4 June 2012 Sharp develops concentrator solar cell with efficiency of 43.5%
Japan's Sharp Corp has used a concentrator triple-junction III-V compound semiconductor photovoltaic cell to achieve a solar energy conversion efficiency of 43.5%,equaling the record for concentrating conversion efficiency set in March 2011 by Solar Junction of San Jose,CA,USA,a manufacturer of III-V multi-junction solar cells for concentrated photovoltaics(CPV).
Measurement of the value of 43.5%was confirmed in April by the Fraunhofer Institute for Solar Energy Systems(ISE)in Freiburg,Germany for a cell surface of about 0.167cm2 under a light-concentrating magnification of 306x.One of several organizations around the world that officially certifies efficiency measurements in solar cells,ISE is one of seven European research establishments collaborating with Japanese partners in the 42-month-long EU-funded project'NGCPV:A new generation of concentrator photovoltaic cells,modules and systems',which began in June 2011.
The basic structure of the latest triple-junction compound solar cell uses Sharp's proprietary technology enabling efficient stacking of the three photo-absorption layers,with InGaAs(indium gallium arsenide)as the bottom layer.
To achieve the latest increase in efficiency,Sharp capitalized on the ability of this cell to efficiently convert sunlight collected via three photo-absorption layers into electricity.Sharp also optimized the spacing between electrodes on the surface of the cell and minimized the cell's electrical resistance.
Sharp says that itslatest development arose through R&D efforts that are part of the'R&D on Innovative Solar Cells'project promoted by Japan's New Energy and Industrial Technology Development Organization(NEDO),which is one of the country's largest public management organizations for promoting R&D as well as for disseminating industrial,energy,and environmental technologies.
Because of their high conversion efficiency,compound solar cells have been used primarily for space satellites.However,Sharp's aim for the future is to apply this latest development in CPV power systems that can efficiently generate electricity using small-surface-area solar cells and make them practical for terrestrial use.
