Japanese step up research and development as solar cell competition heats up

In the early years of the solar industry the Japanese led the way. But interest in that nation’s solar cells has cooled, reports Nikkei as the market for German products took off.
Sharp was the largest producer of solar cells in 2006. It slipped to second place in 2007 and was fourth in 2008. The other two Nipponese giants, Sanyo and Mitsubishi have fared even wore, dropping out of the top ten entirely.
Now the industry is led by Germany’s Q-Cells SE of Germany, with US based First Solar and China’s Suntech Power Holdings leading the field.
This is an open market in which any newcomer can make rapid progress, because solar cells are relatively simple structures. They can be made by any manufacturer with the right equipment and with the necessary backing. Which probably explains the lack of any British vendors in the leading pack
The Japanese have responded in a manner which their British counterparts would do well to emulate. Or try at least. Sharp is working on a raft of new technologies that will boost the efficiency of energy conversion. At the moment, only 15 per cent of solar energy can be created by mainstream crystalline solar cells. Mono and poly - crystalline cells account 90 per cent of solar cells shipped by Japanese makers in 2008.
Now that Crystalline solar cells are regarded as commodities, the Japanese vendors are struggling to compete with cheap rivals in other nations with low labour costs.
So they are raising the bar with new thin-film silicon versions. If the technology works, solars cells could be made cheaply as smaller amounts of silicon are needed. But thin-film silicon solar cells have lower conversion efficiencies of around 10 per cent.
Sanyo and Nippon are looking to solve the problem with two thin layers of silicon.
Other vendors use CIGS solar cells, made from a combination of copper, indium, gallium, and selenide. But these too are poor electrical performers, with conversion efficiencies of around 10 per cent. Showa Shell Solar and Honda Soltec are two of the many Japanese companies working to develop more efficient CIGS solar cells.
Mitsubishi Chemical Holdings, meanwhile, is developing organic thin-film solar cells, while Sony and Fujikura are working on dye-sensitized solar cells.
These new varieties are expected to substantially lower production costs, but they are not yet efficient or reliable enough to be used widely.
In the long run, the manufactures have more ambitious targets. Organic and dye-sensitised devices will eventually develop to provide a more efficient alternative to crystalline silicon. One estimate says the cost of generating electricity with these next-generation technologies will be roughly on par with commercial electricity rates.
Perhaps British scientists should gear up for a target further into the future. The end game is produce power using quantum dot cells, which have a theoretical conversion rate of 60 per cent.
The challenge is to develop multi-junction solar cells, which include layers of materials that absorb light of different wavelengths.
There’s a number of development problems to be overcome first. And therein lies the opportunities for Britain’s scientists.