MSE Colloquium: Sylvain Marsillac, Grain and Grain Boundary Engineering for High Efficiency Cu(In,Ga)Se2 Solar Cells

Dept of Electrical and Computer Engineering, Old Dominion Univ.

All dates for this event occur in the past.

264 MacQuigg Labs
105 W. Woodruff Ave.
Columbus, OH 43210
United States

Abstract

As world energy demands continue to increase, the need to generate electricity from a broader variety of sources, including renewables, is more important than ever. With costs still 30% higher than those of natural gas, solar energy is a viable contender but more progress is needed to level the playing field with other forms of energy generation. Among the cost drivers that could allow for manufacturing price reductions, high efficiency is critical. In the case of Cu(In,Ga)Se2 solar cells, one of the most prominent polycrystalline thin film solar cells on the market, generating high efficiencies involves engineering both the grains and the grain boundaries, and therefore produces specific requirements. Among those are managing (i) the composition of all elements in the quaternary alloy and the phases in presence, (ii) the deposition process to allow for maximum grain growth and band gap engineering, and (iii) the diffusion of specific impurities for passivation of the grain boundaries. Solutions to these problems, involving synergistic fabrication, characterization and modeling, will be presented and include a multi-step deposition process, controlled gallium content grading for the absorber layer, enhanced in-situ monitoring (by real time spectroscopic ellipsometry), and newly developed alkaline post-deposition treatments. By modifying the deposition process, and engineering both the grain and grain boundary, we will show how the fine-tuning of the Cu(In,Ga)Se2 material properties can lead to enhance solar cell efficiency.  

Bio

 

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Dr. Sylvain Marsillac

Dr. Sylvain Marsillac has devoted his career to the engineering and materials science of inorganic thin films (both materials and devices), and their fabrication and characterization, specifically for photovoltaic applications. His research includes the successful application of many semiconductors to the field of thin film solar cells (e.g. Cu(In,Ga)Se2, CdTe and a-Si). He has also developed unique skills and knowledge in real time spectroscopic ellipsometry (RTSE), and has applied it to guide the fabrication of many semiconductors, metals and ceramics. In parallel, he has also developed excellent connections with industry and contributes to the enhancement and understanding of PV systems, through interdisciplinary and collaborative work. With more than 160 papers in peer-reviewed journals and conference proceedings, and participation in 30+ proposals totaling over $40M (with a personal share of more than $9M), he has been able to successfully develop and advance applied science and transfer those results into product applications.

Since 2011, he has been the Faculty Director of the Virginia Institute of Photovoltaics (VIPV) at Old Dominion University, Norfolk, VA. This is an interdsicplinary center that focuses on materials and devices, spanning work in the field of PV from the nano-scale to the giga-scale. He is also the lead of ODU’s new pedagogic effort to develop an undergraduate and a graduate program for PV engineering education. Prior to joining ODU, where he is also a Professor of Electrical Engineering, Dr. Marsillac was on the faculty at the University of Toledo, where he distinguished himself by co-directing the Ohio Wright Center for Photovoltaics.

Dr. Marsillac contributes to the profession as an Associate Editor of the IEEE Journal of Photovoltaics. He has also been the Chair of Area 2 “Chalcogenide Thin Film Solar Cells and Related Materials” at four IEEE Photovoltaic Specialist Conferences (PVSC), and an Organizing Committee member of PVSC for the last seven years. In 2015, he received the IEEE PVSC Napkin award in recognition of his dedication to enhancing the quality of the conference technical program. At ODU, Dr. Marsillac has received six different awards for his excellence in research, teaching and service and was nominated three times for the State Council of Higher Education for Virginia (SCHEV) Outstanding Faculty Award. He was also recently selected by the Governor of Virginia as a member of the inaugeral Virginia Solar Energy Development Authority where he helps direct PV efforts in the Virginia Commonwealth.

Dr. Marsillac received his Ph.D. (1996) and M.S. (1993) in Materials Science and Engineering from the University of Nantes (France).