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Photo file: 
Full name: 
Ajeet Rohatgi
Job title: 
Regents Professor
; John H. Weitnauer, Jr. Chair in the College of Engineering; Georgia Research Alliance Eminent Scholar
Technical Interest Groups: Electrical Energy, Nanotechnology, Optics and Photonics
Email address: 
email
Work phone: 
404/894-7692
Fax: 
404.894.5934
Office: 
VL W121

Dr. Rohatgi received the B.S. (E.E.) degree from Indian Institute of Technology in 1971, the M.S. (Materials Engineering) from Virginia Polytechnic Institute and State University in 1973, and the Ph.D. in Metallurgy and Materials Science from Lehigh University in 1977.

He 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 joined the ECE faculty at Georgia Tech in 1985 and started a program on photovoltaics, which has become one of the best in the country. He has become an internationally recognized leader in photovoltaics. He is the founding director of the first university-based DOE Center of Excellence in Photovoltaic Research and Education. He is the author of more than 300 publications and holds 10 U.S. patents. Dr. Rohatgi has received numerous awards and distinctions from professional societies and Georgia Tech. He is the founder and CTO for Suniva.

Research interests: 
  • Modeling and fabrication of low-cost high-efficiency silicon solar cells
  • Growth and characterization of low-temperature and high-performance dielectrics
  • Defects and carrier lifetime in semiconductors
  • Rapid thermal processing of silicon devices
  • Growth and optoelectronic properties of compound semiconductors
Distinctions: 
  • 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 (a U.S. DoE-funded center)

A. Rohatgi, S. Narasimha, A. Ebong and P. Doshi, "Understanding and Implementation of Rapid Thermal Technologies for Low-Cost High-Efficiency Silicon Solar Cells," IEEE Transaction on Electron Devices vol. 46, no. 10, pp. 1970 - 1977, October, 1999.

T. Krygowski, Ajeet Rohatgi: "A Simultaneously Diffused Textured, In-situ Oxide AR-Coated Solar Cell Process for High Efficiency Silicon Solar Cells," IEEE Electron Devices Letters, vol. 45, no. 1, pp. 194-199, 1998.

J.I. Hanoka, S. Kamra, S. Narasimha, Ajeet Rohatgi, R.F. Wallace: "Thin Silicon Ribbon for High Efficiency Polycrystalline Solar Cells," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 99-102, 1997.

Ajeet Rohatgi: "Applied Research and Exploratory Development," invited presentation, National Center for PV Workshop on PV Program Strategic Directions, Lakewood, CO, 1997.

Ajeet Rohatgi: "A Simultaneously Diffused Textured, In-situ Oxide AR-coated Solar Cell Process for High Efficiency Silicon Solar Cells," invited presentation, 26th IEEE Photovoltaic Specialists Conference, Anaheim, CA, September/October 1997, 1997.

G. Crotty, T. Krygowski, D.L. Meier, S. Narasimha, Ajeet Rohatgi: "Back Surface Field and Emitter Passivation Effects in the Record High Efficiency N-Type Dendritic Web Silicon Solar Cell," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 235-238, 1997.

Ajeet Rohatgi: "The Effects of Rapid Pre-getter Anneal Treatments on the Performance of Cast mc-Si Solar Cells," invited presentation, Seventh Workshop on the Role of Impurities and Defects in Silicon, Vail, CO, 1997.

P. Doshi, G.E. Jellison, Ajeet Rohatgi: "Characterization and Optimization of Absorbing PECVD Antireflection Coatings for Silicon Photovoltaics," Journal of Applied Optics, vol. 36, no. 30, pp. 7826-7837, 1997.

T. Krygowski, Ajeet Rohatgi: "Simultaneous P and B Diffsuion, In-situ Surface Passivation, Impurity Filtering, and Gettering for High-efficiency Silicon Solar Cells," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 19-24, 1997.

M. Begovic, R. Long, Ajeet Rohatgi, M. Ropp: "Design Consideration for Large Roof-integrated Photovoltaic Arrays," Progress in Photovoltaics, vol. 5, pp. 55-67, 1997.

Miroslav M. Begovic, A. Rohatgi, M. Ropp: "Design Considerations for Large Roof-mounted Photovoltaic Arrays," Progress in Photovoltaics Research and Applications, vol. 5, pp. 55-67, 1997.

G. Crotty, J.I. Hanoka, Ajeet Rohatgi, R.L. Wallace: "Thin Film String Ribbon," Solar Energy Materials and Solar Cells, vol. 48, pp. 179-186, 1997.

S. Narasimha, Ajeet Rohatgi: "Optimized Aluminum Back Surface Field Techniques for Silicon Solar Cells," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 62-66, 1997.

P. Doshi, J. Mejia, Ajeet Rohatgi, K. Tate: "Modeling and Characterization of High-efficiency Silicon Solar Cells Fabricated by Rapid Thermal Processing, Screen Printing, and Plasma Enhanced Chemical Vapor Deposition," IEEE Transactions on Electron Devices, vol. 44, no. 9, pp. 1417-1424, 1997.

Miroslav M. Begovic, A. Rohatgi, M. Ropp: "Determination of Curvature Derating Factor for the Georgia Tech Aquatic Center PV Array," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, Anaheim, CA, September/October 1997, 1997.

L. Cai, S. Narasimha, Ajeet Rohatgi: "Gettering and Passivation of High Efficiency Multicrystalline Silicon Solar Cells," American Institute of Physics Conference Proceedings, vol. 394, pp. 199-213, 1997.

P. Doshi, J. Jeong, J. Moschner, S. Narayanan, Ajeet Rohatgi, R. Singh: "Characterization and Application of Rapid Thermal Oxide Surface Passivation for the Highest Efficiency RTP Silicon Solar Cells," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 87-90, 1997.

T.F. Ciszek, W.A. Doolittle, Ajeet Rohatgi, T.H. Wang: "Minority-carrier Lifetime Degradation in Silicon Co-doped with Iron and Gallium," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 59-62, 1997.

P. Doshi, T. Krygowski, Ajeet Rohatgi: "Pushing the Frontiers of Silicon PV Technologies: Novel Approaches to High Efficiency, Manufacturable Silicon Cells," American Institute of Physics, vol. 404, pp. 109-116, 1997.

Ajeet Rohatgi: "Solar Power: Clean Electricity for the 21st Century," invited presentation, Georgia Tech Student Chapter of the IEEE/PES, 1997.

M. Begovic, Ajeet Rohatgi, M.E. Ropp: "Determination of the Curvature Mismatch Factor for the Georgia Tech Aquatic Center Photovoltaic Array," Proceedings of the 26th IEEE Photovoltaic Specialists Conference, pp. 1297-1300, 1997.

A. Rohatgi, S. Narasimha, S. Kamra, "Fabrication and Analysis of Record High 18.2% Efficient Solar Cells on Multicrystalline Silicon Material," IEEE Electron Device Letters, vol. 17, no. 8, pp. 401-403, August 1996.

R.K. Feeney, D. Hertling, Ajeet Rohatgi: "Electrical Conductivity Tester and Methods Thereof for Accurately Measuring Time-Varying and Steady State Conductivity Using Phase Shift Detection," U.S. Patent 5,508,610, 1996.

S. Kamra, C.P. Khattak, S. Narasimha, Ajeet Rohatgi: "The Optimization and Fabrication of High-Efficiency HEM Multicrystalline Silicon Solar Cells," Proceedings of the 25th IEEE Photo-voltaic Specialists Conference, 1996.

R.K. Feeney, D.R. Hertling, Ajeet Rohatgi: "Time Varying Electrical Conductivity Tester Using Frequency Discrimination and Power Detector and Methods," U.S. Patent no. 5,495,170, no. 5, 1996.

Miroslav M. Begovic, R. Long, A. Rohatgi: "Photovoltaics in Architecture: The Design, Construction, and Monitoring of a Photovoltaic Power System on the Georgia Tech Aquatic Center," 1996 Conference on Application of Photovoltaics in Architecture, Boston, MA, January, 1996.

P. Doshi, K. Emery, H. Field, S. Kamra, C.P. Khattak, S. Narasimha, Ajeet Rohatgi: "Record High 18.6% Efficient Solar Cell on HEM Multicrystalline Material," Proceedings of the 25th IEEE Photovoltaic Specialists Conference, 1996.

Z. Chen, P. Doshi, J. Mejia, Ajeet Rohatgi, K. Tate: "Processes for Producing Low Cost High Efficiency Silicon Solar Cells," U. S. Patent no. 5,520,271, no. 5, 1996.

R.K. Feeney, David R. Hertling, A. Rohatgi: "Electrical Conductivity Tester and Methods Thereof," patent #5,495,170, 1996.

A.X. Coles, R.A. Gebhardt, Ajeet Rohatgi: "Optimization of Porous Silicon Reflectance for Solar Cell Applications," Proceedings of the Materials Research Society, 1996.

P. Doshi, S. Kamra, J. Mejia, M. Narayanan, Ajeet Rohatgi, R. Singh, K. Tate: "High Efficiency Large and Small Area Si Solar Cells Using Low-Cost Rapid Thermal Processing, Screen-Printing, and Plasma-Enhanced Chemical Vapor Deposition," Proceedings of the 25th IEEE Photovoltaic Specialists Conference, 1996.

W. Doolittle, Ajeet Rohatgi: "Deep Level Transient Spectroscopy (DLTS) System and Method," U.S. Patent 5,521,839, 1996.

T. Krygowski, Ajeet Rohatgi, P. Sana: "A Novel Technology for the Simultaneous Diffusion of Boron and Phosphorus in Silicon," Proceedings of the 25th IEEE Photovoltaic Specialists Conference, 1996.

Miroslav M. Begovic, R. Long, A. Rohatgi: "The Design, Construction, and Monitoring of a Photovoltaic System on the Georgia Institute of Technology Aquatic Center," Proceedings of the 13th European Photovoltaic Solar Energy Conference and Exhibition, Nice, France, 1995.

L. Cai, A. Doolittle, P. Doshi, T. Krygowksi, Ajeet Rohatgi: "Application of PECVD for Bulk and Surface Passivation of High Efficiency Silicon Solar Cells," Fifth Workshop on the Role of Impurities and Defects in Silicon Device Processing Copper Mountain, CO, 1995.

B.N. Beckloff, W.J. Lackey, S. Narashima, Ajeet Rohatgi, A. Smith: "Low Cost, Thin Film Solar Cells Prepared by Chemical Vapor Deposition of Titanium Diboride and Silicon," disclosure award granted in 1995, 1995.

M.G. Allen, Z. Chen, J.B. Lee, Ajeet Rohatgi: "A Miniaturized High Voltage Solar Cell Array as an Electrostatic MEMS Power Supply," Journal of Microelectromechanical Systems, vol. 4, no. 3, pp. 102-108, 1995.

Ajeet Rohatgi: "Hydrogen in Silicon: A Discussion of Diffusion and Passivation Mechanisms," Solar Energy Materials and Solar Cells, 1995.

M. Begovic, R. Long, Ajeet Rohatgi, M. Ropp: "Roof-Installed PV System on the Olympic Swimming Pool at Georgia Tech," Proceedings of the 13th European Photovoltaic Solar Energy Conference and Exhibition, 1995.

Ajeet Rohatgi: "Photovoltaics: An Environmentally Clean Energy Option for the Next Generation," presented at both the DOE/National Geographic Kids Network Summer Institute and the 1995 Annual Meeting of the World Future Society, 41/42, pp. 159-169, 1995.

G. Augustine, R. Dhere, Nan Marie Jokerst, A. Rohatgi: "Concentration Dependent Near and Above Band Edge Absorption in Doped InP and Its Effect on Solar Cell Modeling," Journal of Applied Physics, vol. 78, no. 4, pp. 2666-2670, 1995.

Mark G. Allen, R. Arya, Z. Chen, J.B. Lee, A. Rohatgi: "A High Voltage Solar Cell Array as an Electrostatic MEMS Power Supply," IEEE Journal of Microelectromechanical Systems, vol. 4, no. 4, pp. 102-108, 1995.

M. Begovic, R. Long, Ajeet Rohatgi: "Photovoltaics in Architecture, The Design Construction and Monitoring of a Photovoltaic Power System on the Georgia Institute of Technology Aquatic Center," Proceedings of the 13th European Photovoltaic Solar Energy Conference and Exhibition, vol. 1, pp. 675-678, 1995.

G. Augustine, R. Dhere, N.M. Jokerst, Ajeet Rohatgi: "Concentration-Dependent Near and Above Band Edge Absorption in Doped InP and Its Importance in Solar Cell Modeling," Journal of Applied Physics, vol. 78, no. 4, pp. 2666-2670, 1995.

R.K. Ahrenkiel, H.C. Chou, N.M. Jokerst, S. Kamra, D.H. Levi, S.L. Lowrie, Ajeet Rohatgi, S.R. Stock: "Approach toward High Efficiency CdTe/CdS Heterojunction Solar Cells," Journal of Material Chemistry Physics, 1995, 1995.

Miroslav M. Begovic, R. Long, A. Rohatgi, M. Ropp: "Roof-Installed PV System on the Olympic Swimming Pool at Georgia Tech," Proceedings of the 13th European Photovoltaic Solar Energy Conference and Exhibition, Nice, France, 1995.

M. Cuzdinovic, C. Khattak, Ajeet Rohatgi, B.L. Sopori: "Characterization of HEM Multi-Crystalline Silicon Material for High Efficiency Solar Cells," Fifth Workshop on the Role of Impurities and Defects in Silicon Device Processing, Copper Mountain, CO, 1995.

Z. Chen, Ajeet Rohatgi: "Method for Passivating Silicon Devices at Low Temperature to Achieve Low Interface State Density and Low Recombination Velocity While Preserving Carrier Lifetime," U.S. Patent no. 5,462,898, 1995, no. 5, 1995.

A. Rohatgi, E. R. Weber, and L.C. Kimberling, "Opportunities in Silicon Photovoltaics and Defect Control in Photovoltaic Materials", Journal of Electronic Materials, vol. 22, no. 1, pp. 65-72, 1993.

A. Rohatgi, S. A. Ringel, R. Sudharsanan, P. M. Meyers, C. Liu, and V. Ramanathan, "Investigation of CdZnTe, CdMnTe, and CdTe Polycrystalline Films for Photovoltaic Applications", Solar Cells, vol. 27, no. 1, pp. 219-230, 1989.

A. Rohatgi and P. Rai-Choudhury, "Approach Toward 20% Efficient Solar Cells", IEEE Transactions on Electron Devices, vol. ED-33, no. 1, pp. 1-7, 1986.

A. Rohatgi, J. R. Davis, R. H. Hopkins, and P. G. McMullin, "A Study of Grown-In Impurities in Silicon by DLTS", Journal of Solid State Electronics, vol. 26, no. 11, pp. 1039-1049, 1983.

A. Rohatgi and P. Rai-Choudhury, "Process Induced Effects on Lifetime and Defects in Float-Zone Silicon", Journal of Electrochemical Society, vol. 127, no. 5, pp. 1136-1139, 1980.

Last revised February 2, 2023

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