Link: MIT researchers develop working prototype of infrared-absorbing solar cells

Made entirely of carbon and stable in open air, the transparent layer of carbon nanotubes and buckyballs can pick up infrared light, in addition to letting visible light through to conventional cells below. Although efficiency is only about .1%, it is expected to increase quickly. Because carbon is so cheap, the cost should be relatively low and therefore can go into use with a low efficiency. Every bit helps! Hopefully this can push solar energy to become a more powerful alternative.