Feb 16 2010
Mitsubishi Electric Corporation has achieved photoelectric conversion efficiency of 14.8% in thin-film silicon PV cell measuring 5mm x 5mm. The sunlight energy that falls on solar cells is converted into electricity and the rate at which it is converted is called the photoelectric conversion efficiency. Higher conversion rates of the PV cells will yield higher output power.
Mitsubishi Electric has developed the thin-film silicon PV cell with triple junction structure for higher efficiency. The crystalline silicon PV modules are used in applications with limited spaces, for example, rooftops of residential homes, due to their greater photoelectric conversion efficiency rates.
Thin-film silicon PV cells use just 1% of silicon material that is used for crystalline silicon PV cells thus enabling to save costs as well as resources. Although the photoelectric conversion efficiency rates are lower in thin-film silicon PV cells when compared to crystalline silicon PV cells, it can be utilized for various large and mid-sized solar projects such as for factories, municipalities and electric power utilities. The projects are benefited through the lower product cost of thin-film silicon PV cells. The potential for use in other fields is more if the conversion efficiency rates can be increased in thin-film silicon PV cells.
At present, most of the thin-film silicon PV cells have single or double junction layers due to the difficulties to adjust the characteristics of each layer, though multiple junction layers offer higher conversion efficiency rates. Mitsubishi Electric, by using triple-junction layer, has achieved photoelectric conversion efficiency of 14.8% by utilizing key technologies.