In ordinary photovoltaic cells, lots of sunlight goes to waste as it heats up the cell. New results suggest that solar cells made from nanocrystals can trade this wasteful heating for an electricity-generating boost.
Theoretical calculations indicate that nanocrystal-based solar cells could convert 60 percent of sunlight into electricity, say Richard D. Schaller and Victor I. Klimov of Los Alamos (N.M.) National Laboratory. The best solar cells today operate at an efficiency of about 32 percent.
Schaller and Klimov describe their results, the first observations of a long-sought cue ball effect in nanometer-scale crystals, in the May 7 Physical Review Letters.
The work is "an important scientific advance," says Arthur J. Nozik of the National Renewable Energy Laboratory in Golden, Colo. He was the first scientist to propose that nanocrystals, sometimes called quantum dots (SN: 3/6/04, p. 157: Available to subscribers at Quantum sentine