- Comprehensive understanding of most photovoltaic technologies and the integration and use of PV materials and components in photovoltaic systems and solar cell arrays.
- Principal investigator (PI) developing heterojunction solar cells on 50 um thin Si wafers using laser processing.
- Performance and analysis of amorphous silicon in photovoltaic applications.
- Analysis of quantum efficiency and optical enhancement in amorphous silicon.
- Defining the status, trends, challenges and future of solar electricity from photovoltaics.
- Device measurements and analysis of thin film solar cells.
- Surface preparation and re-contacting on photovoltaic device performance and stability.
- Analysis and extraction of cell parameters from interconnected thin film modules.
- Reduce the cost of crystalline silicon solar cells by reducing both materials and manufacturing costs.
- Development of enhanced growth rate of nano-crystalline Si bottom cell by plasma enhanced chemical vapor deposition (PECVD) using novel gas mixtures.
- Maintain and critically evaluate solar simulator, and spectral response equipment.
- Consulting with the U.S. Photovoltaic industry on materials, applications, and technology developments.
Undisclosed University, 1993 - Present
Scientist, 2007 - Present
- Principal investigator on 3 year, $3.8 million (DOE) Department of Energy award to develop all-back contact heterojunction solar cells on 50 um thin Si wafers using laser processing.
- PI on DOE contract to develop enhanced growth rate of nanocrystalline Si bottom cell by plasma enhanced chemical vapor deposition (PECVD) using novel gas mixtures for a-Si/nc-Si micromorph tandem.
- PI of industry-funded programs to develop heterojunction solar cells on unique low cost UMG Si wafers.
- PI on 2 industry funded programs to evaluate accelerated life testing for encapsulated Cu(InGa)Se2 and organic module stability.
- Assist several companies in developing textured TCO for a-Si applications. Applying LBIC to evaluate uniformity of thin film solar cells and minimodules.
- Supervise Ph.D. and Masters students (Electrical Engineer, Physics, and Material Science).
- Teaching graduate class "Solar Energy Technology and Applications" for 10 years.
- Consult with U.S. Photovoltaic industry on materials, applications, and technology development.
Research Scientist, 1993 - 2007
- Responsible for optimization, analysis and characterization of thin film a-Si and CdTe solar cells.
- Developed model including field dependent collection and applied to a-Si and CdTe solar cell JV data to obtain fundamental transport properties.
- Developed analysis of QE to quantify optical enhancement due to light trapping in a-Si solar cells.
- Developed novel method to characterize SnO2/p contact in a-Si p-i-n solar cells.
- Designed and operated multi-chamber environmental stress test system to evaluate stability of thin film solar cells under controlled electrical bias, atmosphere, and thermal stress.
- Supervised Ph.D. and E.C.E. Masters degree students.
- Developed graduate class in "Solar Energy Technology and Applications."
IBM Corporation, Semiconductor Device Engineer, 1977 - 1982
- Modeling, testing, and design of analog and digital integrated circuit devices.
- Designed and tested a new stress independent integrated hall effect sensor.
Honors & Publications
- Edited edition of Handbook of Photovoltaic Science and Engineering
- Author and Co-Author of 90 publications: College text books and workbooks.
- Ph.D. Electrical Engineering, University of Delaware, Newark, DE
- M.E.E. Electrical Engineering, Cornell University, Ithaca, NY
- B.S.E.E. Electrical Engineering, Case Western Reserve University, Cleveland, OH