My main goal was to apply and learn advanced interferometric methods such as computational shear interferometry (CoSI) and adaptive wavefront sensing for precise evaluation of lens quality and safety. Throughout my stay, I was able to take part in practical experiments, data processing, and discussions about computational phase analysis. The work environment at BIAS was highly supportive, and I was inspired by the expertise and enthusiasm of the research team.

This experience not only deepened my understanding of optical interferometry but also strengthened my confidence as a young researcher. I am deeply and sincerely grateful to MAPEX, Dr. Falldorf, Dr. Mostafa Agour and the entire BIAS team for their generous guidance, scientific support, and warm hospitality throughout my stay in Bremen. I also greatly appreciate the financial support provided by the MAPEX Center for Materials and Processes, which made it possible to achieve results that would not have been attainable elsewhere, meet wonderful people, and enjoy a memorable scientific exchange. I sincerely hope that this inspiring experience will lead to ongoing collaboration between our groups.

OECT-based complementary inverters are of particular interest due to their unique response to ionic environments, making them strong candidates for interfacing with and mimicking biological systems. For this reason, they have mainly been employed as ionic sensors and as amplifiers in neuromorphic circuits, where the key goals are high sensitivity, large voltage gain, fast switching speed, and longterm stability. In this project, we expanded an ongoing study focused on achieving long-term stability and fast switching speeds while maintaining good voltage gain in these inverters.

My stay at IMSAS and the University of Bremen allowed me to expand my knowledge and gain valuable experience with the vertical architecture of OECTs. This opportunity was fundamental for both my professional development and my personal growth, as I was able to immerse myself in the stimulating and supportive environment of IMSAS and Uni-Bremen. I would like to extend my sincere gratitude to Prof. Dr.-Ing. Björn Lüssem and everyone at IMSAS.

I am also deeply grateful to MAPEX for the financial support that made my stay possible. In particular, I would like to thank Dr. Hanna Lührs and Ms. Britta Hinz for their kind support throughout this period.

As part of the MAPEX PhD Research Grant, I had the privilege of conducting a one-month research stay at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) in Bremen, under the mentorship of Dr. Katharina Koschek. My project focused on the development of polysiloxane–benzoxazine imine-linked vitrimer composites designed for reprocessability, shape recovery, and carbon fiber reinforcement.

During my stay, I engaged in hands-on fabrication of high-performance polymer matrices using sustainable materials and dynamic covalent chemistry principles. The composite matrices were reinforced using both recycled and multidirectional carbon fibers through hand lay-up and compression moulding techniques. These processing techniques were crucial to enhance the mechanical properties of the otherwise soft polymer films, allowing us to prepare reprocessable, self-healing composites with improved thermal and structural performance.

Working alongside experienced researchers and PhD students, I benefited from interdisciplinary discussions and practical training on advanced composite manufacturing and characterization methods. This collaborative and stimulating environment helped me refine my experimental protocols and gain insights into the industrial viability of dynamic polymer networks, including solvent-assisted recyclability and carbon fiber recovery from the vitrimer matrix.

This research stay has not only contributed valuable experimental data to my doctoral thesis but also laid the foundation for future collaborative projects between my home institution and Fraunhofer IFAM. I also had great time exploring city culture of Germans. I am deeply grateful to the MAPEX Center for Materials and Processes for financially supporting this opportunity, which significantly enriched my research capabilities and broadened my professional network.

The research focused on exploring the potential application of organic electrochemical transistors (OECTs) as sensors due to their particular operation in liquid media. The primary goal was to detect the presence of clenbuterol, an anabolic agent used to increase muscle mass in cattle which possess serious health risks to humans consuming contaminated meat.

During the stay, the geometric factors of the device were varied and its response was studied, which allowed us to identify the ideal architecture for enhanced sensitivity. This also involved analyzing key performance metrics such as transconductance and hysteresis. Additionally, the concentration of clenbuterol was varied to determine detection limits, and to better understand the device’s behavior under varying analyte levels.

A comprehensive characterization of the device was achieved through techniques such as cyclic voltammetry and current-voltage measurements.

The devices with shorter channel lengths were found to have a higher on/off ratio and maximum transconductance values ​compared to those with longer channels. Furthermore, one specific device had a detection limit even below the maximum limit allowed by the World Health Organization (WHO-FAO) Codex Alimentarius which is very important for planned applications.

The results obtained from this research are planned to be published through a scientific article entitled “PEDOT:PSS organic electrochemical transistors (OECTs) as potential for clenbuterol detection in cattle”

Personally, I am convinced that this research stay significantly contributed to my professional and personal development. IMSAS provided me with all necessary tools to carry out my research, introduced me to new characterization techniques, and reinforced the importance of pursuing technological improvements aimed at the common good. I am deeply grateful to Prof. Dr. Björn Lüssem for welcoming me in his group and for his continuous support and guidance throughout my stay. I would like to thank Dr. Henrique Frulani and Dr. Andika Asyuda, whose insightful discussions were a key for achieving the results in the frame of this project. Furthermore, I sincerely thank all the researchers in the group for their assistance, support and for fostering a friendly and collaborative environment that made this experience truly enriching.

I would like to acknowledge MAPEX for funding this research stay. Without their support, this project would not have been possible. Beyond the academic results, I would like to highlight the personal growth this experience provided me.

Also, I would like to acknowledge the International Office of the University of Bremen for the complementary support. Particularly, thanks to Jana Sievers for all the assistance and guidance before and throughout my stay.

Finally, I would like to express my deepest gratitude to Prof. Dr. Jürgen Gutowski and Dr. Alejandra Castro-Carranza (my thesis supervisor and Research Ambassador of the University of Bremen for Mexico) for their unwavering support and guidance throughout this journey.

I would once again like to extend my gratitude to MAPEX for the funding, Dr. Hanna Lührs for her assistance through the process, my supervisors Prof. Sven Kerzenmacher, Dr. Guillaume Pillot, and Cyprien Verseux for their support, and Prof. Nils Averesch for warmly welcoming me in California.

During my stay we focused on the fabrication of biosensors. More specifically,field-effect transistors modified with enzymes (EnFETs) through a functionalization process (silanization and immobilization of enzymes) on AlGaN/GaN an GaN/AlGaN/GaN substrates. The fabrication of the EnFETs was carried out with the aim to analyze and understand the conduction mechanisms occurring in these devices, and therefore, to be able to suggest a model that can be used in future to improve their architecture. For this purpose, in addition to the electrical characterization measurements of the EnFETs, both atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to calculate and analyze the thickness of the functionalization layer on the surface of the transistors.

This experience has allowed me to learn and carry out experimental processes for the fabrication of biosensors, as well as to understand the electrical characteristics of these devices. Thanks to the outstanding results obtained, it will be possible for me to conclude my thesis successfully; and moreover, to promote the institutional cooperation with a joint scientific contribution, e.i, a publication.

I would like to thank Prof. Dr. Martin Eickhoff for enabling, supporting and trusting the ideas discussed in this project. I thank Genrietta Steingelb for her patience and support to teach me the biosensor manufacturing process. I thank Alexander Hinz for his time, help and support in the laboratory as well as the rest of the members of the Solid-State Materials Group for their hospitality.

I deeply thank MAPEX and the International Office of the Univ. of Bremen for giving me the opportunity to carry out this research stay in order to conclude the cooperation work initiated in June 2022. All this experience has been highly enriching for my personal and academic development.

I’m also very grateful to Dr. Alejandra Castro-Carranza for her time, guidance and support for the preparation of this proposal and her connection with the Univ. of Bremen as Research Ambassador for Mexico. Particularly, for her recommendation of my profile to the IFP, thanks to which all of this has been possible.

Last but not least, I deeply thank Prof. Dr. Jürgen Gutowski for his guidance and advice during my research stay.

Personally, this research stay has allowed me to learn a lot about computational molecular systems, and to gain experience to continue our joint work exploring different interfaces based on semiconductor oxides and other pollutants for sensing applications. This, in the framework of the Bremen-Mexican Network for the Development of Sustainable Technology for Environmental Apps. (bremex-steaps.net).

I would like to acknowledge the friendly working atmosphere at the HMI group, whose members were always open to discussion and willing to help in whatever they knew, as well as to explain the different theoretical parameters that became complicated in the simulations. Particularly, I would like to thank Dr. Susan Köppen and Eric Macke for all their support in this project, and for the many fruitful discussions.

I gratefully thank MAPEX and International Office for giving me the opportunity to do this research stay at the University of Bremen which has added a great value to my personal and academic development.

Finally, I deeply acknowledge Prof. Dr. Jürgen Gutowski and Dr. Alejandra Castro-Carranza (thesis supervisor and Research Ambassador of the University of Bremen for Mexico) for their support, guidance in the preparation of this project, and the contact and initial recommendation to be hosted at the HMI group.

During my stay, I was exposed to the fundamental techniques of two-dimensional nonlinear optical simulation spectrum. I also had the opportunity to gain hands-on experience with the instrumentation and experimental processes involved in two-dimensional nonlinear spectroscopy, particularly focusing on infrared transmission two-dimensional surface-enhanced spectroscopy. In addition, I presented a report to Professor Martin Zanni's research group on the principles and phenomena related to one-dimensional linear spectroscopy. Engaging discussions ensued, covering topics such as two-dimensional twisted spectroscopy, surface-enhanced spectroscopy, and one-dimensional linear spectroscopy. These conversations were enriched by the valuable insights shared by Professor Martin Zanni and Mr. Matt Ryan.

Particularly noteworthy was the in-depth exploration of surface-enhanced spectroscopy in dimensionally distorted spectra and its potential correlation with simulation, setting the stage for potential future collaborations in this area.

My heartfelt gratitude goes to Professor Zanni, Matt, Kiera, Alexei, Shivani, and all the researchers in the group for their invaluable assistance and support during my time there. Collaborating and studying alongside you all has been an enriching experience.

I am also thankful for the financial support provided by MAPEX, which afforded me the opportunity to engage with other researchers and broaden the scope of my research.

Finally, I express profound appreciation to my doctoral supervisor, Professor Johannes Kiefer, for his unwavering support and for granting me the autonomy to explore my research interests freely. Your guidance has been instrumental, and I am deeply grateful for your assistance whenever I needed it. Thank you most sincerely.

I greatly appreciate the financial support from the MAPEX Center for Materials and Processes, allowing me to obtain results that I could not have generated in Bremen, meeting fantastic people and partly escaping the German winter.

Raman spectroscopy is widely used for the analysis of 2D materials. MXene is the largest known family of 2D metal carbides, nitrides, and carbonitrides, there have been only a few reports on the Raman vibrational modes of this family. This project provides a detailed Raman spectral analysis of the double transition metal MXenes and their heterostructures. We also study the effect of surface terminations, ion intercalations, and the formation of heterostructures on the Raman spectral modes. This study provides the fundamental basis to understand the structure of these layered materials. This also provides an insight into how Raman spectra can be utilized for the characterization of the 2D MXene family specifically DTMs (double transition metal).

I am thankful to MAPEX for the financial support and for providing me with this opportunity where I had a chance to learn from the most insightful and cooperative supervisor Dr. Murshed from whom I have learned the theoretical and experimental fundamentals of Raman spectroscopy. I also want to extend my thanks Dr. Gesing for his support in research and informal discussions on personal development and professional growth. I appreciate my group mates Imran and Carla for helping me out with the characterization and analysis. I also want to thank Christopher for his help in the SEM characterization of the prepared samples. I appreciate all the members of CKfS groups for their support and cooperation.

I would like to extend my gratitude to Dr. Hanna Lührs for all the administrative support throughout this journey by making this process easy and smooth. This opportunity was an enriching experience for my personal and academic development.

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In this project, I have prepared up to seven samples of LMO with varying concentrations of Aluminum doping (1 to 5%). I have worked for single and double-flame pyrolysis. To evaluate the structure and properties of prepared samples, we have used X-ray Diffraction Spectroscopy and Raman Spectroscopy. Further, the bandgap of samples has been measured by using UV-Visible Spectroscopy. The pore size and surface area of the nanoparticles have been measured using BET. During my short stay at Uni-Bremen, I have hands-on experience working with flame spray pyrolysis. It was very useful to understand the concepts of basic characterization techniques through experienced guidance and hands-on working opportunities. With this experience, I have to build a strong foundation for my future research projects.

I am grateful to Professor Lutz Mädler and Dr. Suman Pokhrel for their assistance and support to complete my stay at Uni-Bremen. I would like to thank Ph.D. Scholar Jakob Stahl and bachelor student Tim Klotz for their support in carrying out experiments and characterization techniques. I am thankful to my friend Syeda Afsheen Zehra for sharing this exchange opportunity and helping me throughout the process.

I am thankful to MAPEX for the financial support and opportunity to work and gain experience in one of the most prestigious departments. It is not only an addition to my international work experience but also my personality development.

Finally, I would like to acknowledge the support of my MS thesis Supervisor Dr. Ghulam Ali from USPCAS-E, NUST for his supervision and help that enabled me to get this opportunity.

Paulina Abril Villagómez Mondragón from International Laboratory of Environment Electron Devices (LAIDEA) visiting Prof. Callsen/Prof. Gutowski (FB1, Solid State Physics, Semiconductor Optics)

My research stay at the University of Bremen from June 3 to August 12 in the group of Prof. Callsen/Prof. Gutowski, Semiconductor Optics, Inst. of Solid State Physcis, FB1, was focused on studying the photoluminescence and photocatalytic activity of GaN and InGaN nanowires to degrade a highly used dye and a medicament.

For this purpose, photoluminescence (PL) spectroscopy was carried out on the GaN and InGaN nanowire samples, using a HeCd laser as an excitation light source, while the morphology of the samples was characterized by scanning electron microscopy (SEM). To evaluate the photocatalytic activity of the samples for the pyrromethene 567 dye under UV illumination, a setup based on the infrastructure of the Institute of Solid-State Physics was built.

This experience has allowed me to discuss and learn from the optical spectroscopy and semiconductor experts as well as to understand the theoretical and experimental fundamentals of specific techniques such as Raman and PL spectroscopy. With this experience, I have further explored a very potential application of GaN as an exciting material to address an environmental and technological need of global interest, i.e., the degradation of pollutants in water.

I would like to thank Prof. Dr. Gordon Callsen and Prof. Dr. Jürgen Gutowski for enabling and supporting this project in the Semiconductor Optics Group, and for the many fruitful discussions. I thank Prof. Dr. Martin Eickhoff for passing the GaN and InGaN nanowire samples to carry out the experiments.

I deeply thank MAPEX for giving me the opportunity to do this research stay at the University of Bremen since it was an enriching experience for my personal and academic development. I acknowledge further a partial support by the International Office of U Bremen.

Finally I acknowledge support by Dr. A. Castro-Carranza based on her connection with the University of Bremen and the IFP as a Research Ambassador for Mexico and her guidance in the preparation of this project.

I believe that during my stay the experience and knowledge that I gained here will surely be very helpful for my future research work. I successfully applied for a PhD position in the Stauch group. I am very grateful to MAPEX for such a great opportunity for early researchers, enabling my stay in the group of Prof. Dr.  Tim Stauch at University of Bremen. I am thankful to Prof. Dr. Tim Stauch for giving me such an opportunity and further fruitful discussions during my stay.

It is also worth stressing that joint research projects are already in course, where the exchange of students and researchers between Federal University of Rio de Janeiro and Bremen University will be particularly important to strengthen the established partnership.

I’m very grateful for doing this research with Prof. Dr. Edwin Zondervan and his group. I had the opportunity to discuss and make progress on my thesis. Also I had the opportunity to improve myself, my knowledge, meet new people and new cultures. I recommend everyone to have a similar experience.

Multi-objective optimization of CCUS supply chains for the European countries with higher carbon dioxide emissions

Abstract

Global carbon dioxide emissions have increased in the last years to achieve a value of 33.1 Gt in 2018 and a concentration of 395 ppmv (IEA, 2019; Goel et al., 2015). With higher carbon dioxide concentrations there is an increase of global average temperature that, however, should be limited to 2 °C, as defined in the Paris agreement (Agrali et al., 2018). To achieve this important objective carbon capture utilization and storage (CCUS) supply chains have a strategic role and can be considered as a bridge for the development of more environment-friendly processes and for the reduction of carbon dioxide emissions.

Due to this important task, many mathematical models are developed in literature to design these systems through the single optimization. Generally, an economic objective function is considered while the target for carbon dioxide emission reduction is set as a constraint in the considered model (Hasan et al., 2013, 2014, 2015; Zhang et al., 2018; Sun and Chen, 2017; Leonzio et al., 2019a,b; Leonzio and Zondervan, 2019). Only the work of Yue and You (2015) considers simultaneously the economic and environmental objective functions of a CCUS supply chain (producing algae for biofuels), solved using the Life Cycle Optimization framework. Then there is a lack regarding the application of multi objective optimization problems to CCUS supply chains not producing only algae.

According to this considerations the novelty of this research work is evident: our previous single optimization problems developed for Italy, Germany and the UK (European countries with higher carbon dioxide emissions) are re-formulated as multi objective problems minimizing the total costs and maximizing the amount of capture carbon dioxide simultaneously. For the resolution the ε constraint and the augmented ε constraint methods are applied and compared, showing the best efficiency for the last one.

Overall, the analysis of the respective Pareto fronts shows that the CCUS supply chain for Germany is closer to the Utopia condition than the other two systems. A better tradeoff between the two objective functions is then achieved in the model describing the CCUS supply chain of Germany, even if the system has the highest costs.

References

Agralı S., Üçtug F.G., Türkmen B.A., An optimization model for carbon capture & storage/utilization vs. carbon trading: A case study of fossil-fired power plants in Turkey, Journal of Environmental Management 215 (2018) 305-315.

Goel C., Bhunia H., Bajpai P.K., Development of nitrogen enriched nanostructured carbon adsorbents for CO2 capture. J. Environ. Manag. 162 (2015) 20-29.

IEA (International Energy Agency), 2019. Global energy & CO2 status report. www.iea.org/geco/emissions/.

Hasan M.M.F., Boukouvala F., First E.L., Floudas C.A., Nationwide, regional and statewide CO2 capture, utilization and sequestration supply chain network optimization. Industrial & Engineering Chemistry Research, 53 (18) (2014) 7489–7506.

Hasan M.M.F, Boukouvala F, Floudas CA, Optimization of CO2 Capture, Utilization and Sequestration (CCUS) Supply Chain Networks, AIChE Annual Meeting in San Fransisco November 08, 2013.

Hasan M.M.F., First E.L., Boukouvala F., Floudas C.A., A multi-scale framework for CO2 capture, utilization, and sequestration: CCUS and CCU, Computers and Chemical Engineering 81 (2015) 2–21.

Leonzio G., Bogle D., Foscolo P.U., Optimization of CCUS supply chains in the UK: a strategic role for emissions reduction, 2019b, Chemical Engineering Research and Design, under review.

Leonzio G., Zondervan E., Analysis and optimization of carbon supply chain integrated by power to gas process in Italy, 2019, under review.

Leonzio G., Foscolo PU, Zondervan E., Sustainable utilization and storage of carbon dioxide: Analysis and design of an innovative supply chain, Computers & Chemical Engineering, 131, (5) (2019a), 106569.

Sun L., Chen W., Development and application of a multi-stage CCUS source–sink matching model, Applied Energy 185 (2017) 1424–1432

Zhang S., Liu L., Zhang L., Zhuang Y., Du J., An optimization model for carbon capture utilization and storage supply chain: A case study in Northeastern China, Applied Energy 231 (2018) 194–206.

My home research group led by Prof. Dr. Mendive in Argentina, is now working in the synthesis of several Metal Organic Framework (MOF) structures which have the potentiality for applications in the field of photoprotection, environmental treatment, and drug delivery, among others. In particular, I am working in the synthesis of new Bio-MOF structures, which consist of natural organic precursors. The main objective of my stay in Bremen was the characterization of the samples synthesized in Argentina, using both together: gallic acid and oxalic acid, named GAOX-MOF, and the comparison to already known Bio-MOF of gallic acid, named GAL-MOF. This represents an important contribution to my Diploma Thesis at the National University of Mar del Plata in Argentina, focused on the synthesis and characterization of Bio-Metalorganic Structures.

2. Description of the stay
The samples prepared in Argentina were characterized in Bremen by Temperature Gravimetric
analysis (TGA), Fourier Transformed Infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and XRay
Diffraction (XRD). It was very useful to have the chance to carry out these instrumental
measurements, since I could learn, not only about the preparation of the samples, but also
about specific issues related to every technique.

3. Perspectives
The research stay was very productive and fruitful since it was possible to characterize the described materials, and also for my formation in sciences by learning new techniques, methodologies, and procedures which are part of the expertise of the research group in Bremen.
The stay at the German group was also more than useful by learning about solids and their properties, an area which is not so well know for the students of my University.
The infrastructure and organization of the group led by Prof. Gesing not only made the stay very productive but was also educative and enjoyable. New contacts with the members from the German group were created, and further collaborative work and knowledge will surely follow this stay.

Abstract and Intermediate Report

ABSTRACT

In order to successfully conclude my thesis supervised by Dr. J. C. Nolasco and Dr. A. Castro-Carranza with outstanding results, the general goal of this short research stay at Prof. Gutowski’s Semiconductor Optics research group, Institute of Solid State Physics, is to carry out optical and electrical characterization of samples based on CuO and ZnO deposited on indium tin oxide (ITO) substrates for solar cell applications. All the studied samples have been fabricated in Mexico and they consist of: (i) heterojunctions formed by PCBM/CuO bilayers and contacted by Ag electrodes; and (ii) ZnO nanowires grown by wet-chemical deposition. Additionally, thin films of polystyrene have been deposited on some samples as interlayers to analyze the charge recombination rate at the heterojunction interface in our solar cell architectures. By applying optical and electrical characterization techniques, i.e, photoluminescence spectroscopy, photoconductivity, current-voltage and impedance spectroscopy, and circuit modeling, we aim to extract both the density of defect states and information about the charge transport mechanisms within the devices with different architectures. Once identifying the losses, we will define the optimal technological parameters to fabricate efficient low-cost solar cells based on these materials.

INTERMEDIATE MAPEX REPORT

Starting on September 9, 2019, I have been hosted by the Semiconductor Optics research group led by Prof. Dr. Jürgen Gutowski, Institute of Solid State Physics, Faculty of Physics and Electrical Engineering, University of Bremen, Germany, given the close cooperation between this group and my thesis supervisors Dr. Jairo C. Nolasco and Dr. Alejandra Castro-Carranza who is also Research Ambassador of the University of Bremen for Mexico.

The general goal of this short research stay has been to carry out optical and electrical characterization of samples based on CuO deposited on indium tin oxide (ITO) substrates for solar cell applications, that is complementing our research performed at ENES Morelia UNAM. The samples were fabricated in Mexico using a sustainable and low-cost chemical bath method, and they consist of heterojunctions formed by PCBM/CuO bilayers on ITO and contacted by Ag electrodes. Additionally, ZnO nanowire samples grown on ITO by wet-chemical deposition were fabricated in order to compare the performance of both types of devices. To tune the properties of the heterojunction's interface, besides modifying the CuO and ZnO chemical bath deposition parameters, some samples have been passivated by thin films of polystyrene as interlayers to avoid recombination in solar cell architectures.

Up to now, the following activities have been carried out:

- Preparation of the setup to measure impedance spectroscopy

- Electrical characterization of solar cells based on ZnO

- Thickness measurements of the CuO samples using profilometry in an atomic force microscope.

- Micro-photoluminescence characterization of CuO and ZnO samples

With these activities we have initiated the extraction of the defect density of states in our samples, and have obtained evidence that the passivation of the heterojunctions plays an important role to decrease recombination within the devices, and therefore to improve the efficiency of the solar cells.

Discussions of the results obtained in Bremen and Morelia have generated a fruitful environment with members of the Semiconductor Optics group, specifically with Prof. Dr. Gutowski, Dr. Alexander Kothe and M. Sc. Wilken Seemann who have supervised the activities in the laboratories. As for the Mexican part contributing to the discussions and results, besides Dr. Nolasco, the student Andres Castro Chacón co-funded by UNAM, Mexico, has been part of this enriching experience. In addition, I would like to mention that we are the first students of ENES Morelia UNAM coming to the University of Bremen in the framework of the cooperation agreement (CM-CSAM-UJ-CV-I-06-026/2018) signed in November 2018 by directives of the Faculty of Physics and Electrical Engineering (FB1) and ENES Morelia UNAM. . I hope that my stay here can foster an intensive collaboration between both Universities, including the mobility of more students in the near future.

I gratefully thank the University of Bremen and the MAPEX Center for Materials and Processes for giving me the opportunity to carry out this research stay that is adding a great value to my professional and personal development.

During my stay in the group, I gained an insight about optical characterization techniques, i.e., time resolved photoluminescence, which allows to understand fundamental recombination processes occurring in semiconductors. I also had the opportunity to share some knowledge about impedance spectroscopy to some colleges of the group. Impedance spectroscopy technique can be used to determine charge-carrier trap states that promote recombination at interfaces and at the bulk of the materials forming heterojunctions. The fruitful results of this stay are being prepared for publication.

I would like to highlight that this time in Bremen contributed significantly to consolidate my collaboration with the group of Prof. Dr. Jürgen Gutowski and with other members of the Faculty of Physics and Electrical Engineering. It is particularly important for my new position as Junior Professor of Veracruz University, Mexico, since we have defined guidelines for future joint research projects which also involve mobility of students and researchers to and from Mexico. All together, this is part of an initiative of Dr. Alejandra Castro-Carranza, Research Ambassador of the University of Bremen for Mexico, to form a scientific network conformed by members of the University of Bremen and of potential Mexican universities to develop jointly low-cost technology for sustainable applications, e.g., clean energy and detection of pollutants in the environment. See www.bremex-steaps.net/. 

Last but not least, I am also very grateful to my host, Prof. Dr. Jürgen Gutowski, for his feedback and the fruitful discussions, and for letting me know more about German culture and hospitality.

I am Baris Demir, an early career researcher in Bernhardt Group at Australian Institute for Bioengineering and Nanotechnology (AIBN) at the University of Queensland (UQ). I have been hosted by Prof Lucio Colombi Ciacchi who is the head of Hybrid Materials Interfaces (HMI) Group at Faculty of Production Engineering. My role during this research visit is to develop a molecular-level computational protocol to investigate redox active solid polymer electrodes that will be used as electrodes in batteries. In long term, my visit will be an initiator for a research collaboration between the University of Queensland and University of Bremen.

During the first half of my visit at the HMI Group, I had the chance to be part of a collaborative research with experimental partners. Furthermore, I had the opportunity to attend Surf and Science Workshop in Sylt organised by Hamburg University of Technology and University of Bremen, which aimed to bring together researchers from these universities and enable them to share their research findings and discuss further research collaborations. The quality of the research presented by the participants was above standards. I also delivered a talk on the use of molecular dynamics simulations to elucidate the structure-property relationships in materials. I am pretty sure that the second half of my research visit here, at University of Bremen, will be as good as the first half.

The joint collaboration deals with the production of soft ferromagnetic powders and the subsequent powder consolidation. It is very challenging to produce amorphous iron-based powders based on commercial purity due to cooling rate limitations and kinetically related growth, leading to crystallization. These limitations require high cooling rates which cannot be realized with conventional gas atomization. Therefore, novel cooling strategies were developed during gas atomization to increase the heat transfer coefficient which resulted in higher cooling rates and finally in amorphous powders. The as-atomized amorphous powders were consolidated via Spark Plasma Sintering at Tohoku University and analyzed with respect to the magnetic properties. The substitution of traditional magnetic materials through amorphous soft ferromagnetic alloys would be a great contribution to meet the worldwide requirements of accelerated power consumption.

I am very grateful for the opportunity working with Professor Yodoshi and the research people I meet at Tohoku University. I had the chance to discuss my research with the leading experts in my scientific field which personally brought me a lot of scientific progress. I am also very thankful for Prof. Yodoshi’s patience conducting research together, as he was busy with his own research as well as teaching me about daily Japanese curiosities and amazing food. 

Image capture:

The image was taken in Tokyo while we did sightseeing in a park. End of March is the time where the cherry blossoms (“Sakura”) start to grow and blooms across the entire country (“Hanami” time). Japan is a “happy country” during Hanami time, as people flock to parks, gardens, riversides to drink, eat, and be merry underneath the flowers. 

I am very grateful to MAPEX for the great opportunity for my research stay in the group of Prof. Dr. Jens Falta at University of Bremen in Feb-March 2019. I am thankful to Prof. Dr. Jens Falta for giving me such an opportunity, also Dr. Jon-Olaf Krisponeit and Simon Fischer for helping me in research work and during my stay in university guest house.