New Solar Cells Researchers in Berkeley Lab's Materials Sciences Division (MSD), working with crystal-growing teams at Cornell University and Japan's Ritsumeikan University, have learned that the band gap of the semiconductor indium nitride is not 2 electron volts (eV) as previously thought, but instead is a much lower 0.7 eV. The serendipitous discovery means that a single system of alloys incorporating indium, gallium, and nitrogen can convert virtually the full spectrum of sunlight-from the near infrared to the far ultraviolet-to electrical current. If solar cells can be made with this alloy, they promise to be rugged, relatively inexpensive-and the most efficient ever created.