Showa Denko K.K. (SDK) Offers Samples of Titania Paste for Use in Solar Cell Electrode

	
Tokyo, Japan, Sept. 16, 2003 - (JCN Newswire) - Showa Denko K.K. (SDK)
has developed titanium oxide paste that can be formed into a film at low
temperature, for use in electrodes of a dye-sensitized solar cell (DSC).
Samples of the new product (trade name: SP-X) are being offered.

In DSC, a flow of excited electrons, which results from the absorption
of sunlight by dye, is led to electrodes made of semiconductor
particles, including titanium oxide, thereby causing electromotive force
(photon-to-electron conversion). Compared with conventional
silicon-based solar cells, DSC is easier to fabricate and can be
fabricated at lower cost.

DSC can be developed in two different directions. One is as a
replacement of conventional silicon-based solar cells, using a glass
substrate. The other will use flexible resin substrate for such portable
goods applications as hats and umbrellas. It can also be used in blinds,
tents and automobiles.

Titanium oxide particles play a key role in DSC, ensuring effective use
of the flow of electrons resulting from the absorption of sunlight by
dye. 

Since heat treatment of titanium oxide particles at nearly 500 C is
required to ensure sufficient photon-to-electron conversion, glass has
been used as substrate for electrodes. However, use of a resin film
substrate has been studied because it will offer advantages in terms of
weight, flexibility and portability. The problem has been that a
substrate made from resins allows heat treatment of titanium particles
at only around 150 C, meaning that sufficient photon-to-electron
conversion is not ensured.

And, in forming a titanium oxide film on a resin film substrate,
coating/drying of titanium oxide paste is the most convenient process
compared with such alternatives as electro-deposition (electrophoresis)
and application with pressure. 

SDK has therefore developed "SP-X" titanium oxide paste. This new
technology enables low-temperature formation of a titanium oxide film
that can be used with a resin film substrate for DSC. Specifically, the
new technology has the following characteristics:

1. Nano-scale control of primary particle sizes (any size between 10 and
500 nm) 
2. Specially designed titanium oxide structure that facilitates dye
adsorption on titanium oxide particles and electron flow / electrolyte
diffusion inside the titanium oxide film 
3. Combination of titanium oxide particles with different sizes to
effectively use long-wave light 
4. Optimized blending of organic binders 

SP-X will be produced by Showa Titanium Co., Ltd., a wholly owned
subsidiary of SDK located in Toyama City, Toyama Prefecture. The company
is already producing a variety of titanium oxide products for such
applications as dielectric, photocatalyst, and ultraviolet shield. SDK
is planning to sell JPY 7 billion of titanium oxide products in 2010.

In line with the medium-term consolidated business plan named the
"Sprout Project," SDK will promote the titanium oxide business centering
on the electronics and environment-related markets.


About Showa Denko K.K.

Showa Denko is a major manufacturer and marketer of chemical
products serving a wide range of fields ranging from heavy industry to
the electronic and computer industries. the company makes petrochemicals
(ethylene, propylene), aluminum products (ingots, rods) electronic
equipment (hard disks for computers), and inorganic materials (ceramics,
carbons). The company has overseas operations and a joint venture with
Netherlands-based Montell and Nippon Petrochemicals to make and market
polypropylenes. In March 2001, SDK merged with Showa Denko Aluminum
Corporation to strengthen the high-value-added fabricated aluminum
products operations, and is today developing next-generation optical
communications-use wafers. For further information, please visit the
Showa Denko K.K. home page at: www.sdk.co.jp/index_e.htm
http://www.sdk.co.jp/index_e.htm>