New photovoltaic technology first reported almost a year ago is emerging that is nearly five times more efficient than current technology. It uses silicon, like normal crystalline cells, but a unique fabrication process uses only about 2% of the amount of silicon that normal cells use and the material is created in a flexible film. The cells are not only five times as efficient, they use very little of the expensive silicon.
http://media.caltech.edu/press_releases/13325
podcast: http://images.caltech.edu/podcasts/research_news/atwater_podcast.mp3