Apparently there is a huge, no tremendous discovery in the domain of solar cell happening. SiOnyx is reportedly working on a ground breaking technology serendipitiously found by Harvard scientist Dr Mazur in late nineties. Apparently this black silicon (black, as in absorb all light) could absorb the visible light and the infrared and release much more energy when striked by a photon. Reportedly it would be 100 to 500 times more efficient than current solar cells.

More here:

http://www.masshightech.com/stories/2007/10/29/story10-Investor-millions-to-turn-black-to-light.html

http://www.xconomy.com/boston/2008/10/12/sionyx-brings-black-silicon-into-the-light-material-could-upend-solar-imaging-industries/