Sharp Corporation has announced it has achieved the world’s highest non-concentrator solar cell conversion efficiency of 36.9% using a three-layered, triple-junction compound solar cell.
The company says the conversion efficiency was confirmed by the National Institute of Advanced Industrial Science and Technology in September this year.
Compound solar cells, primarily used on satellites, utilise light absorbing layers made from compounds consisting of two or more elements, such as indium and gallium.
Sharp has been pursuing the holy grail of maximum efficiency for this type of solar cell for over a decade. In 2009, it succeeded in improving cell conversion efficiency to 35.8% based on in-house technology that allowed for the efficient fabrication of a stacked triple-layer structure with InGaAs (indium gallium arsenide) as the bottom layer.
Their latest bump-up in conversion efficiency was attained by enhancing the maximum power output of the solar cell through reducing the resistance of the junction areas required to connect the solar cell layers in series.
Sharp aims to use this technology for incorporation in concentrator-type solar cells,satellites, aircraft and land vehicles. Sharp is no stranger to developing solar solutions for space applications – it began developing solar cells able to withstand the rigours of space in 1967, with the first satellite to use its solar cells being launched in 1976.
The Greenhouse gases Observing SATellite (GOSAT), “Ibuki”, which was launched in 2009 is equipped with Sharp triple-junction compound solar cells.
The company says processes yet to be developed for transferring ultra-thin photovoltaic layers onto film substrates will make lightweight, flexible solar cells of this nature possible.
Sharp’s efforts were supported by a research and development initiative promoted by Japan’s New Energy and Industrial Technology Development Organization (NEDO).
In addition to its ultra-high tech solar forays, Sharp solar panels are also a common sight on the rooftops of houses and commercial buildings around the world.
