License issued for the functional principle of organic solar cells
From an Empa laboratory to a start-up in China
Flexible thin-film solar cells have good prospects to replace today’s rigid silicon-based solar cells, among other reasons because their production requires significantly fewer raw materials. Empa recently filed a patent for a novel type of organic solar cell. A former Empa researcher will shortly start manufacturing and marketing the new cells with his Chinese start-up company.
Bin Fan, a young Chinese researcher, worked at Empa and founded a company, Weihua Solar, in his home town of Xiamen.
The Empa patent concerns a novel thin-film solar cell in a “sandwich” construction. The real advance here is that the so-called active layer does not consist of rare and thus expensive elements but rather of synthetic organic dyes which have long been used in analogue photography for the emulsion of colour film. These absorb light extremely well, and they’re also efficient at converting it into electricity. Thanks to an Empa development, more specifically: ultra-thin salt layers which form a kind of interface between the two active layers. In this way, the flow of charge – the electric current – generated by incident sunlight is dramatically increased between the two layers, and thus the efficiency of the organic solar cell, as laboratory experiments have impressively shown.
From the lab to industrial scale – a giant leap
License issued even before the patent granted
| ||Frank Nüesch, head of Empa’s Functional Polymers Laboratory and Bin Fan’s thesis advisor, is pleased that the developments started at Empa are now making their way into practice.|
“For a researcher, this is a confirmation of his work.” Nüesch estimates that another five to ten years of development effort are necessary before the first solar cells designed around this new principle can be put on the market. Even so, he greatly admires the step taken by his former student. “That requires, among other things, a certain willingness to take on economic risks. We could never have done that in our laboratory.”