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Bachelor/Master projects
Are you interested in our research? That makes us happy! Whether you prefer to produce solar cells yourself, tinker with measurement setups or simulate physical processes, we are sure to find the right thing for you. Please contact us for possible topics for bachelor's, master's or state examination theses.
Bachelor/Master Projects:
Possible Bachelor/Master Projects
There are currently no thesis topics available. However, if you are interested in writing a thesis with us, please don’t hesitate to contact us. We’ll then work together to see if we have the capacity to supervise you and, if so, find a suitable topic!
Archive
In this archive, you will find topics that have been addressed in the past. Here, you can get an overview of the topics that previous graduates have already worked on in our working group.
Optimization of Narrow-Bandgap (NBG) Perovskite Solar Cells for Tandem Applications (Bachelor's Thesis)
Project Description
This project focuses on the optimization of narrow-bandgap (NBG) perovskite absorber layers for tandem solar cell applications. The goal is to fine-tune the composition, processing conditions, and post-treatment steps to obtain layers with suitable bandgaps (1.2–1.3 eV), high crystallinity, and low non-radiative recombination. You will fabricate NBG perovskite films and characterize them using UV-Vis spectroscopy with Tauc plot analysis to determine the optical bandgap, as well as PLQY and time-resolved photoluminescence to evaluate radiative efficiency and carrier lifetime. Morphology and phase purity will be evaluated using microscopy and X-ray techniques. Promising absorber layers will be integrated into complete solar cells, and the performance of the devices will be evaluated via JV scans, EQE measurements, and stability tests. Simulations and experimental studies on band alignment will be used to understand and optimize charge transport at the interfaces, with the aim of advancing the development of efficient, stable, and scalable NBG-perovskite solar cells for next-generation tandem photovoltaics.
Skills to be Acquired
You will acquire expertise in perovskite materials science, particularly in the synthesis and optimization of NBG absorber layers. You will develop practical skills in thin-film fabrication (e.g., spin coating, thermal annealing) as well as optical and electronic characterization techniques such as UV-Vis spectroscopy, Tauc plot analysis, PLQY, and time-resolved PL. You will also work with tools for device characterization such as JV and EQE and apply modeling techniques for analyzing band alignment. Throughout the project, you will improve your problem-solving, data analysis, and scientific communication skills and gain experience working in a multidisciplinary research environment that combines materials science, physics, and engineering.
Contact person (English-speaking): Gülüsüm BabayevaInterlayers for Stable All-Perovskite Tandem Solar Cells (Bachelor's/Master's)
Project Description
Tandem solar cells based entirely on perovskite absorbers are among the most promising next-generation photovoltaic technologies. By stacking an upper perovskite cell with a wide bandgap (for absorbing high-energy photons) on top of a lower perovskite cell with a narrow bandgap (for absorbing lower-energy photons), these devices can exceed the efficiency limit of single-junction solar cells and achieve theoretical efficiencies of up to 44%. A key challenge in the fabrication of monolithic (2-terminal) tandem solar cells is the integration of interlayers that electrically and optically connect the two subcells without compromising stability or performance. These interlayers must be chemically compatible, enable efficient charge recombination, and ideally support scalable fabrication. Our group is addressing this challenge by using vacuum-based sputtering techniques to deposit ultrathin and robust interlayers. To this end, we have acquired a new vacuum deposition system. As part of this project, you will help with the commissioning of the system and subsequently use it for the fabrication and optimization of tandem interlayers.
Main Responsibilities
- Assist with the commissioning of the new vacuum sputter coater, including calibration, troubleshooting, and establishing safe operating procedures.
- Develop and optimize sputtering protocols for various interlayer materials (e.g., metal oxides, recombination contacts, buffer layers).
- Integrating sputtered interlayers into all-perovskite tandem devices and evaluating their impact on performance and long-term stability.
- Collaborate with other team members in the fabrication and characterization of complete tandem solar cells.Skills to Be Acquired
By the end of the project, you will have gained valuable interdisciplinary experience at the intersection of materials science, photovoltaics, and vacuum technology, including in-depth knowledge of optoelectronic perovskite materials and interface engineering for tandem solar cells. In addition to practical knowledge in the operation and maintenance of vacuum deposition systems, particularly sputtering, you will have experience with a range of characterization techniques such as I-V (current-voltage) measurements, EQE (external quantum efficiency), ellipsometry, and hyperspectral photoluminescence imaging for spatially resolved material quality assessment. This will help you develop experimental routines and protocols for the reproducible fabrication of devices, thereby strengthening your scientific communication and presentation skills in a supportive, collaborative team environment.
Target Audience
This project is ideally suited for master’s students and motivated bachelor’s students in physics, chemistry, materials science, electrical engineering, or related fields. We are looking for highly motivated individuals who already have laboratory experience and enjoy working independently on experimental tasks. A strong interest in renewable energy and practical fabrication is essential. Previous experience with vacuum systems or thin-film deposition (e.g., spin coating, sputtering, vapor deposition) is a plus.
Start date: Summer 2025
Contact person: Christopher JanasOptimization of the Hole Transport Layer (HTL) to Improve Efficiency and Stability in Perovskite Solar Cells (Bachelor's/Master's)
Project Description
Perovskite solar cells (PSCs) have attracted significant attention in photovoltaic research due to their remarkable energy conversion efficiency and cost-effective fabrication processes. A critical component that affects the performance and stability of PSCs is the hole transport layer (HTL), which enables efficient charge extraction and transport while mitigating recombination losses at the interface. Conventional single-layer HTLs often exhibit limitations, such as suboptimal energy level alignment, insufficient moisture resistance, and thermal instability, which limit the overall efficiency and longevity of the device. To overcome these issues, the integration of bilayer HTLs has proven to be a promising strategy. By combining two complementary materials, this approach improves charge transport dynamics, optimizes the alignment of interface energy levels, and enhances the environmental and thermal stability of PSCs. Consequently, bilayer HTLs hold significant potential for improving the commercial viability and long-term operational stability of perovskite-based photovoltaic technologies.
The goal of this project is to investigate, optimize, and implement various hole transport layers (HTLs), including P3HT, NiOx, and PEDOT, within the structure of double-layer HTLs in perovskite solar cells. The goal is to improve both the power conversion efficiency (PCE) and the operational stability of these solar cells, thereby contributing to their overall performance and durability.
Skills to Be Acquired
In this project, you will gain hands-on experience in the fabrication of perovskite solar cells using solution-based processes. In addition, you will have the opportunity to apply a comprehensive range of optoelectronic characterization methods, ranging from basic current-voltage (I-V) measurements to advanced techniques such as photoluminescence quantum yield (PLQY), photoluminescence imaging (PL), and time-resolved PL (TRPL). Furthermore, you will evaluate the long-term stability of the fabricated devices using our specialized aging station, which provides valuable insights into their degradation mechanisms and operational lifespan.
Contact person (English-speaking): Ali Reza Nazari PourOptimization of Interfaces in p-i-n Perovskite Solar Cells (Bachelor's Thesis)
Project Description
This project focuses on optimizing the interfaces in p-i-n perovskite solar cells to improve their efficiency and stability. The interfaces play a crucial role in selective charge extraction, recombination processes, and the overall efficiency of the devices. As part of the study, suitable interface materials will be identified and tested to improve charge extraction and minimize recombination losses. In addition, advanced deposition methods such as atomic layer deposition (ALD) will be used to create smooth, defect-free interfaces. You will fabricate perovskite solar cells and apply advanced characterization techniques, such as photoluminescence and current-voltage measurements, to evaluate the performance of the interfaces. Furthermore, modeling and simulation will contribute to understanding charge dynamics and optimizing energy band alignment. Furthermore, the impact of interfaces on long-term stability will be evaluated. This work aims to provide valuable insights into the role of interfaces in perovskite solar cells and to propose strategies for improving their performance, thereby contributing to the further development of a scalable and sustainable photovoltaic technology.
Skills to Be Acquired
This work will allow you to acquire a wide range of skills, including knowledge of the properties and behavior of perovskites and interface materials used in the fabrication of solar cells. Practical experience will be gained with thin-film deposition methods such as spin coating, thermal evaporation, and sputtering, as well as knowledge of advanced characterization techniques such as time-resolved and absolutely calibrated photoluminescence and current-voltage measurements to evaluate material and device performance. Data analysis and computer-aided modeling are used to investigate charge dynamics and optimize interfaces. Problem-solving and project management skills are developed through experiment planning and troubleshooting, while scientific communication is refined through writing and presenting results. Collaboration in a multidisciplinary environment will enhance the ability to integrate materials science, physics, and engineering to develop innovative solutions.
Contact person (English-speaking): Gülüsüm BabayevaRapid Photoluminescence Voltage Measurement for Characterizing Mobile Ions in Perovskite Solar Cells (Bachelor’s or Master’s Thesis)
Project Description
Perovskite solar cells are a promising technology for the next generation of solar cells. Due to their ionic crystal bonds, metal halide perovskites differ from conventional, covalently bonded solar cell materials such as silicon or III-V semiconductors. As a result, mobile ions in perovskite solar cells lead to time-dependent behaviors such as hysteresis—that is, the solar cell “remembers” its previous state. Ion migration can lead to power losses and degradation. Therefore, it is crucial to understand ion migration in these devices.
The goal of this research project is to develop measurement tools for analyzing and understanding the ionic properties of perovskite solar cells. To this end, you will develop a “Fast-PL” measurement setup. This tool enables the performance of photoluminescence (PL)-voltage (PL-V) scans, with the scan speed varying between 0.1 and 1,000 V/s. This is achieved using an optical setup to measure PL intensity via a photomultiplier tube, a function generator, and a digital oscilloscope. Additionally, a buffer amplifier must be added, and shielding against electrical interference must be implemented.
Objective
You will set up a system for fast PL scans under simulated sunlight. You will commission the system using various perovskite cells. You will then use this method to evaluate power losses and degradation mechanisms, utilizing our solar cell aging station based on a maximum power point tracker.
If you are working on this project as part of a master’s thesis, you will also fabricate the perovskite solar cells yourself.Skills to Be Acquired
In this project, you will learn to set up an optoelectrical measurement system consisting of a photomultiplier tube, function generators, oscilloscopes, amplifiers, and high-frequency shielding. You will gain hands-on experience with a variety of complementary optoelectronic characterization techniques, ranging from current-voltage measurements to advanced techniques such as photoluminescence (PL) quantum yield, PL imaging, time-resolved PL, and more.
As part of a master’s thesis, you will learn to fabricate, characterize, and age your own perovskite solar cells.
In addition, you will gain a deep understanding of ion migration and charge carrier dynamics in perovskite semiconductors.Further Reading
(The references do not directly address the measurement instrument but provide an introduction to the topic.)
“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
“Intensity-Modulated Photoluminescence Spectroscopy for Revealing Ionic Processes in Halide Perovskites,” Gillespie et al. ACS Energy Letters (2025). DOI: 10.1021/acsenergylett.5c01102
Contact: Dr. Lukas WagnerDevelopment of an In-Situ Photoluminescence Imaging System (Bachelor's Thesis)
Project Description
Photoluminescence (PL) imaging is a powerful, non-contact technique for characterizing perovskite semiconductor films. It enables spatially resolved visualization of defects, thickness variations, and crystallization quality—parameters that are essential for optimizing high-performance perovskite solar cells. However, commercial PL imaging systems are typically very expensive, bulky, and often unsuitable for integration into gloveboxes where perovskite films are fabricated.
The goal of this project is to develop a compact, cost-effective PL imaging platform based on a Raspberry Pi NoIR camera sensor. The system will be tailored for in-situ, real-time monitoring of film formation during perovskite deposition using a spin-coating robot. To achieve this, you will design an excitation and detection module, evaluate the sensor’s performance, and implement an image processing workflow that enables quantitative PL mapping within a glovebox environment.
Objectives
• Characterize the spectral sensitivity and quantum efficiency of the Raspberry Pi NoIR sensor for PL detection.
• Design and build an optical system using LED excitation sources and high-performance bandpass filters.
• Integrate the imaging system into a glovebox mounted on a spin-coating robot for in-situ monitoring during perovskite film fabrication.
• Develop a software pipeline for real-time visualization and analysis of PL intensity and crystallization dynamics.Skills to be acquired
• Experience in the design and assembly of optical and electrical measurement systems, including optical excitation modules, optical filters, camera-based detectors, and their calibration.
• Hands-on skills in PL imaging and the characterization of semiconductor thin films, with a focus on perovskite materials.
• Programming experience in the areas of image acquisition, signal processing, and real-time data visualization (e.g., Python).
• Understanding of crystallization processes, defect formation, and structure-property relationships in metal halide perovskite semiconductors.
• Hands-on laboratory experience with glovebox-integrated measurement setups.Further Reading
(The references do not directly address the measurement instrument but provide an introduction to the topic.)
“Revealing fundamentals of charge extraction in photovoltaic devices through potentiostatic photoluminescence imaging”. L. Wagner et al. Matter (2022). DOI: 10.1016/j.matt.2022.05.024
Contact: Dr. Lukas WagnerManufacturing of Tandem Solar Cells (Master's Thesis)
Project Description
This thesis focuses on the optimization of a narrow-bandgap (NBG) perovskite solar cell and its integration into a tandem cell. Starting with an existing absorber, you will improve its optical and electrical performance through interface engineering and the development of a buffer layer.
The goal is to establish a reliable fabrication process for highly efficient perovskite tandem solar cells and to contribute to next-generation photovoltaic solutions.Main Tasks
• Fabrication of tandem solar cells
• Optimization of the NBG bottom cell
• Interface engineering and design of the buffer layer
• Integration of optimized layers into tandem stacks
• Optical and electrical characterization: JV, UV-Vis, PL, EQE…Methods and Tools
• Spin coating, Spinbot
• Sputtering, thermal evaporation, ALD (Atomic Layer Deposition)
• Glovebox processing and thin-film deposition
• Standard techniques for characterizing solar cellsPreferred Background
• Chemistry, physics, materials science, or related fields
• Experience with glovebox work and thin-film processing is an asset
• Motivation to work in a collaborative research team
Contact: Gülüsüm Babayeva (English-speaking)Development and Optimization of Carbon-Laminated Perovskite Solar Cells for Improved Efficiency and Stability (Bachelor's or Master's Thesis)
Project Description
Perovskite solar cells (PSCs) have considerable potential due to their high energy conversion efficiency, cost-effective processing, and compatibility with low-temperature solution-based fabrication. However, their economic viability remains limited by issues related to environmental and operational stability, as well as challenges associated with large-scale manufacturing.
Carbon-based bottom electrodes have emerged as a promising approach to overcoming these limitations. Unlike gold (Au) or silver (Ag) electrodes, which are expensive, require vacuum deposition, and can chemically interact with halide species in the perovskite, carbon electrodes offer intrinsic chemical inertness, significantly lower material costs, and compatibility with scalable techniques such as printing and lamination. These advantages make carbon electrodes strong candidates for improving both the stability and manufacturability of perovskite solar cells.Project Objective
This project aims to develop and optimize carbon-laminated PSC architectures that improve the efficiency and stability of the devices while enabling manufacturing processes suitable for scalable module production.
Main Objectives
1. Development of lamination techniques
• Establishment of lamination protocols compatible with perovskite layers and transport layers.
• Optimization of temperature, pressure, lamination duration, and pre- and post-treatments.
• Characterization of electrical conductivity, work function, and surface/interface properties.
2. Fabrication of carbon-laminated PSCs
• Fabrication of complete devices using laminated carbon electrodes.
• Evaluation of JV parameters, i.e., current density, open-circuit voltage, fill factor, series resistance, and reproducibility.
3. Interface engineering
• Modification of the interfaces between perovskite and carbon electrodes to improve the performance of solar cells.What Students Will Learn
By the end of this project, students will have acquired comprehensive knowledge of the fabrication and analysis of advanced photovoltaic devices. They will gain hands-on experience with the fabrication of perovskite solar cells, carbon lamination techniques, and the optimization of device interfaces. Through systematic experiments and characterizations—including JV measurements, optical and structural analyses, and surface/interface evaluations—students will learn how to correlate material properties with device performance and stability. They will also strengthen their skills in troubleshooting fabrication issues, designing experiments, and interpreting results. Overall, participants gain practical laboratory skills, a deeper understanding of perovskite photovoltaics, and valuable research competencies that are beneficial for both academic and industrial careers in the fields of renewable energy and materials science.
Target Audience
This project is particularly suitable for master’s students in physics, chemistry, or related fields. We are looking for highly motivated candidates with laboratory experience who enjoy working independently on experimental tasks. A strong interest in renewable energy and hands-on device fabrication is essential, while experience with vacuum systems or thin-film deposition techniques (such as spin coating, sputtering, or evaporation) is a plus.
Contact person: Ali Reza Nazari Pour (English-speaking)Optical Characterization and Simulation of Layers in Perovskite Solar Cells (Bachelor's or Master's Thesis)
Project Description
The aim of this work is to fully characterize the optical properties of the individual layers in perovskite solar cells. To this end, spectroscopic ellipsometry, UV-VIS spectroscopy, and scanning electron microscopy are used to determine key parameters such as layer thickness, the refractive index of the layers, and the absorption properties (extinction coefficient). Optical models for describing the complex refractive index are then fitted to the experimental data.
This is followed by a simulation of the entire solar cell. Here, the transfer matrix method is used to model absorption, reflection, and transmission within the solar cell stack. Additional simulation methods could be employed to investigate other optical effects in greater detail. Finally, the simulation results are compared with experimental data to verify agreement and, if necessary, identify opportunities for improvement in the simulation model.Objective and Skills to Be Acquired
The objective of the project is to gain a deeper understanding of the optical processes in perovskite solar cells by combining experimental and simulated data, and to be able to predict optical improvements through simulations, thereby contributing to the improvement of the efficiency of perovskite solar cells.
Contact Person: Aaron Schüller-RuhlFormation Mechanism of Low-Dimensional Perovskite Structures on 3D Perovskite Films (Bachelor's Thesis or Advanced Internship in Physics/Chemistry)
Project Description
Over the course of a 6- to 10-week work phase, the formation mechanism of low-dimensional perovskite structures (LDPs) that form on three-dimensional (3D) perovskite films will be investigated. The goal is to gain a better understanding of the formation, structure, and properties of LDPs, which are of great importance for the passivation of surfaces in perovskite solar cells.
The work involves the fabrication of thin perovskite films using established wet-chemical methods in glove boxes. The samples will then be characterized using various spectroscopic and microscopic methods. The focus is on spectroscopic and spatially resolved photoluminescence, supplemented by other analytical techniques such as UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Depending on the project’s progress, there is also the opportunity to fabricate complete perovskite solar cells and investigate the effect of LDPs in solar cells through current-voltage measurements.Requirements
We are looking for a dedicated student with an interest in experimental laboratory work and physicochemical problems. Candidates should enjoy hands-on work, have an interest in chemical processes, and be able to handle frustration well.
Contact: Malwine LühderElectro-Optical Simulation of Perovskite Solar Cells (SETFOS) (Master's Thesis)
Project Description
This project focuses on modeling single-junction and monolithic tandem perovskite solar cells using SETFOS. The work involves simulating light absorption, emission, scattering, and optical losses, taking into account roughness, crystallinity, and parasitic absorption in the various layers. On the electrical side, you will model electron, hole, and ion transport to reproduce JV curves, EQE, recombination pathways, ion migration, and hysteresis. Targeted characterization experiments, such as thickness variations and interlayer engineering, will be conducted to validate and refine the developed models.
Main Responsibilities
You will develop and test optoelectronic models in SETFOS, implement and optimize material parameters, simulate complete device stacks, and compare the simulation results with experimental data to improve the physical accuracy of the models.
Learning Outcomes
By completing this thesis, you will gain a solid understanding of the optical and electrical processes that govern perovskite solar cells, practical experience with drift-diffusion and transfer-matrix simulations, and the ability to link modeling with experimental observations for device optimization. Through regular discussions and presentations of your results within the team, you will also strengthen your scientific communication skills.Target Audience / Requirements
This project is intended for master’s students in physics who have prior knowledge of the physics of semiconductor and perovskite solar cells, basic programming and computational skills, and an interest in combining theoretical modeling with experiments. The ability to work independently and reliably is expected.
Contact Person: Christopher JanasSustainable Solar Cells (Bachelor's or Master's Thesis)
Project Description
In light of the global climate crisis and the fact that we are exceeding planetary boundaries, the expansion of renewable energy—particularly solar energy—is essential. Perovskite tandem solar cells promise significantly higher efficiencies than the currently dominant silicon technology. Given the need to install 2–5 TWp per year and the correspondingly high consumption of resources, sustainability requirements arise that must be taken into account in the energy transition. The current research landscape for perovskite solar cells appears to give little consideration to sustainability aspects in terms of guiding action and design. Instead, high-efficiency solar cells are usually assessed for sustainability in life-cycle analyses only after their design has been finalized. Certain aspects are considered only very sporadically, particularly those related to social sustainability. To be considered sustainable, however, a technology must meet the needs of the present generation without compromising the ability of future generations to meet their own needs. The goal of this project is to integrate technical development and sustainability and put this integration into practice.
Possible Areas of Focus
· Holistic sustainability assessments across the four life cycle phases of a perovskite solar cell: raw material extraction, manufacturing processes, operational phase, and end-of-life/recycling
· Identification and selection of more sustainable materials for the individual layers of perovskite solar cells
· Experimental fabrication of perovskite solar cells, including thin-film deposition and process optimizationSkills to Be Acquired
As part of this project, participants will develop:
· a comprehensive understanding of the interrelationships between technology development and sustainability,
· knowledge of various sustainability assessment methods (e.g., LCA, material criticality analyses, social sustainability indicators),
· expertise in the selection and evaluation of materials for sustainable photovoltaics,
· practical laboratory experience with fabrication and characterization methodsTarget Audience
The project is aimed at undergraduate and graduate students in physics who are interested in sustainable technology development, materials science, and experimental laboratory work.
Contact: Lea ObermüllerOptimization of the Automated Deposition and Crystallization of Perovskite Thin Films Using a Spin-Coating Robot (Bachelor's Thesis)
Project Description
Solar cells based on metal halide perovskites are a current area of research. In most laboratories, these solar cells are fabricated manually using thin-film deposition techniques such as spin coating. However, the optoelectronic quality of perovskite thin films—quantified by the photoluminescence quantum yield (PLQY)—is highly sensitive to the processing conditions during film deposition and to minor deviations in manual deposition techniques: Small variations in timing, acceleration, and solution dosage can significantly alter the defect density and the properties of charge carrier recombination.
In this project, a commercially available spin-coating robot designed for laboratory use is employed. This robot can automatically place the samples on the spin coater, apply the precursor solution, spin-coat them, and then place the sample on a hot plate for annealing. This approach allows you to systematically vary the deposition parameters and quantify their influence on the PLQY and the spatial homogeneity of the optoelectronic properties of perovskite thin films.Objective
• Programming the robot-assisted spin-coating system to perform controlled variations of the deposition parameters.
• Designing experimental campaigns and carrying out the automated fabrication of perovskite monolayers and multilayer stacks.
• Characterizing optoelectronic quality using photoluminescence (PL) imaging and UV-Vis spectroscopy.
• Correlating robot-assisted deposition parameters with PLQY, defect density, and film homogeneity.Skills to be acquired
• Chemical preparation of precursor solutions: Weighing, dissolving, and handling perovskite precursor materials.
• Robotics and automation: Programming and optimizing spin-coating robots for laboratory use.
• Thin-film processing: Spin coating, antisolvent techniques, and perovskite fabrication.
• Optoelectronic characterization: PL imaging, UV-Vis spectroscopy
• Semiconductor physics: PLQY, defect recombination, and interfacial charge extraction.
• Data analysis: Correlation of process parameters with optoelectronic quality.
• Scientific methodology: Experimental design and systematic parameter variation.Further Reading
· “Optimizing Perovskite Thin-Film Parameter Spaces with a Machine Learning-Guided Robotic Platform for High-Performance Perovskite Solar Cells,” Zhang et al. Adv. En. Mat. (2023). DOI: 10.1002/aenm.202370193
· “Repeatable Perovskite Solar Cells through Fully Automated Spin-Coating and Quenching.” Baumann et al., ACS Appl. Inter. (2024). DOI: 10.1021/acsami.4c13024
· www.sciprios.de
Contact: Dr. Lukas Wagner