Project part: Afterburner/Reformer Unit

Brief description:
The "Turbo Fuel Cell R&D" project comprises the development of a hybrid energy conversion unit consisting of a micro gas turbine (MGT) and a high temperature fuel cell (SOFC). The focus is on component development and system integration for the construction of a prototype. In the overall project, 10 chairs of BTU Cottbus-Senftenberg are working in cooperation with the Fraunhofer Institute IKTS.
In the Afterburner/Reformer subproject, a combined system of reformer and afterburner is being developed for energetically optimizing the heat balance. For the catalytic steam reforming of methane and water to hydrogen and carbon dioxide, a temperature level of approx. 1000°C has to be chosen for the use of nickel-based catalysts, which has to be achieved by afterburning the exhaust gas of SOFC and MGT. The dependence of educt gas composition and flow rate, temperature and pressure derived from the experiment are used as a basis for model development. In the next step, the model being developed will serve as the basis for the simulation of complex geometries of the afterburner/refomer unit.

Cooperation Partner:

• Lehrstuhl Thermodynamik/Thermische Verfahrenstechnik
  Brandenburg University of Technology Cottbus - Senftenberg
  Prof. Dr.-Ing. Fabian Mauß
  Siemens-Halske-Ring 8
  03046 Cottbus

• Lehrstuhl Verbrennungskraftmaschinen und Flugantriebe
  Brandenburg University of Technology Cottbus - Senftenberg
  Prof. Dr.-Ing. Heinz Peter Berg
  Siemens-Halske-Ring 14
  03046 Cottbus

• Fraunhofer Institute for Ceramic Technologies and Systems  IKTS
  Dr. Stefan Megel
  01277 Dresden

Duration:
01.01.2020 – 31.03.2023

Index of advancement:
03EWS002A

Further information:

• TFC hompage

Keywords:
Ellipsometry, quadrupole mass spectrometry (QMS), low-energy electron diffraction (LEED), atomic layer deposition (ALD), physical vapor deposition (PVD)

Brief description

Motivation
Universities are a key innovation factor in the research-intensive microelectronics sector. Research at the highest international level is to be made possible to a greater extent by investing in state-of-the-art equipment and facilities at universities. Twelve "Research Laboratories Microelectronics Germany" are to open up new research fields for the microelectronics of the future and train young scientists with state-of-the-art equipment. The "Research Laboratories Microelectronics Germany" network with each other and with external partners for better scientific exchange and stronger cooperation.

Aims and  Approach
The new facilities at ForLab FAMOS will be used to integrate new materials (the semiconductors GeSn and SiGeSn, oxides, two-dimensional materials and polymers) into a mature silicon platform. This integration of new materials is expected to result in innovative optoelectronic devices, in particular sensors and integrated light sources, for optical data transmission or biosensors. The ForLab FAMOS will thus bring the BTU Cottbus-Senftenberg also internationally on top level in the research field of optoelectronic devices.

Innovations and Prospects
Electro-optical technologies can be used for faster and more energy-efficient data transmission, and optical biosensors can be configured specifically to desired applications. Potential applications range from rapid or on-site testing in emergency medicine (to detect sepsis) to self-monitoring (measuring hormone levels in saliva) and up to industrial process monitoring (such as food quality).

Cooperation Partner:

• Fachgebiet Experimentalphysik und Funktionale Materialien
  Brandenburg University of Technology Cottbus - Senftenberg
  Prof. Dr. rer. nat. habil. Inga Fischer
  Erich-Weinert-Straße 1
  03046 Cottbus

• Chair of General Electrical Engineering
  Brandenburg University of Technology Cottbus - Senftenberg
  Prof. Dr. rer. nat. Michael Beck
  Universitätsplatz 1
  01968 Senftenberg

Project manager:
Prof. Dr. Inga Fischer

Duration:
01.01.2019 – 31.12.2022

Index of advancement:
16ES0935

Brief description

The objective of this sub-work package is to demonstrate the functionality of sensors for the detection of hydrogen in laboratory experiments, and to determine the sensitivity and detection bandwidth at room temperature.
A resistivity-based gas sensor for the detection of small variations in gas composition in reductive environments (H₂, C_xH_y) with high sensitivity and low cross-sensitivity will be developed.
The already established concept of the change in conductivity of a metal oxide film under changing gas atmospheres is to be modified and optimized by a total of three approaches that are novel in their combination:

• Increasing the senosr sensitivity by scalable and reproducible nanostructuring of the silicon oxide substrate in a CMOS-compatible way
• Increasing the sensitivity through reproducible, tailored oxide film thickness reduction and conformal thin film deposition on patterned substrates using atomic layer deposition
• Optimization of the sensor selectivity for specific gas species by targeted chemical modifications of the oxide material

Cooperation Partner:

• Chair of Experimental Physics and functional Materials
  Brandenburg University of Technology Cottbus - Senftenberg
  Prof. Dr. rer. nat. habil. Inga Fischer
  Erich-Weinert-Straße 1
  03046 Cottbus

• IHP GmbH – Leibniz Institut für innovative Mikroelektronik
  Prof. Dr. rer. nat. habil. Christian Wenger
  Im Technologiepark 25
  15236 Frankfurt (Oder)

Project manager:
Prof. Dr. rer. nat. habil. Jan Ingo Flege

Duration:
15.11.2019 – 31.12.2021

Index of advancement:
16ES1128K

Further information:

• iCampus hompage
• BTU News press release

Keywords:
Photoemission Electron Microscopy (PEEM), Angle-resolved photoemission spectroscopy (AR-PES)

Brief description
The project focuses on the research and development of the atomic layer deposition (ALD) process of high-quality thin transparent conducting mixed oxides of the material class In-Ga-Zn-oxide (IGZO).
The quaternary IGZO material system is highly attractive for transparent electrodes in photovoltaics, LEDs, energy-efficient windows and in particular for thin film transistors in flexible or active matrix displays as well as for the low-cost paper electronic. For the fabrication of the oxidic thin films process and cost effective deposition techniques are required.
The usage of the ALD method for the deposition of thin IGZO layers offers one the one hand higher process controllability and on the other hand significant improvement of the layer homogeneity over large areas.
Firstly, the development of the ALD of IGZO layers will be based on investigations using existing systems and plasma sources to evaluate the principle functionality. In a next step, the new process system will be designed, constructed and built-up.
The layer homogeneity and the electronic and electrical properties of the deposited IGZO layers will be investigated.

Brief description
Vanadium dioxide is a correlated oxide with a metal-insulator transition at approximately 340 K. This transition is accompanied by a structural phase transition from the rutile metallic high-temperature structure to the monoclinic insulating low-temperature structure. The transition temperature can be tuned over a broad range by applying mechanical strain; also external electrical fields may drive the transition. Moreover, it is known that under mechanical straining further, exotic phases may occur. Consequently, vanadium dioxide exhibits a large potential for applications, e.g., in oxide electronics provided that these materials properties may be controlled and manipulated as thin films.
In this project we investigate simultaneously and in situ the growth and the structural and electronic properties of vanadium dioxide films on ruthenium dioxide surfaces of different orientations by low-energy electron microscopy (LEEM). We exploit the fact that oxidizing the ruthenium surfaces leads to the coexistence of different crystallographically oriented ruthenium dioxide islands that will act as templates in subsequent vanadia growth. The lattice mismatch between vanadia and ruthenia suggests the occurrence of differently and, in some cases, extremely strained vanadia depending on its orientation. Due to this extreme straining, we expect the occurrence of novel, exotic phases and, more generally, a considerably broadened tuning range for the transition temperature of vanadia. These phases will be thoroughly characterized by LEEM and related local diffraction and spectroscopy techniques, including synchrotron-assisted methods.
In a parallel effort, we aim to employ scanning probe microscopy to obtain unique insights into small-scale phase separation phenomena and also address, mindful of potential applications, the influence of applied electrical fields.
Furthermore, we will extend our studies to ruthenium thin films deposited on sapphire substrates by magnetron sputtering, thereby pushing for higher technological relevance.

Cooperation Partner:

• Dr. Jon-Olaf Krisponeit  
  University of Bremen
  Institute of Solid State Physics
  Surface Physics Group
  Otto-Hahn-Allee NW1
  D-28359 Bremen

Project manager:
Prof. Dr. rer. nat. habil. Jan Ingo Flege

Duration:
2017–2020

Index of advancement:
FL 548/11–1

Project number:
362536548 (GEPRIS)

Brief description
The oxygen storage capacity (OSC) in three-way catalysts (TWC) is directly linked to ceria-based materials. Their ability to store and release oxygen can buffer fluctuations in the exhaust stoichiometry. Thus, the stoichiometry of the exhaust gas can be kept within the small target air-to-fuel-ratio window (λ-window) around λ = 1 even when engine stoichiometry switches from lean to rich or vice versa. This is a desired requirement for a simultaneous conversion of the three pollutants NO_x, CO, and unburned hydrocarbons.
Materials providing OSC in TWC are ceria-zirconia solid solutions of type Ce_xZr_1-xO_2-δ (0<x<1). A detailed understanding of the thermodynamic properties of oxygen incorporation in these materials is important for optimization of the oxygen storage and release performance. The oxygen storage and release ability depends on the Ce/Zr ratio (the x-value), the amount of oxygen in the bulk (the δ-value) as well as the relative content of Ce⁴⁺ and Ce³⁺. The change in Gibbs free energy associated with storage or release of oxygen (∆G(δ)) and the change of Gibbs free energy due to changes of the Ce/Zr ratio (∆GS(x)) are distinguished properties of the oxygen storage material. Once those values are known, the equilibrium constants of all oxygen storage and release reactions can be directly derived. Experimental methods for doing so are based on measuring the equilibrium O₂ partial pressure.
The goal of the present project is to get a better understanding of how the equilibrium partial pressure of oxygen over oxygen storage materials can be measured and theoretically described. For that purpose, a series of tests on well-defined model-catalysts and industrial catalysts operated under idealized gas conditions as well as gas mixtures representing engine exhaust composition under realistic operation conditions will be performed. The knowledge gained will be incorporated into a model capable of depicting the dynamic behavior of a TWC. Said model can then be used for a better control of the TWCs performance and on-board diagnosis, benefitting car manufactures as well as engine control unit and catalyst supplies.

Project manager:
Prof. Dr. rer. nat. habil. Jan Ingo Flege (since 01.09.2018)

Duration:
01.07.2018 – 30.09.2020

Index of advancement:
6013150/ Oxygen-Storage M2816

Brief description
In the context of the energy transition, new and innovative concepts must be found for sustainable energy storage and supply with a simultaneous solution to the CO₂ problem. To meet the challenge of the fluctuating availability of renewable energies, the »power-to-gas« approach with a synthesis of methane on the one hand, but on the other hand also the »power-to-liquid« approach with a methanol synthesis are highly topical. Both processes are based on the use of heterogeneous catalysts, the performance of which plays a decisive role in the economic viability of the processes mentioned. If the catalytic reactions are understood, it is possible to optimize conversion, selectivity and yield while maximizing the life time.

The concept of a direct conversion of the CO₂ component from the flue gas of e.g. coal-fired power plants, refineries or the cement industry is investigated as a novel method in the project. The direct conversion has the advantage that the separation of the CO₂ is not necessary and e.g. methanol can be separated as a liquid phase. Methanation produces a gas mixture that can be converted back into electricity on demand in a combined heat and power plant. This would significantly expand the field of application for CO₂ conversion back into valuable substances such as methane or methanol.

Within the project, LOGE Deutschland GmbH is developing a software tool for modeling the physical processes and chemical reactions in the catalyst. The experimental data input and the verification of the modeling is performed by the Chair of Applied Physics and Semiconductor Spectroscopy at BTU Cottbus-Senftenberg. Based on the understanding of the underlying processes achieved in this way, the optimization and upscaling of the above-mentioned processes can succeed.