Sol Voltaics AB of Lund, Sweden, which provides nanomaterial technology for enhancing solar panels and other products, has demonstrated a 1-sun photovoltaic (PV) solar energy conversion efficiency of 15.3% using a gallium arsenide (GaAs) nanowire array (NWA), as independently verified by Germany's Fraunhofer ISE (Institute for Solar Energy Systems).
This exceeds the existing efficiency record for a III-V NWA solar cell - of 13.8%, set in 2013 by Lund University, using indium phosphide (InP) NWA technology - and specifically doubles the record for GaAs NWA technology (7.58%, set in 2014).
Sol Voltaics says that control of the high density of surface states of native GaAs is essential for PV applications, and that the new results prove that it has resolved this challenge in the growth of solar cell nanowires.
"The efficiency of our GaAs nanowires is a critical component of our low-cost film," says CEO Erik Smith. "The use of III-V materials in the PV industry has always been a goal, but the costs have been prohibitive," he adds. "Using Sol Voltaic's Aerotaxy nanowire production methodology allows our III-V film to be produced at competitive cost at efficiencies that are industry changing."
Sol Voltaics reckons that its GaAs NWA solar cell represents a significant step towards an efficiency-boosting tandem film. "We look forward to working with industrial partners on the integration of our technology on to silicon cells so they may make the leap to 27% efficiency and beyond," says Smith.
