Mitsubishi Electric Develops Solar Cells with 18% Conversion Efficiency

Mitsubishi Electric Corporation of Japan announced on May 31, 2007 that it has achieved the world's highest photo-electricity conversion efficiency --18 percent -- in practical applications of its 150mm square multi-crystalline silicon photovoltaic (PV) cell. The new PV cell has the same surface area as previous products, but generates 7 percent more electricity, enabling greater solar power generation in more limited space. The company will introduce this technology into its PV modules for commercialization after the end of 2007.

As PV cell production increases due to demand for these eco-friendly, renewable-energy devices, the demand for silicon used in PV cells has far outstripped the supply worldwide. Thus, more effective power generation from smaller amounts of silicon is needed. Mitsubishi Electric achieved the high conversion efficiency by using the following technologies:

1. The Reactive Ion Etching (RIE) method, which lowers the reflectivity of the cell surface and increases the amount of light absorbed;
2. New material for metal electrodes that reduces by half the time it takes for the electrode to become metallized, compared to previous models, and sustains electrical performance of the crystals;
3. Modified screens and front metal electrodes that reduce shading loss of front-grid electrodes by 40 percent compared with previous models.

Mitsubishi Electric plans to present this technology at the Fukuoka 17th International Photovoltaic Science and Engineering Conference in December 2007.

http://global.mitsubishielectric.com/bu/solar/products/pdf/PVe_0531.pdf

Posted: 2007/11/07 01:58:38 PM
Japanese version