North Carolina-based Semprius Inc. has manufactured a four-junction, four-terminal stacked solar cell using its micro-transfer printing process.
The new solar cell consists of a three-junction microcell that is stacked on top of a single-junction germanium microcell. Semprius worked with the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign and Solar Junction on the effort.
Semprius says that by using four junctions, the stacked cell is able to capture light across a broader portion of the spectrum and therefore achieve higher efficiencies. According to the company, initial trials yielded solar cells with measured efficiencies up to 43.9%.