Metrology and Simulation

Our work in the research topic "Metrology and Simulation" is characterized by our expertise in the analysis of solar cells and modules, based on our many years of experience in the fields of technology and metrology and physics. We have detailed knowledge of solar cell structures and physics, metrological concepts and simulation methods, as well as extensive data collections on solar cell parameters. In addition, we use powerful machine learning and artificial intelligence approaches for data analysis.  

Our work focuses on the development of measuring devices and analysis methods to improve materials, solar cells and modules and to optimize inspection and quality assurance in production. We develop solutions together with and for measurement technology and sensor manufacturers, material, cell and module manufacturers, providers of data analysis systems and research institutes.  

We offer solutions in the areas of quality assurance, automated process and production control, measurement method and measurement system development, material and cell analysis, simulation and modeling, as well as automated data analysis and image processing/artificial intelligence. We offer certified solar cell measurements in our independent and accredited calibration laboratory CalLab PV Cells.

• Measurement Techniques for Process and Material Analysis
• Measurement Method for Cell Analysis
• Measurement Method for Module Analysis
• Process Simulation
• Simulation and Modeling of Cells and Modules

In order to obtain detailed information for the evaluation of materials for solar cells, we develop new measurement approaches and optimize existing methods. In addition to the precise analysis of silicon materials for solar cells, our analyses also focus on perovskite absorbers and various functional layers, for example.

Our R&D Services Include:

• Determining the concentration of impurity atoms in silicon (e.g. hydrogen, iron)
• Determining the charge carrier lifetime and internal voltage (iVoc) in silicon or perovskites as materials in single or multiple solar cells
• Detailed analyses using photoluminescence and Raman spectroscopy, scanning electron microscopy and other methods
• Inline analysis for silicon wafers and functional layers

We conduct comprehensive solar cell testing to thoroughly evaluate solar cell quality and performance. We offer global cell analysis in the laboratory under offline conditions, as well as in-line under industry-compatible conditions, including calibrated measurements for single and multiple solar cells. Spatially resolved, camera-based measurement methods using photoluminescence or thermography enable the evaluation of cell homogeneity and local defects that can reduce global cell performance. We investigate single and multiple solar cells. In addition to silicon solar cells, we are particularly working on perovskite-silicon tandem solar cells and multiple solar cells based on III-V materials.

Our R&D Services Include:

• Optical-electrical analysis of solar cells
• Identification of loss channels and efficiency limitations
• Development of new measurement methods

We investigate solar cells encapsulated in modules – from small laboratory laminates to large-format PV modules – using a variety of measurement methods. In the Testlab PV Modules, we carry out the tests listed in the IEC and European standards for type approvals. In the CalLab PV Modules, we determine I-V characteristics under STC or NOCT conditions (standard testing conditions, nominal operating cell temperature) as well as temperature and irradiation dependencies.

We develop new measurement methods, for example for perovskite-silicon tandem modules, using LED-based current-voltage analysis.

Our R&D Services Include:

• Calibration of photovoltaic modules
• Quality and reliability testing for modules
• Development of new measurement methods

With the help of process simulations, wet-chemical processes, for example, can be investigated. Processes such as surface reactions, which depend on the flow conditions in the immediate vicinity, are very difficult to access experimentally. Questions such as process homogeneity can be clarified experimentally in extensive experimental designs, but this is both time-consuming and resource-intensive. Simulations in which flows and reactions are combined to investigate the processes at the surface with spatial resolution can help here.

We have detailed approaches for opto-electrical modeling of solar cell structures on silicon, perovskite and III-V basis by means of drift-diffusion modeling and the simulation of entire solar cells.

These opto-electrical simulations take into account the phenomena of optical interference, generation and recombination of charge carriers, charge carrier transport at heterojunctions, tunneling processes, photon recycling and ion migration.

Numerical simulations can significantly accelerate the development process of complex solar cell structures in particular.