Science and Research
Meet Suniva's Scientists
Ajeet Rohatgi, Ph.D.
Founder, CTO
Dr. Ajeet Rohatgi is a Regents' Professor and a Georgia Power Distinguished Professor in the School of Electrical Engineering at the Georgia Institute of Technology (Georgia Tech), where he joined the ECE faculty in 1985. He is highly regarded as one of the world's leading research scientists in photovoltaic (PV) technology, and is the founding director of the University Center of Excellence for Photovoltaic Research and Education (UCEP) at Georgia Tech. Dr. Rohatgi is also the Founder and CTO of Suniva®, Inc. and has positioned the company as a U.S. leader in the research, development and manufacturing of high-efficiency, low-cost monocrystalline PV cells, using unique processes and techniques that evolved from his work at UCEP. Dr. Rohatgi continues his research interests in the development of cost and efficiency roadmaps for attaining grid parity with silicon PV, and innovations in cell design and technology.
Under Dr. Rohatgi's leadership, Suniva has accomplished several industry firsts and achievements in manufacturing, technology, research, and development, including the fastest ramp-up to 100MW production in the industry; the raising of $130 million in capital following the formation of Suniva in 2007; the successful production of cell efficiencies exceeding 19% and R&D cell efficiencies exceeding 20%. Today, Suniva is the highest cell efficiency producer in the U.S.
Dr. Rohatgi is an IEEE Fellow. He has published more than 370 technical papers in the PV field and has been awarded 11 patents. Dr. Rohatgi has been widely recognized for his research and development contributions:
- Recipient of the 2010 Outstanding Achievement in Research Innovation Award, nominated on behalf of the faculty of the School of Electrical and Computer Engineering
- Leadership in Technology award by Renewable Energy World for his achievements in advancing the market for renewable energy in North America, 2010
- Envention Award by Atlanta Business Chronicle for conservation and pollution-curbing efforts, 2009
- Hoyt Clarke Hottel Award by the American Solar Energy Society (ASES) award committee for outstanding educator and innovator in the field of photovoltaics , 2009
- Thought Leadership Award finalist by the Aspen Institute's 2009 Energy & Environment Awards, 2009
- Climate Protection Award by 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 by Power Finance & Risk Magazine, 2008
- Georgia Institute of Technology Outstanding Research Program Development Award, 2007
- William Cherry Award by the IEEE Photovoltaic Specialists Conference, 2003
- Rappaport Award by the U.S. Department of Energy/NREL, 2003
- Georgia Tech Distinguished Professor Award, 1996
- As part of the 1996 Olympic Games in Atlanta, Dr. Rohatgi and his team designed and installed the world's largest grid-connected, roof-top PV system on the Georgia Tech Aquatic Center
- Westinghouse Engineering Achievement Award, 1984
Dr. Rohatgi received a B.S. degree in Electrical Engineering from the Indian Institute of Technology, Kanpur, in 1971, and a M.S. degree in Materials Engineering from the Virginia Polytechnic Institute and State University, Blacksburg, VA, in 1973. He received a Ph.D. in Metallurgy and Material Science from Lehigh University, Bethlehem, PA, in 1977. Prior to joining the Electrical Engineering faculty at the Georgia Institute of Technology, Dr. Rohatgi was at the Westinghouse Research and Development Center in Pittsburgh, PA in 1977 and became a Westinghouse Fellow while working on the science and technology of photovoltaic and microelectronic devices.
Selected Papers:
DEVELOPING NOVEL LOW-COST, HIGH-THROUGHPUT PROCESSING TECHNIQUES FOR 20% EFFICIENT MONOCRYSTALLINE SILICON SOLAR CELLS
HIGH-EFFICIENCY (19%) SCREEN-PRINTED TEXTURED CELLS ON LOW-RESISTIVITY FLOAT-ZONE SILICON WITH HIGH SHEET-RESISTANCE EMITTERS
Daniel L. Meier, Ph.D.
Chief Scientist
As Chief Scientist, Dan leads the development of new technology at Suniva and advises on a variety of technical areas. He works closely with Suniva founder and CTO, Dr. Ajeet Rohatgi, and the R&D team on new device architectures and processes designed to continually improve Suniva's high cell efficiencies while maintaining low costs. Dan also supports the module side of Suniva's business, providing both technical and application direction. He joined Suniva as one of its first employees in 2007.
Dan joined Suniva from the technical staff of the National Renewable Energy Laboratory (NREL) where he worked from 2006 to 2007on advanced cell designs involving amorphous silicon/crystalline silicon heterojunctions, as well as issues related to the production of silicon feedstock by novel processes.
Prior to NREL, Dan served as Vice President of Engineering from 2003 to 2006 at 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. From 1994 until 2003, Dan was Chief Scientist for the start-up company EBARA Solar, 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.
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 more than 75 technical papers in conference proceedings and archival journals, and holds 11 US patents. Dan has been honored with three Westinghouse Signature Awards for excellence in engineering.
Selected Papers:
DEVELOPING LOW-COST, HIGH THROUGHPUT PROCESSING TECHNIQUES FOR 20% EFFICIENT MONOCRYSTALLINE CELLS
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
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.
Senior Engineer
As a senior 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
