Completed projects

iCampus (BMBF, 16ES1128K)

Innovation campus electronics and microsensing CottbusSubproject: Development of silcon-based optimized gas sensors for the specific control of industrial processes and for mass-production

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, CxHy) 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

Promotional institution:
Federal Ministry of Education and Research (BMBF)
in the framework of the programme "RPME-Initiativprojekte"

Keywords:
gas sensors, micro-structering, atomic layer deposition, metal oxides, transition metals

Flexible PEEM (MWFK, EFRE, 85044894)

Flexible photoelectron microscope to consolidate the infrastructure of materials research for the energy turnaround

Brief description:
The project focuses on the consolidation of the materials research infrastructure for innovative applications in microelectronics, sensorics, photovoltaics, sustainable mobility, integrated energy, and »Power to X to Power« technology.
To fulfill this, an existing photoemission electron microscope (PEEM) will be adapted. In particular, a powerful helium source, an enhanced detector with an extremely high signal-to-noise ratio, and main components for a gas dosing system will be purchased and installed at the PEEM system.
Thus, the functionality of the PEEM will be improved by the possibility to perform angle-resolved photoemission spectroscopy (AR-PES) as well as in-situ model studies of gas adsorption.

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

Duration:
26.08.2020 - 31.05.2022 (Grant period)
26.08.2020 - 30.09.2021 (Execution period)

Index of advancement:
85044894

Promotional institution:
Europaen Regional Development Fund (EFRE) in the management of the Ministery for Science, Research and Culture (MWFK)

Promotional programme:
"Promotion of infrastructure, research, development, and innovation in the framework of EFRE (InfraFEI)"
General Informationen about Europaen Regional Development Fund.

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

ALD of IGZO layers ( BMWi, ZIM, ZF4510602AG7)

ALD process development of ternary and quaternary thin layers for transparent conducting oxides Sub-project: Spectrsocopic characterization of IGZO layers

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.

Cooperation partner:
SENTECH Instruments GmbH
Schwarzschildstraße 2
12489 Berlin

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

Duration:
01.04.2018 – 15.02.2021

Index of advancement:
ZF4510602AG7

Promotional institution:
Federal Ministry for Economic Affairs and Energy in the framework of Central Innovation Programme for SMEs (ZIM)

Keywords:
Atomic layer deposition, transparent conducting oxides, IGZO

Tuning vanadium dioxide films (DFG, FL 548/11-1)

Tuning vanadium dioxide films by extreme straining Local investigations on transition phenomena and exotic phases

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)

Promotional institution:
German Research Foundation (DFG)

Keywords:
Vanadium oxide, LEEM, Strain

Oxygen Storage (FVV)

Oxygen Storage/ Thermo-physical modelling of oxygen storage in three-way catalysts

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 NOx, CO, and unburned hydrocarbons.
Materials providing OSC in TWC are ceria-zirconia solid solutions of type CexZr1-xO2-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

Promotional institution:
Forschungsvereinigung Verbrennungskraftmaschinen e.V. | Research Association for Combustion Engines

Keywords:
Three-way-catalyst, oxygen storage, emissions, cerium oxide, reaction kinetics, reaction equilibrium, simulation

Modeling of catalytic fixed bed reactors (BMWi, ZIM, ZF4510601ZG7)

Novel simulation tools for the modeling of catalytic fixed bed reactors Sub-project:Experimental verification of heterogeneous catalysis on the example of direct CO2 conversion to methan and methanol for the development of a simulation software

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.

Cooperation partner:
LOGE Deutschland GmbH
Burger Chaussee 25
03044 Cottbus

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

Duration:
01.04.2018 – 31.03.2020

Index of advancement:
ZF4510601ZG7

Promotional institution:
Federal Ministry for Economic Affairs and Energy in the framework of Central Innovation Programme for SMEs (ZIM)

Keywords:
heterogeneous catalysis, CO2 conversion, direct CO2 conversion from flue gas, methanation