Solar pays its way

Alejandro Briseno of the University of Massachusetts Amherst and colleagues have stacked up nanoscopic "coins" to construct a new type of solar cell that can efficiently harvest light like blades of grass in a lawn and generate electrical energy. The long-sought polymer architecture they have developed can offer high power-conversion efficiency. The technique is simple, inexpensive and applicable to a library of donor and acceptor compounds that are commercially available, Briseno says.