Updates‎ > ‎

2019-04-10. Marrying two types of solar cells draws more power from the sun.

posted Apr 13, 2019, 4:52 PM by Alan Gould
By Robert F. Service, Science Magazine. [https://www.sciencemag.org/news/2019/04/marrying-two-types-solar-cells-draws-more-power-sun] For GSS Energy Use chapter 10. Excerpt: ORLANDO, FLORIDA—The promising solar cell materials called perovskites need a partner. Researchers marry a layer of perovskite, which absorbs high-energy blue photons in sunlight, with standard silicon, which gobbles up lower-energy light. In theory, such tandem cells should deliver a double dose of power, with electricity coming from both layers. But building two complete solar cells, one atop the other, adds cost and other challenges. Last week, a team reported advancing a potentially simpler, cheaper way to make a tandem. The team's perovskite converts light instead of generating current, transforming blue photons to near-infrared (near-IR) photons, which the silicon cell below then turns into electricity. The researchers say the design could boost the efficiency of silicon solar cells by nearly 20%. ...Silicon dominates the solar industry not because it's the best solar converter, but because it's serviceable and relatively cheap. Still, manufacturers must use expensive clean rooms to purify and prepare it. Perovskites, in contrast, are easy to coax into a thin, powerfully light-absorbing layer. Most perovskites are best at absorbing blue light, so they must be paired with other materials to snag the full solar spectrum. The solar industry is racing to commercialize perovskites by placing them atop conventional silicon modules, which discard much of the energy in bluer light photons, releasing it as heat rather than electric current....