The US National Renewable Energy Laboratory (NREL) has verified a new ‘dual junction’ thin film solar cell technology from Alta Devices with a conversion efficiency of 30.8%.

Chris Norris, president and CEO of Alta Devices said: “Alta Devices has been setting efficiency records since 2010. This new dual junction record at 30.8% is a testament to our technology and our world-class team.  It’s also an important step toward our target of 38% efficient cells.”

Alta Devices said that its new dual junction technology used a second junction with Indium Gallium Phosphide (InGaP) as the absorber layer on top of the base single junction cell. 

InGaP is known to use high-energy photons more efficiently than a single junction Gallium Arsenide (GaAs) cell.  Alta Devices said that it was currently shipping its single junction Gallium Arsenide (GaAs) technology.