Photovoltaics (PV) are hot news in the speciality chemicals industry right now. During November alone, DuPont Apollo opened a silicon-based thin-film PV module facility in China, while Evonik Industries began construction of an integrated production plant for monosilane and fumed silica in Japan as a first move into PVs and Dow signed an alliance in the field with the California Institute of Technology (Caltech).

The new facility at Shenzhen from DuPont’s wholly owned DuPont Apollo subsidiary covers 50,000 m2 and will have up to 50 MW/year of capacity for thin-film-on-glass PV modules for the domestic Chinese market. DuPont added that the facility is unique as “the first total solar energy solution provider in China”, not least because local R&D capabilities were combined with manufacturing.

Thin-film PV modules should be the fastest growing segment of the solar module industry, according to DuPont. Indeed, the company expects to generate sales of over €650 million/year in the field by 2012.

They can help to reduce the cost of producing solar energy, are suited to commercial rooftops, building façades and large-scale solar farm applications, while generating more wattage output under diffuse lighting conditions. They consume only about 0.5% of the silicon metal in traditional crystalline silicon solar cells.

Meanwhile, Evonik and its partner Taiyo Nippon Sanso (TNSC), a supplier of industrial and speciality gases, have laid the cornerstone for their new €150 million plant at Yokkaichi.

Under a long-term supply agreement, Evonik will supply TNSC with monosilane for use in thin-film PVs, flat screens and semiconductors electronics, while silicon tetrachloride generated during monosilane production will be processed into fumed silica for use in plastics, paints, coatings, adhesives and sealants.

Evonik is the largest global producer of chlorosilanes and a major producer of monosilanes, both of which are key in solar energy production. The company developed the monosilane production process that will be used at Yokkaichi itself and uses this at its own plant at Rheinfelden, Germany. It expects monosilane demand to grow by 20%/year to 2020.

Finally, Dow and Caltech have signed a four-year research collaboration in solar energy that will be one of Dow’s largest externally funded research agreements. The aim is to develop low cost, highly efficient PV materials by combining Dow’s capabilities in copper, indium, gallium and selenium (CIGS) materials with Caltech’s research in the field.

Initial joint research work will focus on direct band gap materials from earth-abundant elements that incorporate elements that are less expensive and more commonly available than those used in today’s thin film PV semiconductors. Professor George Agyros of Caltech said that using these materials could “provide new technology options and open new areas of design space.”

Recently, Dow announced its first building-integrated PV product, the Dow Powerhouse solar shingle, which uses thin CIGS-based films to convert sunlight into electricity. This was named one of the ‘50 Best Inventions of 2009’ by Time magazine.

The Powerhouse solar shingle integrates low-cost, thin-film CIGS PV cells into a proprietary roofing shingle design, which represents a multi-functional solar energy-generating roofing product that can be installed at low cost by roofing contractors with no specialised knowledge of solar array installations. It should be available on the market in 2010.

Dow claims that the use of CIGS offers “lower cost, easier installation and a dramatically improved aesthetic” because, unlike silicon, these materials can be incorporated directly into flexible products like Powerhouse shingles. The key challenge in developing their further use in PV materials, is the high cost and relative scarcity of some of the elements used in this and other thin film semiconductors.