65% Efficient Solar Cells on the Horizon
June 21, 2010
Nanowire Solar Cell Research awarded €1.2million by Dutch Government ; project is targeted to help meet electricity demand in Southern Europe and North Africa.
Researchers at the University of Eindhoven (TU) are trying to develop solar cells with an efficiency of over 65% using nanotechnology. In Southern Europe and North Africa these new solar cells could generate a substantial portion of the European demand for electricity. The Dutch governmenthas reserved €1.2 million for the research.
An agency of the Ministry of Economic Affairs, will grant the €1.2 million to researchers Jos Haverkort, Erik Bakkers and Geert Verbong for their research into nanowire solar cells.
It is their expectation that, when combined with mirror systems, these solar cells can generate a sizeable portion of the European electricity demand in Southern Europe and North Africa.
Current III/V thin-film solar cells have an efficiency of around 40%, but they are very expensive and can only be applied as solar panels on satellites. By using mirror systems that focus one thousand times they can now also be deployed on earth in a cost-effective manner.
The TU/ researchers expect that in ten years their nano-structured solar cells will attain an efficiency of more than 65%. Scientist, Jos Haverkort said "If the Netherlands wants to timely participate in a commercial exploitation of nanowire solar cells, there is a great urgency to get on board now."
The research is conducted together with Philips MiPlaza. They think that nanotechnology, in combination with the use of concentrated sunlight through mirror systems, has the potential to lead to the world’s most efficient solar cell system with a cost price lower than 50 cent per Watt peak.
In comparison: for the present generation of solar cells that cost price is €1.50 per Watt peak.
Nanowires make it possible to stack a number of subcells (junctions). In this process each subcell converts one colorof sunlight optimally to electricity. The highest yield reported until now in a nanowire solar cell is 8.4%. Haverkort commented, “We expect that a protective shell around the nanowires is the critical step towards attaining the same efficiency with nanowire solar cells as with thin-film cells." Haverkort thinks that at 5 to 10 junctions he will arrive at an efficiency of 65%.
Furthermore, the researchers expect considerable savings can be made on production costs, because the rapid growth of nanowires on a cheap silicon substrate results in a lower cost of ownership of the growth equipment. Also, the combination of the mirror systems with nanotechnology will imply an acceptable use of the scarce and hence expensive metals such as gallium and indium.