Science and Research
Meet Suniva's Scientists
Ajeet Rohatgi, Ph.D.
Founder, CTO
Dr. Rohatgi is the founder and CTO of Suniva, Inc., leading the development of cost and efficiency roadmaps for attaining grid parity with silicon PV cells. He received a B. S. degree in Electrical Engineering from the Indian Institute of Technology in 1971, an M.S. in Materials Engineering from Virginia Polytechnic Institute and State University in 1973, and a Ph.D. in Metallurgy and Materials Science from Lehigh University in 1977.
Dr. Rohatgi joined the Westinghouse Research and Development Center in Pittsburgh, Pennsylvania in 1977 and became a Westinghouse Fellow while working on the science and technology of photovoltaic and microelectronic devices.
Dr. Rohatgi is a Regents' Professor and a Georgia Power Distinguished Professor in the School of Electrical Engineering at Georgia Tech. He joined the faculty in 1985 and started a photovoltaics program that has become one of the best in the country. An internationally recognized leader in photovoltaics, Dr. Rohatgi is also the founding director of the first university-based DOE Center of Excellence in Photovoltaic Research and Education (UCEP). He has authored more than 370 publications and holds 11 U.S. patents.
Dr. Rohatgi's research interests include:
- Development of cost and efficiency roadmaps for attaining grid parity with silicon PV cells
- Growth and characterization of low-temperature and high-performance dielectrics
- Understanding impurity effects in silicon solar cells
- Gettering and passivation of defects in solar grade silicon
- Defects and carrier lifetime in semiconductors
- Rapid thermal processing of silicon devices
- Growth and optoelectronic properties of compound semiconductors
- Performance and economics of photovoltaic systems
Dr. Rohatgi has been widely recognized for his research and development contributions:
- Westinghouse Fellow
- Fellow of the Institute of Electrical and Electronics Engineers
- Georgia Tech Distinguished Professor Award
- William Cherry Award from the IEEE Photovoltaic Specialists Conference
- Thomas D. Callinan Award from the Electrochemical Society
- Rappaport Award from the U.S. Department of Energy/NREL
- Founding Director, University Center of Excellence in Photovoltaics Research and Education (UCEP), a U.S. DOE-funded center)
- Envention Award from the Atlanta Business Chronicle for conservation and pollution-curbing efforts, 2009
- Hoyt Clarke Hottel Award from the American Solar Energy Society (ASES) as outstanding educator and innovator in the field of photovoltaics, 2009
- Thought Leadership Award from the Aspen Institute's 2009 Energy & Environment Awards
- Climate Protection Award from the U.S. Environmental Protection Agency (EPA) for dedication and technical innovation in PV, 2009
- One of The Five Most Influential People in Renewable Energy from Power Finance & Risk Magazine, 2008
- Georgia Institute of Technology Outstanding Research Program Development Award, 2007
Please click for Dr. Rohatgi's complete CV.
Selected Papers:
HIGH-EFFICIENCY (19%) SCREEN-PRINTED TEXTURED CELLS ON LOW-RESISTIVITY FLOAT-ZONE SILICON WITH HIGH SHEET-RESISTANCE EMITTERS
Daniel L. Meier, Ph.D.
Vice President of Research and Development
Dan joins Suniva from the technical staff of the National Renewable Energy Laboratory (NREL), where he worked on advanced cell designs involving amorphous silicon/crystalline silicon heterojunctions and on issues related to the production of silicon feedstock by novel processes.
Prior to NREL, Dan served as V.P. of Engineering from 2003 to 2006 with Solar Power Industries. His staff produced 265 kg multicrystalline ingots by the directional solidification technique, 156 mm square wafers from the ingots, and developed processes for fabricating multicrystalline cells from these wafers. Cell production was 3.5 MW in 2005. Before SPI, Dan became Chief Scientist for EBARA Solar, a start-up company in 1994. There he was responsible for the development of dendritic web silicon ribbon crystal growth and cell fabrication in a pilot-scale facility. His team stabilized the growth of dendritic web crystals by introducing a magnetic field to allow the production of long crystals (typically 10 m) and developed a unique cell structure based on an aluminum alloy back p-n junction. Modules were made for successful demonstration projects up to 19 kW in size.
Dan began his career in photovoltaics at the Westinghouse R&D Center in 1980 where he worked on the design, fabrication, and characterization of silicon solar cells from thin (100 micron) dendritic web ribbon crystals. He also participated in the fabrication and testing of superconductive components for low-loss microwave applications and superconductive digital integrated circuits. He left Westinghouse in 1994 with the ranking of Fellow Scientist.
Dan holds a B.S. from St. Vincent College and an M.S. and Ph.D. from Carnegie-Mellon University, all in physics. He has published over 75 technical papers in conference proceedings and archival journals and holds 11 US patents. He was the recipient of three Westinghouse Signature Awards for excellence in engineering.
Selected Papers:
DETERMINATION OF SURFACE RECOMBINATION VELOCITIES FOR THERMAL OXIDE AND AMORPHOUS SILICON ON FLOAT ZONE SILICON
THE EFFECT OF DOPING DENSITY AND INJECTION LEVEL ON MINORITY -CARRIER LIFETIME AS APPLIED TO BIFACIAL DENDRITIC WEB SILICON SOLAR CELLS
SELF-DOPING CONTACTS TO SILICON USING SILVER COATED WITH A DOPANT SOURCE
ALUMINUM ALLOY BACK P-N JUNCTION DENDRITIC WEB SILICON SOLAR CELL
BACK SURFACE FIELD EFFECTS IN THE 17.3% EFFICIENT N-TYPE DENDRITIC WEB SILICON SOLAR CELLS
Ben M. Damiani, Ph.D.
Senior Engineer
As Senior Engineer in Research and Development at Suniva, Ben is responsible for increasing cell efficiency and streamlining the fabrication process using next generation technologies. He has been instrumental in developing Suniva's next generation cell technology platform.
Prior to joining Suniva, Ben worked in the LTD organization at Intel Corporation during 2004-2007, developing next-generation IC's. His group was responsible for the successful development and ramp-up of the 65nm and 45nm node. Along with next generation chip development, Ben was responsible for advanced process control methods for high-volume manufacturing (HVM). Ben also has years of experience in the photovoltaics industry, working in areas from seed crystal to completed modules, with a focus on process characterization and optimization. He is the author of 14 papers on photovoltaics.
Ben received his BSEE, MSEE, and Ph.D. in Electrical Engineering from the Georgia Institute of Technology, with a focus on photovoltaics. During graduate school, Ben concentrated his studies on Light Induced Degradation and developing rapid low-cost manufacturable solar cell processes. Ben also spent six months as a Guest Scientist at the Fraunhofer ISE group in Freiburg, Germany in 1998.
Selected papers:
LIGHT INDUCED DEGRADATION IN PROMISING MULTI-CRYSTALLINE
SILICON MATERIALS FOR SOLAR CELL FABRICATION
Vijay Yelundur, Ph.D.
Senior Engineer
Dr. Vijay Yelundur is a Senior Engineer in Suniva's Research and Development. His current area of research is the design, fabrication and characterization of high-efficiency solar cells on Czochralski silicon wafers. Vijay is further instrumental in the development of 20%-efficiency cells as part of Suniva's technology roadmap.
Vijay comes to Suniva from the Georgia Institute of Technology, where he received his B.S. and Ph.D. in Materials Science and Engineering. Vijay also worked with Suniva Founder and CTO, Dr. Ajeet Rohatgi, at Georgia Tech's University Center of Excellence for Photovoltaic Research and Education (UCEP). At UCEP, Vijay was a Senior Research Engineer, working on the optimization of silicon solar cell performance via rapid thermal processing, among other research projects. He is the author of more than 30 papers in crystalline silicon photovoltaics.
Selected Papers:
IMPROVED STRING RIBBON SILICON SOLAR CELL PERFORMANCE BY RAPID THERMAL FIRING OF SCREEN-PRINTED CONTACTS
AL-ENHANCED PECVD SiNx INDUCED HYDROGEN PASSIVATION IN STRING RIBBON SILICON
Adam M. Payne, Ph.D
Senior Scientist
As a Senior Scientist at Suniva, Adam is responsible for the development of n-type solar cells. Since joining Suniva in 2008, Adam has been instrumental in overseeing the construction and implementation of the Development Laboratory and has served as liaison for joint research projects with Georgia Tech's University Center of Excellence for Photovoltaic Research and Education (UCEP). He also works closely with Suniva's manufacturing team on optimizing the refractive index of the anti-reflection coating of Suniva's solar cells.
Prior to his role at Suniva, Adam was a research scientist at Georgia Tech from 2003 until 2005 where he worked on GaN-based light emitting diodes and the use of InGaN as a photovoltaic material. During 1999 - 2002, Adam worked at Aegis Semiconductor, a start-up company which produces tunable thin film filters for the optical communications market. He has published 10 papers on photovoltaics and holds four U.S. patents.
Adam received his B.S. from Yale University in applied physics. He spent an additional year at the University of Cambridge, where he read for an M.Phil in microelectronic engineering and semiconductor physics. Adam received his Ph.D. from Princeton University in electrical engineering. His doctoral thesis researched amorphous silicon-germanium alloys for solar cells, as well as using dicholorosilane as an alternative source gas for a-Si:H. While affiliated with the Princeton Environmental Institute (1997-2002), Adam worked on estimating the long-term costs of solar cells as well as analyzing the impact of net metering on the geographic distribution of photovoltaics in the U.S. After receiving his Ph.D., Adam was an STA International Research Fellow at the Electrotechnical Laboratory in Tsukuba, Japan, where he worked on plasma-enhanced CVD of a-Si:H.
InGaN- A NEW SOLAR CELL MATERIAL
THE EFFECT OF CHLORINE ON DOPANT ACTIVATION IN HYDROGENATED AMORPHOUS SILICON
ACCELERATING RESIDENTIAL PV EXPANSION: DEMAND ANALYSIS
FOR COMPETITIVE ELECTRICITY MARKETS
Vinodh Chandrasekaran, M.S.
Engineer
As an engineer in Research and Development at Suniva, Vinodh is primarily responsible for development of contacts to advanced cell structures. He also focuses on improved surface passivation and development of high-efficiency n-type cells. Vinodh has been instrumental in the development and transfer of technology from the lab, achieving the fastest ramp-up in solar manufacturing with cell efficiency levels of more than 18% in production and 20% in the development lab.
Prior to joining Suniva, Vinodh was with Solar Power Industries (SPI), where he worked on the development and manufacturing of multicrystalline silicon solar cells. His main focus was on process development and optimization, along with diagnosis and characterization. Before his work as a cell processing engineer, Vinodh was responsible for bringing the wire saw process into the production of wafers from ingots cast in-house at SPI. He was also involved in the production of multicrystalline ingot growth.
Vinodh received his MSEE from the University of South Florida, specializing in thin film photovoltaics. His thesis focus was on improving performance and development of manufacture-friendly processes for thin film CIGS solar cells. Vinodh received his B.E. in Electronics and Communication Engineering from the University of Madras, India.
Selected Papers:
DETERMINING COMPONENTS OF SERIES RESISTANCE FROM MEASUREMENTS ON A FINISHED CELL
