Miguel A. Contreras

E-mail: Miguel.Contreras@nrel.gov

Miguel A. Contreras is currently a Supervisor/Senior Scientist at the National Renewable Energy Laboratory (NREL). Since joining NREL in 1990, Dr. Contreras has worked in the research and development of thin-film materials for photovoltaic applications. His work has resulted in numerous publications (over 150 co-authored papers), six US patents related to copper-indium-gallium-diselenide (CIGS) thin-film solar cells, several world-records in energy conversion efficiency for this technology and earned him several recognitions and awards. Among these honors, Dr. Contreras is the Winner of the 1993 “Best of What’s New” award from Popular Science Magazine for record thin-film solar cell performance; the Most cited physicist in 2001 and ranked 7th in the Top Ten list of most cited scientific works by “Science Watch” (http://www.sciencewatch.com/sept-oct2001/sw_sept-oct2001_page6.htm); elected as a “Fellow” of the 2006 World Technology Network for contributions to the field of solar energy (http://www.wtn.net/2006/summit/shortlisted.html); the Winner of the HENAAC 2008 Outstanding Technical Achievement award for contributions to the field of renewable energy technologies (http://www.greatmindsinstem.org/media/pressreleases/2008HENAACAwardWinners.pdf); and is ranked at the top 10 most cited authors and author of the most cited paper in the area of Energy and Fuels for the1999-2008 decade (http://sciencewatch.com/ana/fea/08novdecFea/).

Dr. Contreras earned a BSEE degree at the Universidad de Santiago de Chile (’83), a MSEE at the University of Wisconsin-Madison (’90) and a Ph.D. in Materials Science at the Colorado School of Mines (’96). He is a member elect of the World Technology Network; member of the Editorial Board for Progress in Photovoltaics; member of the Advisory Board for Energy Research News; member of the Materials Research Society and a member of the Institute of Electric and Electronic Engineering (IEEE).

Abstract

Photovoltaic Materials: past, present and future

For decades now Silicon has been the workhorse of the photovoltaic business and still remains a relevant material for the generation of electricity using sunlight. However, due to the pressing need to further lower the cost of PV power, alternative materials have been and will continue to be developed to make solar electricity more affordable and competitive with traditional forms of generating electrical power. There are some basic physical properties that qualify a given semiconductor material for photovoltaic applications. Here, parameters such as energy gap, conductivity type, carrier concentrations, mobility, etc. are just a few physical properties that can indicate feasibility and viability of a given material. Nevertheless, not all materials that work as photovoltaic absorbers will become commercially viable and in fact high energy conversion efficiency is just one requirement to succeed in the marketplace. A more important figure is perhaps the fabrication cost, commonly expressed in $/Watt, that is associated with the manufacturing of PV modules that will determine how competitive the technology can be. In this presentation an outline of the energy scenario in the United States is given and an overview of solar cell technologies is presented emphasizing their physics, technological strengths and weaknesses, current manufacturing methods, and their prospective as viable and economical solutions to the global energy and environmental challenges we face today.