May 31, 2007

Tokyo, Japan: Mitsubishi Electric Raises Efficiency of Multi-Crystalline Solar Cells

Mitsubishi Electric has achieved a new record photoelectric conversion efficiency rate of 18.0% for 150mm square multi-crystalline silicon solar cells, an improvement of 1.2% over the company's previous level. These results have been confirmed by the National Institute of Advanced Industrial Science And Technology (AIST), a public verification agency

Mitsubishi achieved the 18% efficiency rate by adding a low reflectivity surface texture on the multi-crystalline silicon as well as developing a process to print electrodes on the surface of the silicon (metallization) and reducing shade loss of front grid electrodes. In the same surface area as previous products, Mitsubishi achieved a 7% greater electric output, making it suitable for even smaller installations such as narrow roofs.

The main features of the cell include:

Using a nano-sized mask material, the Reactive Ion Etching (RIE) method uses highly reactive ions generated by RF plasma, letting ions precisely etch the target materials. This decreases reflectivity from the texturized surface of the multi-crystalline silicon, increasing the amount of absorbed light4.

New metal electrode material reduces metallization time by approximately half that of previous models, and sustains electrical performance of crystalline.

Using modified screens and front metal electrodes Mitsubishi reduced shading loss of front grid electrodes by 40% compared with our conventional cells

Mitsubishi will begin introducing this technology into the company's mass produced photovoltaic modules after the end of 2007. Pairing this with the company's power module, which the company says has the industry’s highest energy conversion efficiency, will increase the company's output of solar power systems.

Further details about: Mitsubishi Electric