A Step Closer To The Optimum Solar Cell
An anonymous reader writes "Besides cost, solar cell efficiency is the second most critical criteria. Scientists from Berkeley Lab and other institutions, have announced a new solar cell material that may be able to achieve an extraordinary efficiency of about 50 percent -- twice the amount of the current record holder."
The ROI (for retail and manufacture cost) and the Enviromental impact of production is addressed.
Granted the source is an RE magazine, but they do list references on some of the studies if you want to follow up.