ stands for „Accelerator Research and Innovation for European Science and Society“ and refers to a network of 42 European research institutions which, under the umbrella of the EU program HORIZON 2020 and coordinated by the European Organization for Nuclear Research CERN, are working in several project teams to explore and expand the innovation and application potentials of particle accelerators.

Within this framework, a field test conducted in the summer of 2019 at the Riga Shipyard under the leadership of the Technical University of Riga demonstrated that the exhaust gases from ship diesel engines, which are highly contaminated with pollutants (mainly sulphur and nitrogen oxides as well as particulate matter and partially burnt hydrocarbons), can be almost completely cleaned by a combination of electron beam treatment at atmospheric pressure and subsequent wet chemical gas scrubbing. This novel hybrid technology was developed by the Institute of Nuclear Chemistry and Technology Warsaw and has now been demonstrated for the first time on a large scale using a mobile electron treatment plant specially modified for this application by the Fraunhofer FEP. The electron sources used were two low-energy linear-type accelerators between which the exhaust gases of a tugboat were passed, converting the pollutants into water-soluble compounds with high energy efficiency. The process shall be scaled up in subsequent projects and tested in a real ship environment.

Innovative wear protection and new sintering process for printed electrodes

Titanium aluminum nitride coatings are used as wear protection on cutting tools because of their hardness and oxidation resistance. The coatings typically have an Al:Ti ratio < 2:1. In the project entitled „Investigation of technologies for the deposition of wear-reducing aluminum-rich TiAlN coatings“ (AlTiNTec), the ratio was increased further, which leads to a change in the microstructure. It was demonstrated that layer stacks with an increasing Al:Ti ratio > 3:1 can be deposited by means of magnetron sputtering. By forming a hard underlayer (40 GPa) and a softer top layer, they exhibit excellent cutting behaviour.

In the “New technological steps for high-efficiency solar cells” project (Neo-Sol), a new sintering process for printed electrical contacts on heterojunction solar cells was investigated. To achieve low electrical resistance as well as high efficiency, these electrodes are usually sintered in a furnace after printing. However, the solar cells may only be heated to a maximum of 200°C. Therefore, the electron beam was used to selectively sinter the printed contacts locally without heating the cells. Using conventional printing pastes, it could be shown that a result equivalent to sintering in a furnace can be achieved in a shorter time.

Project "TASG"

In the “Portable, self-sufficient and compact power generators“ project (TASG) launched in 2019, the Fraunhofer FEP is working on piezoelectric thin films for micro-energy harvesting. These will provide sensors with an autarkic energy source for self-sufficient operation, for example. The focus of the development is on sputter deposition of piezoelectric layers comprising aluminum nitride (AlN) and Scandium-doped AlN. It is challenging to simultaneous achieve of a high piezoelectric coefficient, excellent electrical insulation, and good adhesion to lifelike substrates such as stainless steel under high bending stresses. The thin-film approach should provide significantly lower costs compared to conventional bulk ceramic transducers, as well as providing lead-free components. Project partners are the Fraunhofer IIS, Wälzlagertechnik GmbH, H+E Produktentwicklung GmbH, and dresden elektronik ingenieurtechnik GmbH.

Project "SmartEEs"

The EU-funded “SmartEEs” project is working towards the establishment of a European innovation network that provides access to expertise, support for initially transferring innovative technology to companies, as well as for bringing it to commercial readiness. A Digital Innovation Hub (DIH) was created as a platform for this. This ecosystem consists of the technology services offered by technology providers, which are linked to services in the areas of product development, business support, and financial support.

3 of the 20 EU SmartEEs application projects were carried out by the Fraunhofer FEP. They dealt with the integration of OLEDs in wooden structures (project partners Woodoo SAS France and 3DMA) and with the combination of OLEDs and LEDs for human-centric lighting (project partner ESYST).

Though SmartEEs has expired, this attractive instrument for transferring research results into industrial prototypes as well as into commercial production will continue to be available to interested companies via the subsequent “SmartEEs2“ program beginning in 2020.

www.smartees.eu

Project "ADMONT"

Within the collaborative project “Advanced Distributed Pilot Line for More-than-Moore Technologies (ADMONT)” Fraunhofer FEP has realized a specifically designed OLED-on-Silicon backplane IC towards a sensor platform for optical excitation and read-out of sensing layers. There are two OLED dots as well as photodiodes and the control and readout electronics for emission and detection of light on the chips. The emission wavelength of the light emitting diodes can be adjusted in the visible and adjacent spectral range and thus enables the excitation of different sensor materials for different parameter measurements. By integrating color filters with adapted characteristics depending on the dye in the sensor layer, the sensor chip can be designed for a wide range of applications and combinations with sensor materials and is therefore versatile.

A sensor for measuring the oxygen concentration in gases is available as a technology demonstrator. Sensor layers specially developed at Fraunhofer FEP or commercial sensor spots can be used. A blue OLED excites the dye layer and the response phosphorescence signal is detected and evaluated in the CMOS backplane chip.

Longer service life for biological heart valve prostheses

A heart valve has to cope with a lot – it opens and closes about 2.6 billion times during a human lifetime! More than 30,000 people in Germany alone receive new heart valve implants every year. Degenerative changes are the main cause of heart valve diseases such as aortic valve stenosis.

There is a clear trend towards biological heart valve replacement in preference to the use of mechanical heart valves, since anticoagulant are often then not necessary. These biological prostheses are prepared from bovine pericardium or porcine heart valves, with long-term studies showing a 10-to-15-year service life. Causes for degeneration of these prostheses are mainly in the manufacturing process, which is why a new multi-component process, the SULEEI process, has been developed.

Decellularized pericardial tissue is simultaneously stabilized and sterilized by a low-energy electron-beam after UV cross-linking has been completed.

The application of this innovative tissue preparation process opens up the opportunity to develop new heart-valve prostheses having a level of durability never before achieved.

Project "Neptun"

In the project “Neptun”, we are continuing our long-standing and successful collaboration with CTF Solar GmbH to increase the efficiency of CdTe thin-film solar cells. The incorporation of selenium in the solar-absorber layer has simultaneously improved solar-cell quantum efficiencies in short as well as long wavelength regions. Glow discharge optical emission spectrometry (GD-OES) is an effective method for characterizing the selenium gradients in the absorber layers. In addition, GD-OES analyses are used to investigate low-level copper doping at the back electrode, which is necessary for low contact resistance.

The incorporation of selenium can influence the micro-structure of solar-cell absorber layers. This effect can be analyzed in crystal-orientation contrast with solar-cell cross-sections prepared using ion beams. Additional electron beam induced current measurements (EBIC) show the influence of the selenium gradient and the effect of chlorine activation on both the position of the pn junction and the diffusion length of the charge carriers.

Integrated package for the production of high-transparent barrier layers

During the 2019 financial year, the capability of the Division Systems was also demonstrated by the delivery of an AlOX processing system. This integrated package was specially developed for integration in an industrial roll-to-roll system of a well-known manufacturer of vacuum systems.

The Division Systems in cooperation with the Group Roll-To-Roll High-Rate Vacuum Coating supported the installation of the system into a commercial facility, its commissioning, and its initial run. The manufacturer is thus able to economically produce nearly non-absorptive barrier layers for mass-market packaging applications. In addition, it could be shown that this Fraunhofer FEP technology is also suitable for coating polypropylene and polyethylene films. This should make an important contribution in bringing sustainable packaging materials to the market in future.

Moreover, the Division Systems in collaboration with the Department Customized EB Systems and Technologies contributed importantly to the development and fabrication of a mobile experimental setup that empirically demonstrated effective operation of a novel treatment method for marine diesel engine exhaust as part of the EU ARIES project (Accelerator Research and Innovation for European Science and Society).