Congratulations to scientists at the National Renewable Energy Laboratory (NREL) who set two exciting new world records for efficiency with their six-junction solar cell. The cell had a solar conversion efficiency of 47.1% under concentrated illumination, while another version of the cell had an efficiency of 39.2%, a record for one-sun illumination.
The device is quite complex, with a film stack of approximately 140 III-V based layers. Amazingly, the total device thickness is still narrower than a human hair. The technical paper, “Six-junction III-V solar cells with 47.1% conversion efficiency under 143 Suns concentration” by John Geisz, Ryan France, Kevin Schulte, Myles Steiner, Andrew Norman, Harvey Guthrey, Matthew Young, Tao Son, and Thomas Moriarty was published in Nature Energy (April 2020, Vol 5) and gives further details on their accomplishment.
NREL uses multiple kSA MOS metrology instruments for thin-film stress measurement, multiple kSA 400 tools for RHEED analysis, and a kSA BandiT for thin-film temperature measurement in their research work.