Fraunhofer ISE claims 47.6% solar cell efficiency record

• Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) have laid claim to a new solar cell efficiency record of 47.6%.

Researchers said the efficiency for a four-junction cell had been enhanced from 46.1% to 47.6% at a concentration of 665 sunlight, thanks to improvements in a four-layer antireflection coating related to the tandem cell structure. This decreased resistance losses and also the reflection on the front side of the cell.

The layer structure of this solar cell was developed back in 2016 together with French semiconductor manufacturer Soitec, with the top tandem solar cell made of gallium indium phosphide (GaInP) and aluminium gallium arsenide (AlGaAs), affixed to a lower tandem solar cell made of gallium indium arsenide phosphide (GaInAsP) as well as gallium indium arsenide (GaInAs).

Conventional solar cells constructed from silicon can only take in sunshine up to a wavelength of 1200 nanometres but Fraunhofer ISE's record-breaking solar cell managed to expand the wide array up to 1780 nanometres.

The attribute comes only 2 years after Fraunhofer began the "half" project, which intends to develop a solar cell with a 50% efficiency, as well as only one year after it opened its new Center for High Efficiency Solar Cells, stated Frank Dimroth, department head of III-V Photovoltaics and Concentrator Technology at Fraunhofer ISE.

"In our research, we aim to make concentrating photovoltaics even more effective and affordable, as we believe that this is one of the most lasting type of renewable electricity generation," added Dimroth.