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Bachelor-/Masterprojekte

Sie interessieren sich für unsere Forschung? Das freut uns! Ob Sie nun lieber Solarzellen selber herstellen möchten, an Messaufbauten tüfteln oder physikalische Prozesse simulieren, wir finden bestimmt das Richtige. Für mögliche Themen für Bachelor-, Master-, oder Staatsexamensarbeiten sprechen Sie uns gerne an.

Mögliche Bachelor-Projekte:

  • Optimization of Interfaces in p-i-n Perovskite Solar Cells

    Project description

    This project focuses on optimizing the interfaces in p-i-n perovskite solar cells to enhance their efficiency and stability. Interfaces play a critical role in selective charge extraction, recombination processes, and overall device efficiency. The study involves identifying and testing suitable interfacial materials to improve charge extraction and minimize recombination losses, while also employing advanced deposition methods, such as atomic layer deposition (ALD) to create smooth, defect-free interfaces. You will produce perovskite solar cells and use advanced characterization techniques such as photoluminescence and current-voltage measurements to evaluate the performance of the interfaces. Additionally, modeling and simulation will help in understanding charge dynamics and optimizing energy band alignment. Furthermore, the impact of the interfaces on long-term stability will be assessed. This work aims to provide valuable insights into the role of interfaces in perovskite solar cells and propose strategies for improving their performance, contributing to the advancement of scalable and sustainable photovoltaic technology.

    Skills Acquired

    During this thesis, a variety of skills will be acquired, including expertise in understanding the properties and behavior of perovskite and interfacial materials used in solar cell fabrication. Hands-on experience with thin-film deposition methods such as spin coating, thermal evaporation, and sputtering will be gained, alongside proficiency in advanced characterization techniques like time resolved and absolutely calibrated photoluminescence, as well as current-voltage measurements for evaluating material and device performance. Data analysis and computational modeling will be applied to study charge dynamics and optimize interfaces. Problem-solving and project management skills will be developed through experimental design and troubleshooting, while scientific communication will be refined through writing and presenting findings. Collaboration in a multidisciplinary environment will enhance the ability to integrate materials science, physics, and engineering for innovative solutions.

      

     

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Mögliche Master-Projekte:

  • Fast current voltage measurement to characterize mobile ions in perovskite solar cells (bachelor or master thesis)

    Project description

    Perovskite solar cells are a highly promising technology for the next generation of solar cells. Due to their ionic crystal bonding character, metal halide perovskites differ from conventional , covalent bound solar cell materials like silicon or III-V semiconductors. As a result, mobile ions in perovskite solar cells lead to time-variant behavior like hysteresis, i.e. the solar cell “remembers” it’s pre-conditioning state. Ion migration can lead to performance loss and degradation. It is therefore of key importance to understand ion migration in these devices. 

    The goal of this research project is to develop measurement tools to analyze and understand the ionic nature of perovskite solar cells. Therefore, you will develop a “fast IV” measurement setup This tool enables to carry out current-voltage (I-V) scans whereby the scan speed is varied between 0.1 and 1,000 V/s. This will be carried out with the help of a function generator and digital oscilloscope. Additionally, a buffer amplifier needs to be added and shielding against electrical noise needs to be implemented.

    Aim

    You will set up a system for fast IV scans under simulated solar light. You will set the system in operation with perovskite cells variations. You will then use this method to assess performance losses and degradation mechanisms, using our maximum power point tracker based solar cell ageing station. 

    If you are perusing the project in the scope of a master thesis, you will also manufacture the perovskite solar cells yourself. Depending on how fast you progress is, you have the chance to establish complementary measurement techniques to assess ion migration such as bias assisted charge extraction (BACE) or Charge Extraction by Linearly Increasing Voltage (CELIV). 

    Skills acquired

    In this project, you can learn to set up an electrical measurement system comprising of function generators, oscilloscopes, amplifiers, and high-frequency shielding practices. You will get hands on experience with a wide range of opto-electric characterization techniques, starting from current-voltage measurements and extending to advanced techniques such as photoluminescence (PL) quantum yield, PL imaging, time resolved PL, as well as time resolved electrical techniques such as impedance spectroscopy etc.

    IN the scope of a master thesis, you will learn to fabricate, characterize and age your own perovskite solar cells.

    Moreover, you will acquire a profound understanding of ion migration and charge carrier dynamics in perovskite semiconductors.

    Further reading

    “Ion-induced field screening as a dominant factor in perovskite solar cell operational stability”. Thiesbrummel et al. Nature Energy (2024). DOI: 10.1038/s41560-024-01487-w

     

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