Projects

Photovoltaics, currently the cheapest and most efficient technology to convert solar light into electricity, are dominated by silicon wafer-based semiconductor technology. Thin film technologies, which can be deposited at low temperatures and at atmospheric conditions, promise to overcome the residual disadvantages of the silicon technology, such as the long processing time and expensive scale-up costs. However, the compositional and processing parameter range for novel thin film semiconductors is enormously broad and is driven by performance parameters like efficiency, lifetime, and costs. These factors make the time to market for novel semiconducting materials today ́s major challenge. In this project we will, therefore, combine specific aspects of robot-based synthesis methodologies with advanced characterization techniques to explore the parameter space of novel Pb-free perovskite semiconductors, allowing for the generation of a comprehensive database of perovskite semiconductors. The ultimate goal is to convert the most promising candidates into efficient single-junction or multi-junction devices or innovative layers for energy conversion.

The Energy Campus Nuremberg deals with energy technology of the future. The partners work on all relevant topics to make energy supply more flexible and sustainable. In the part addressing the long-time storage of energy the Chair of Energy Processing works on a new, innovative concept for methanation.

This new concept is optimized for dynamic operation in power-to-gas applications and is experimentally demonstrated.

Organic semiconductors have an enormous potential for renewable energy applications, in particular for green photovoltaic electricity production. However, the performance, processability and stability of the current state of the art organic semiconductors are not well balanced to yield performance and environmental stability within one set of materials. Most publications report on either stable or efficient material composites. Novel materials and, even more important, novel design rules for material classes overcoming the current losses need to be developed. Most importantly, these novel design rules need to better balance the performance of organic electronic devices with their materials- and processing-related microstructure induced degradation mechanisms. This proposal targets to develop novel materials classes allowing to tackle the known microstructure induced degradation losses, enable reliable processing and to combine performance and lifetime within one composite. This synergistic research effort between SCUT and FAU targets, for the first time, developing high performance and high stability materials hand in hand. Novel material classes will be efficiently screened and explored by a combination of in-situ and high throughput testing methods. The demonstration of organic photovoltaic devices with a PCE of over 12% and excellent operational lifetime of over 10 years (measured under accelerated conditions) is the final milestone of this project.                             

Die Liberalisierung des Energiemarktes sowie der zunehmende Ausbau erneuerbarer Energien stellen neue Anforderungen an unser Energiesystem im Hinblick auf den Ausbau von Netzen, die Produktion, Verteilung sowie zukunftsweisende Stromspeichertechnologien. Eine erfolgreiche Transformation hin zu einem „Smart Energy System" hängt dabei wesentlich von adäquaten Investitionsanreizen und der Attraktivität der Geschäftsmodelle der beteiligten Stakeholder ab. Im Rahmen des Forschungsprojekts „Sustainable Business Models in Energy Markets: Perspectives for the Implementation of Smart Energy Systems" sollen daher das Energiesystem und die Geschäftsmodelle der Beteiligten interdisziplinär analysiert werden. Ziele des Forschungsprojekts sind die Generierung von neuen und dringend erforderlichen Erkenntnissen zur Interaktion zwischen Geschäftsmodellen und Regulierung unter Berücksichtigung der technischen Referenzmodelle sowie die Ableitung von Empfehlungen für politische und regulatorische Rahmenbedingungen zur Sicherstellung einer erfolgreichen Transformation des Energiesystems.

Research into innovative nanostructured materials is of fundamental importance for Germany’s technological competitiveness and in addressing global challenges, like the development of renewable energy sources. Nanostructured materials are controlled by size and interfaces, which give rise to enhanced mechanical properties and new physical effects leading in turn to new functionalities. The design of novel nanostructured materials and devices such as flexible electronics demands state-of-the-art nanocharacterisation tools. In particular, methods based on short-wave radiation (electrons, X-rays/neutrons) or scanning probes are ideally suited to analyse materials at the nanometer and atomic scale. Recently developed in situ capabilities and the use of complementary characterisation methods allow unique insights into the structure formation, functionality and deformation behaviour of complex nanostructures. These new in situ techniques will be the future key tools for the development of new materials and devices. The doctoral programme combines, for the first time, these three pillars of nanocharacterisation into a structured Research Training Group. The main objective of this programme is to provide the next generation of scientists and engineers with comprehensive, method-spanning and interdisciplinary training in the application of cutting-edge nanocharacterisation tools to materials and device development. Within the programme, the in situ methods will be further developed and used to address fundamental questions regarding the growth, stability and functionality of complex nanostructures and interfaces. Project area A "Functional Nanostructures and Networks" will address the properties of individual nano-objects and how these translate into functionality when assembled to nano-networks. In Project area B "Mechanical Properties of Interfaces" various kinds of interfaces with different bonding characteristics and morphologies will be studied in well-defined loading scenarios. This parallel, complementary study of both functional and mechanical materials properties over several length scales by multiple in situ methods is unprecedented. Our PhD candidates will be well-positioned in a network of international collaborations and highly trained in multiple, complementary techniques, providing them with an essential foundation for a successful career in the field of advanced materials and devices development.

Project A6 combines the findings from the first funding period, which investigated the transport properties of metallic nanowires as well as inorganic nanoparticles as a function of microstructure and microstructure with c-AFM and electron microscopy methods. The follow-up project will address the electrical and optical properties of nanoparticle-filled nanowire composites. The focus of the investigations is on the microscopic understanding of the charge carrier transport between the semiconducting matrix and the metallically conductive nanowires. In situ X-ray spectroscopy under light (c-AFM and STM) should provide insight into the electrical processes at the interfaces.

Metal-organic charge-transfer complexes based on TCNQ shows exciting electrical or photochemical switching properties, which involves modification of the valence state of TCNQ (TCNQ-/TCNQ°). We use complementary microspectroscopic tools to investigate in-situ the switching behaviour of individual Ag-TCNQ nanocrystals. Structural probes like Nano-XRD and electron diffraction are considered to offer insight into potential structural modifications upon electrical switching.

The design and development of ternary bulk heterojunction (BHJ) composites requires the investigation of three separate aspects and fundamental topics of organic semiconductors and photovoltaics.1. Synthesis: The project will start with available polymers for the transport matrix as well as for the sensitizers, and then quickly move over to novel polymers, customized for the purpose of near IR sensitizing, i.e. with various bandgap and smaller variations in the HOMO position.2. Morphology: The morphology assessment and morphology control of ternary BHJ composites will be another challenge in this project. Polymers which are not completely miscible to each other (and that is the common situation) will show demixing in solution as well as in the solid state. Following Hildebrandt, polymers are miscible to each other if they have comparable intermolecular adhesion forces. Our access to understand and investigate the phase separation mechanisms in ternary systems will be based on an approach similar to Hansen theory. By assessing the solubility parameters for the individual components we investigate the Hansen sphere for a ternary composite.3. Transport and Charge Transfer: Transport in binary BHJ composites is already a complex process. Within this project we will investigate the transport mechanisms in ternary composites. Specifically, we will explore suitable experimental methods which allow to distinguish between the role of the two polymer and their individual contributions to the hole transport. As important as transport is the charge generation process in the ternary blends. Time resolved pump-probe spectroscopy in the ns regime will be used to understand how the two polymers interact with each other. Most importantly, we want to clarify whether the two polymers may show direct charge transfer, energy transfer, or even have no electronic interactions.