Imec Perovskite/Silicon Tandem Photovoltaic Module Achieves 23.9% Conversion Efficiency

Imec perovskite tandem photovoltaic module

Imec, the research and innovation hub in Leuven, Belgium, which is also a partner in Solliance and EnergyVille, announced an improvement of its 4cm2 perovskite/silicon tandem photovoltaic module. The perovskite/silicon tandem photovoltaic module achieved a power conversion efficiency of 23.9 percent. At this level, imec says that its researchers are the first to develop a module-on-cell stack that outperforms a stand-alone silicon solar cell.

In 2016, imec presented a semi-transparent perovskite module, that its researchers developed in collaboration with Solliance.
The semi-transparent perovskite module was stacked on an interdigitated back-contact (IBC) crystalline silicon solar cell in a four-terminal tandem configuration.

At the time, the tandem module achieved a power conversion efficiency of 20.2 percent on an aperture area of 4cm2. In a significant improvement to the technology, Imec now reports that for the module-on-cell stack with the same size, it achieved a record high power conversion efficiency of 23.9 percent.

“Two innovations are key to this achievement,” explained Tom Aernouts, group leader for thin-film photovoltaics at imec and perovskite PV program manager at Solliance. “First, a different perovskite material (CsFAPbIBr) was used, largely improving the stability and conversion efficiency of the 4cm² semi-transparent perovskite module to 15.3 percent. Second, the architecture of the stack was optimized for minimal optical losses by adding an anti-reflection texture on top of the module and a refractive index matching liquid between the perovskite module and the Si solar cell.”

“Having matched areas of this size makes the fabrication technology more attractive to the solar cell industry,” commented Aernouts.