The sawtooth cover slide

A novel cover slide is reported which increases solar cell output by reducing the reflection of light from the cover slide surface and by redirecting incident light so that none falls on the collection grids of the cell. The new cover slide is fabricated with a sawtooth surface having a periodicity equal to that of the solar cell grids. This configuration refracts the light so that it is directed onto the semiconductor surface between the grid lines. Conventional grid patterns obstruct 7-10 percent of the light incident on the cell; at least half of this loss has been recovered by using the sawtooth cover slide. In addition, surface reflection from the conventional coated cover slide is suppressed by presenting a second surface to any light reflected at the first plane of contact. This double reflection results in a greater reduction of the reflection loss from the cover slide than does an antireflection coating on a flat surface.