In a similar way to which snow falls to the ground, researchers at Fraunhofer ISE believe that titania can be applied to the backside of solar cells, allowing more sunlight to be absorbed by the cell. Highly reflective titania is applied to the backside of cells, in the technique, by being distributed into a liquid and then applied to cells. The liquid is allowed to fall, like snow, onto the cell. When dried, the coating boosts efficiency.
Fraunhofer ISE reports that the titania, suspended in liquid, forms a self-organized coating, leading to it efficiently reflecting light waves. Unlike conventional paints [the titania coating] contains no binders and is therefore highly reflective," writes Fraunhofer.
By being applied to the rear side of a solar cell, the titania coating simply reflects long-wave light that may pass through the c-Si active layer.
The method was developed by Angelika Basch, who was nominated for the Austrian Inventum Award. Basch has given it the name Snow Globe Coating.
It is currently being tested at Fraunhofer ISE by Christoph Goldschmidt and his team, by applying it to bifacial c-Si solar cells. Fraunhofer says that this simple method, carried out with the most basic laboratory equipment, can lead to a boost in conversion efficiency.
Fraunhofer ISE is currently seeking partners to commercialize the technology.