AK Labs for Intelligence in Photonics

Activities in Research and Technology Transfer

For a full list of publications, please turn to http://scholar.google.de/citations?user=pkJOnicAAAAJ

Luminescence imaging - looking into the chemistry and physics of materials

Luminescence imaging is a powerful tool for the characterization and inspection of materials and devices. The current research focusses on the application in the production control and optimization for silicon solar cell and module manufacturing. Selected publications in this field are:

• M. Padilla, B. Michl, N. Hagedorn, C. Reichel, S. Kluska, A. Fell, M. Kasemann, Wilhelm Warta, M.C. Schubert. “Local Series Resistance Imaging of Silicon Solar Cells With Complex Current Paths.” IEEE Journal of Photovoltaics 5, no. 3 (May 2015): 752–58.
• Y. Augarten, T. Trupke, M. Lenio, J. Bauer, J.W. Weber, M.K. Juhl, M. Kasemann, O. Breitenstein. “Calculation of Quantitative Shunt Values Using Photoluminescence Imaging: Calculation of Quantitative Shunt Values Using PL Imaging.” Progress in Photovoltaics: Research and Applications 21 (2013): 933–41.
• M. Kasemann, L. M. Reindl, B. Michl, W. Warta, A. Schütt, J. Carstensen, “Contactless Qualitative Series Resistance Imaging on Solar Cells”, IEEE Journal of Photovoltaics, 2 (2), 181–183 (2012)
• M. Kasemann, D. Grote, B. Walter, W. Kwapil, T. Trupke, Y. Augarten, R. A. Bardos, E. Pink, M. D. Abbott, W. Warta, “Luminescence imaging for the detection of shunts on silicon solar cells”, Progress in Photovoltaics: Research and Applications, 16 (4), 297–305 (2008)
• M. Kasemann, M. C. Schubert, M. The, M. Köber, M. Hermle, W. Warta, “Comparison of luminescence imaging and illuminated lock-in thermography on silicon solar cells”, Applied Physics Letters, 89 (22), 224102 (2006)

Photovoltaic energy harvesting - ambient power for electronic systems

Commercial photovoltaic cells used in energy harvesting applications suffer from low power conversion efficiencies at low light intensities. Typical efficiencies of of cells available on the market are in the range of 2 to 5% at intensities of 100 Lux. This hold for cells made from amorphous silicon as well as for current crystalline silicon cells. Selected publications in this field are:

• K. Rühle, M.K. Juhl, M. D. Abbott, and Martin Kasemann. “Evaluating Crystalline Silicon Solar Cells at Low Light Intensities Using Intensity-Dependent Analysis of I-V-Parameters.” IEEE Journal of Photovoltaics 5, no. 3 (May 2015): 926–31.
• K. Rühle, M. Kasemann. “Selection and Dimensioning of Photovoltaic Harvester for Wireless Sensor Systems.” In Proceedings of Sensors and Measuring Systems 2014; 17. ITG/GMA Symposium, Nürnberg, 2014.
• M. Kasemann, J. Kokert, S.M. Torres, K. Ruhle, L.M. Reindl. “Monitoring of Indoor Light Conditions for Photovoltaic Energy Harvesting.” In Proceedings of the 11th IEEE International Multi-Conference on Systems, Signals Devices (SSD), 2014, 1–5, 2014.
• K. Rühle, S.W. Glunz, and M. Kasemann, “Towards New Design Rules for Indoor Photovoltaic Cells”, Proceedings of the 38th IEEE Photovoltaic Specialists Conference, 2588–2591 (2012)

Nanolayers on Silicon - enabling passivated contacts and novel devices

In this are we focus on the deposition and characterization of passivated oxide layers. Applications are passivated contacts and carrier selective barriers in conjunction with thin metal films on silicon. Selected publication are under way:

• K.M. Gad, D. Vössing, P. Balamou, D. Hiller, B. Stegemann, H. Angermann, M. Kasemann, "High quality tunneling oxides for passivated contacts and heterojunctions for high efficiency silicon solar cells", Proceedings of the 42nd IEEE Photovoltaic Specialists Conference, New Orleans, 2015 
• K. Rühle, M. Rauer, M. Rüdiger, J. Giesecke, T. Niewelt, C. Schmiga, S. W. Glunz, and M. Kasemann, “Passivation Layers for Indoor Solar Cells at Low Irradiation Intensities”, Energy Procedia, 27, 406–411 (2012)