Solliance partners TNO, imec/EnergyVille and the Eindhoven University of Technology, realized an 18.6% efficient highly near-infrared transparent perovskite solar cell. 

When combined in a four-terminal tandem configuration with an efficient Panasonic crystalline silicon (c-Si) cell or with a Miasolé flexible CIGS cell, delivers new record power conversion efficiencies of 28.7% and 27%, respectively.

Tandem technology offers a viable and attractive route to increase the efficiency of commercial solar cells and modules. 

Four terminal tandems allow building on experience and practices already available in the industry. 

Also, four-terminal perovskite/c-Si tandems can be applied broadly and are, for example, very beneficial in combination with bifacial c-Si solar cells which, depending on the actual albedo, can readily achieve a total power generation density as high as 320 W/m².

For this breakthrough, the expertise in perovskite solar cell processing and performance optimization of Solliance partners TNO, imec/EnergyVille and TU/e were combined to develop an efficient and highly near-infrared transparent perovskite solar cell with an efficiency of 18.6%.

This perovskite solar cell was combined with different architectures of bottom solar cells and even with different cell technologies, which demonstrates the wide applicability of the 4-terminal tandem approach:

• With a prototype c-Si Interdigitated Back Contact (IBC) Silicon Hetero Junction (SHJ) cell of Panasonic, a record tandem efficiency of 28.7% was obtained;
• With a commercial c-Si Metal Wrap Through (MWT) SHJ cell of Choshu Industry and Co, developed by TNO, a tandem efficiency of 28.2% was obtained;
• With a commercial c-Si Passivated Emitter and Rear Contact (PERC) cell of Solarlab Aiko Europe GmbH, a tandem efficiency of 27.7% was achieved;
• With a bandgap optimized flexible CIGS cell of MiaSolé, a record tandem efficiency of 27% was realized.

All of these results are more than 1.5% absolute efficiency improvements of earlier records obtained within the Solliance collaboration.