Frauhover ISE achieves 35.9% performance for a monolithic tandem cell

• The Freiburg, Germany-based Fraunhofer Institute for Solar Energy Systems ISE has achieved a new performance globe record with a monolithic tandem cell made of III-V semiconductors (aspects from the third and 5th major teams of the table of elements) and silicon.

According to the institute, an efficiency of 35.9 percent was determined under an air mass of 1.5 (representing PV basic examination conditions). This is the same worth that research institutes NREL, CSEM as well as EPFL achieved back in 2017 with a III-V/Si tandem solar cell with 4 contacts; nonetheless, that cell had four calls. In contrast, in the ISE's cell design, "the III-V semiconductor layers are connected directly to the silicon sub-cell on the atomic degree. From the outdoors, the record cell looks like a two-terminal conventional solar cell." As necessary, an essential step for the improved performance was a brand-new compound semiconductor made of gallium indium arsenide phosphide (GaInAsP) between cell.

Due to the complicated structure and also the resulting manufacturing prices, III-V/Si tandem solar cells are, according to ISE quotes, for the time being only suitable for applications where a particularly great ratio of power to surface area as well as weight is very important, "for instance, in electrically powered airplane and drones". In the future, nonetheless, they will additionally be utilized for conventional modules.