Sharp’s III-V Solar Cell Is The Brightest At 36.9%
The III-V compound semiconductor solar cell has broken efficiency barriers.
Sharp Corporation has achieved what it claims is the world’s highest solar cell conversion efficiency of 36.9% using a triple-junction semiconductor solar cell.
Compound solar cells utilise photo-absorption layers made from compounds consisting of two or more elements, such as indium and gallium. Because of their high conversion efficiency, compound solar cells have been used primarily on space satellites.
Since 2000, Sharp has been pursuing research and development of a triple-junction compound solar cell that achieves high conversion efficiency by stacking three photo-absorption layers. In 2009, Sharp succeeded in improving cell conversion efficiency to 35.8% based on proprietary technology that enabled efficient fabrication of a stacked triple-layer structure with InGaAs as the bottom layer.
This latest increase in conversion efficiency was achieved by improving the maximum power output of the solar cell by reducing the resistance of the junction areas necessary to connect the solar cell layers in series.
Sharp achieved this latest breakthrough as a result of a research and development initiative promoted by Japan’s New Energy and Industrial Technology Development Organisation (NEDO) on the theme of “R&D on Innovative Solar Cells."
NEDO is Japan’s public management organization for promoting research and development as well as for disseminating industrial, energy, and environmental technologies.
The measurement of 36.9% sets a new record for the world’s highest non-concentrating conversion efficiency, and was confirmed at the National Institute of Advanced Industrial Science and Technology (AIST), who measured a cell surface of approximately 1 cm2.
In the future, processes for transferring ultra-thin photovoltaic layers onto film substrates will make lightweight, flexible solar cells possible. Sharp’s goal in the years to come is to take full advantage of this latest development success for use in concentrator-type solar cells, as well as for practical applications such as on space satellites and for flight craft and land vehicles.
Structure of Triple-Junction Compound Solar Cell
Wavelength Distribution of Solar Photo-Energy and Wavelength Sensitivity of Triple-Junction Compound Solar Cell