The record efficiency of AM 1.5 ("standard sunlight", unconcentrated by lenses) solar cells has been stuck below the theoretical maximum for many years.

This new paper shows a way to make a substantial improvement in efficiency by understanding the physics better. Briefly, the most efficient solar cell needs to be made from materials that are also good light emitters and you need to design the cell with light emission in mind.

http://www.energyboo...fficiency-ratings

The full paper is here: http://arxiv.org/abs/1106.1603

Cheers,
Scott.

He's a great salesman. ;-) He glosses over lots of issues though.

Carbon-based nano materials do have lots of promise, but they're years away from being practical for many applications. There are still far too many things that aren't known and aren't controllable enough at the moment.

http://spectrum.ieee...ronics-unzipped/0

http://www.smarterte...Future-After-All/

Cheers,
Scott.