Sharp Compound Solar Cell Equals Conversion Efficiency Record Of 43.5%
Sharp has achieved what it claims is the world's
highest solar cell conversion efficiency of 43.5% using a concentrator
triple-junction compound semiconductor solar cell.
The result is reported for May 30th, 2012, for concentrator solar cells at
the research level, based on a survey by Sharp.
The conversion efficiency was confirmed by the
Fraunhofer Institute for Solar Energy (ISE) in April 2012 under a
light-concentrating magnification of 306 times. With a cell surface of
approximately 0.167 cm2, the conversion
efficiency is the same as that achieved by U.S. firm Solar Junction in March
2011.
These III-V based solar cells are used in a lens-based
concentrator system that focuses sunlight on the cells to generate electricity.
Compound solar cells utilise photo-absorption layers
made from compounds consisting of two or more elements, such as indium and
gallium. The basic structure of this latest triple-junction compound solar cell
uses Sharp's proprietary technology that enables efficient stacking of the
three photo-absorption layers, with InGaAs as the bottom layer.
To achieve this latest increase in conversion
efficiency, Sharp capitalised on the ability of this cell to efficiently
convert sunlight collected via three photo-absorption layers into electricity.
The firm also optimised the spacing between electrodes on the surface of the
concentrator cell and minimised the cell's electrical resistance.
This latest Sharp breakthrough came about through
research and development efforts that are part of the "R&D on Innovative
Solar Cells" project promoted by Japan's New Energy and Industrial Technology
Development Organisation (NEDO). NEDO is one of Japan's largest public
management organisations for promoting research and development as well as for
disseminating industrial, energy, and environmental technologies. ISE also
participates on this project.
Their superior conversion efficiency make compound
solar cells ideal for use in space satellites, which is their primary
application.
Sharp's aim for the future is to apply this latest
development success into concentrator photovoltaic power systems that can
efficiently generate electricity using small-surface-area solar cells and make
them practical for terrestrial use.
