Sharp Corp., an Osaka, Japan-based producer of solar and electronic products, has developed mass-production technology for triple-stacked thin film solar cells.
The company turned a conventional two-active-layer structure (amorphous silicon plus microcrystalline silicon) into a triple-junction structure with amorphous silicon (two active layers) and microcrystalline silicon (single active layer). This new structure boosts cell conversion efficiency from 11% to 13% and module conversion efficiency from 8.6% to 10%, the company says.
According to Sharp, the shift from a two-layer to a three-layer structure would normally demand an increase in production equipment, but these new solar cells can be fabricated on the same equipment as conventional, two-layer cells. Mass production is slated to begin in May of 2007 at the company's Katsuragi plant in Nara Prefecture, Japan.