World's Highest Level Conversion Efficiency over 11.4%; Tanaka Precious Metals Exclusively Supply Ruthenium Dye for Dye-Sensitized Solar Cells


Tokyo, - Tanaka Holdings Co., Ltd. (a company of Tanaka Precious Metals) today announced that Tanaka Kikinzoku Kogyo K.K., which operates the Tanaka Precious Metals' manufacturing business, will begin exclusively providing the CYC-B11 ruthenium complex dye with a conversion efficiency over 11.4% -one of the world's highest level for dye-sensitized solar cells(*1).

The product is a ruthenium complex dye being used as a light-harvesting material to perform photon-to-current conversion in dye-sensitized solar cells which hailed as the next generation of solar cells. Dye-sensitized solar cells using the product achieve efficiency over 11.4 % for converting light energy into electricity, which is the world's highest level for dye-sensitized solar cells.

The ruthenium complex dye was developed by Professor Chun-Guey Wu and post-doctoral researcher Chia-Yuan Chen at National Central University, Taiwan (No.300Jhong-Da Rd.,Jhong-Li, Taoyuan, Taiwan 32001 R.O.C.), and the efficiency of the dye was evaluated by the team of Professor Michael Gratzel, who is a world authority on dye-sensitized solar cells, at Ecole Polytechnique Federale de Lausanne, Switzerland. Tanaka Precious Metals has independently obtained a sales license from National Central University, Taiwan, to exclusively manufacture and sell the dye.

New dye's light absorption approaches the sunlight to enhance conversion efficiency

Dye-sensitized solar cells utilize a mechanism in which electric power is generated when light shines on the dye, and have been developed as one of next-generation solar cells that enables lower power generation costs. In dye-sensitized solar cells, one of the key elements for reaching high conversion efficiency is the dye that absorbs light and much research and development has been conducted on ruthenium complex dyes as a stable dye with high performance.

The ruthenium complex dye developed by National Central University, Taiwan, exhibits the capacity to absorb more visible sunlight (*2), reaching a remarkable conversion efficiency of over 11.4%. Tanaka Precious Metals, as a company for manufacturing and selling the metal related products, will exclusively manufacture and sell the dye. It is making a big effort on developing high-yield manufacturing processes and recycling ruthenium metal aiming at reducing the dye cost through the practical and extensive application of the technology to stable supply and effective utilization of ruthenium metal in the dye.

Toward widespread use of dye-sensitized solar cells

Manufacturing processes for dye-sensitized solar cells do not require vast facilities such as highly energy-consuming vacuum equipment and clean rooms. The electrodes for dye-sensitized solar cells can be printed conveniently under ambient environment. These features enable significantly lower manufacturing costs compared to currently widespread crystalline silicon solar cells. Furthermore, not only can the color of the cells be freely changed by changing the dye color but also providing conversion efficiency even with indoor light, it is possible to fabricate thin, lightweight, transparent, and flexible solar cell modules (*3) by using plastic substrate. Thus, it is expected to have the design-oriented applications such as attachment to the surface of windows, clothes and portable electronic devices. Tanaka Precious Metals estimates that the use of these dye-sensitized solar cells starting to spread from 2013 and they will account for 5% to 10% of the overall solar cell market by 2015.

In manufacturing and sales, Tanaka Precious Metals has also obtained a license from National Central University, Taiwan, to sell the CYC-B1 ruthenium complex dye with conversion efficiency over 9.5%. The company aims to push the annual sales of our ruthenium complex dyes to 300 million yen by 2015. We will continue putting efforts to reduce the manufacturing costs, and establish a manufacturing system aimed at the practical applications of this technology.

Company release:
http://pdf.japancorp.net/english/clientreports/4294/1226_EN.pdf

(*1) This ruthenium complex dye and cell conversion efficiency value were announced in an international scientific journal, ACS nano (volume 3, page 3103-3109), published in September 2009.

(*2) The wavelength range of visible light is approximately 400 to 750 nanometers (one billionth of a meter).

(*3) Solar cell module: Several solar cells, the fundamental units, are aligned and packaged in an array to form a module.

Tanaka Holdings Co., Ltd. (Holding company of Tanaka Precious Metals)

Headquarters: 22F, Tokyo Building, 2-7-3 Marunouchi, Chiyoda-ku, Tokyo

Representative: Hideya Okamoto, President & CEO

Founded: 1885

Incorporated: 1918

Capital: 500 million yen

Employees in consolidated group: 3,456 (FY2010)

Net sales of consolidated group: 891.0 billion yen (FY2010)

Main businesses of the group: Manufacture, sales, import and export of precious metals (platinum, gold, silver, and others) and various types of industrial precious metals products. Recycling and refining of precious metals.

Website: www.tanaka.co.jp

Tanaka Kikinzoku Kogyo K.K.

Headquarters: 22F, Tokyo Building, 2-7-3 Marunouchi, Chiyoda-ku, Tokyo

Representative: Hideya Okamoto, President & CEO

Founded: 1885

Incorporated: 1918

Capital: 500 million yen

Employees: 1,532 (FY2010)

Sales: 865.4 billion yen (FY2010)

Businesses: Manufacture, sales, import and export of precious metals (platinum, gold, silver, and others) and various types of industrial precious metals products. Recycling and refining of precious metals.

Website: pro.tanaka.co.jp

About the Tanaka Precious Metals

Established in 1885, the Tanaka Precious Metals has built a diversified range of business activities focused on the use of precious metals. On April 1, 2010, the group was reorganized with Tanaka Holdings Co., Ltd. as the holding company (parent company) of the Tanaka Precious Metals. In addition to strengthening corporate governance, the company aims to improve overall service to customers by ensuring efficient management and dynamic execution of operations. Tanaka Precious Metals is committed, as a specialist corporate entity, to providing a diverse range of products through cooperation among group companies.

Tanaka Precious Metals is in the top class in Japan in terms of the volume of precious metal handled, and for many years the group has developed and stably supplied industrial precious metals, in addition to providing accessories and savings commodities utilizing precious metals. As precious metal professionals, the Group will continue to contribute to enriching people's lives in the future.

The eight core companies in the Tanaka Precious Metals are as follows.

- Tanaka Holdings Co., Ltd. (pure holding company)

- Tanaka Kikinzoku Kogyo K.K.

- Tanaka Kikinzoku Hanbai K.K.

- Tanaka Kikinzoku International K.K.

- Tanaka Denshi Kogyo K.K.

- Electroplating Engineers of Japan, Limited

- Tanaka Kikinzoku Jewelry K.K.

- Tanaka Kikinzoku Business Service K.K.

Press inquiries

Global Sales Dept., Tanaka Kikinzoku International K.K. (TKI)

e-mail: tki-contact@ml.tanaka.co.jp

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