To make solar cells more efficient, sprinkle them with silver
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/seeing-red-0
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/economist-london
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solar-energy
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/energy-technology
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solar-cells