EneCoat Technologies Co., Ltd. recorded a conversion efficiency of 30.4% with a 4-terminal perovskite/silicon tandem solar cell, as part of a joint development project with Toyota Motor.

The company will now focus on modularization and enlargement of the cells. The perovskite solar cell, which has an IR transmittance improved to 81% and a conversion efficiency of 22.4%, while being a see-through type that allows light to pass through, was secured through the joint project. 

When installing solar cells on automobile roofs, they must conform to the vehicle’s curved surface. To address this, EneCoat and Toyota have developed a film-type see-through perovskite solar cell with an impressive 81% infrared (IR) transmittance and a conversion efficiency of 2.4%. To date, no other film-type perovskite solar cell in the world has achieved this level of efficiency along with such high IR transmittance. 

By combining this film-type perovskite solar cell with a crystalline silicon solar cell, EneCoat and Toyota successfully developed a 4-terminal tandem structure with world-class conversion efficiency of 30.4%. The newly developed 4-terminal tandem perovskite solar cell utilizes a two-layer structure to maximize performance. The upper perovskite solar cell captures visible light, while the lower silicon solar cell absorbs infrared light, generating more power through their combined output.

This accomplishment highlights the cutting-edge expertise of both companies. The reported efficiency was measured at the cell level within a limited area. Moving forward, the focus will be on modularization and enlargement of these cells, driving further development toward the practical implementation of high-efficiency solar technology with significant user benefits.

Since 2023, EneCoat has been working alongside Toyota to develop perovskite solar cells for automotive applications.