Twenty-four percent efficient silicon solar cells with double layer antireflection coatings and reduced resistance loss

Abstract

Significant performance increase for silicon solar cells is reported. This has been achieved by a combination of several mechanisms. One is the reduction of recombination at cell surfaces using atomic hydrogen passivation of silicon/silicon dioxide interfaces. Joule resistive losses in the cell have been reduced by a process which allows different thickness for fine and coarse features in the top cell metallization. Finally, reflection losses have been reduced by the use of a double layer antireflection coating. For successful incorporation, this required the development of techniques for growing the surface passivating oxide very thin, without reducing its passivation qualities. The cells display a monochromatic light energy conversion efficiency of 46.3% for 1.04 μm wavelength light, also the highest ever for a silicon devices.