More efficient solar cell developed

Abstract

single-junction gallium arsenide (GaAs) solar cell that converts sunlight to electricity with 28.1% efficiency has been developed by Varian Associates in Palo Alto, Calif. The conversion efficiency is the highest yet achieved by a GaAs solar cell. In 1986, Varian had produced a single-junction GaAs solar cell with 26.3% conversion efficiency. The GaAs cell, which measures 5 mm X 5 mm, has applications in both terrestrial power systems and orbiting satellites, the company says. Small increases in efficiency can dramatically reduce operating costs in both applications, according to Alan J. Bennett, Varian's vice president of research. A one percentage point efficiency gain can significantly increase the number of communication channels on a satellite, while reducing construction expenses by millions [of dollars], Bennett says. He points out that silicon cells now in use on satellites have conversion efficiencies of about 14%. Additionally, the GaAs cells are more resistant than traditional silicon cells...