Tandem Solar Cell Made of Perovskite and CIGS (Copper indium gallium selenide) Reaches Record Efficiency of 24.6 percent

The Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and the Nanoelectronics Research Center (Imec) from Belgium have developed a tandem thin-film solar cell with a record efficiency of 24.6 percent. 

Construction of a tandem module made of perovskite (top) and CIGS solar cells (bottom).

The tandem cell consists of a perovskite cell of Imec and a solar cell of the ZSW with a semiconductor of copper, indium, gallium and selenium (CIGS). The Perovski cell was created in partnership with the Belgian organizations EnergyVille and Solliance. 

Tandem solar cells consist of different, stacked solar cells. The concept electrifies many researchers: The layers use different areas of the sunlight spectrum better than the prevailing single solar cell. As a result, the multiple solar cells have a higher efficiency. Meanwhile, several variants of tandem cells are available. 

In the Belgian-German cooperation, a perovskite cell converts the light in the visible part of the solar spectrum into electricity, while the light in the near infrared spectrum, which penetrates the Perovskitzelle, is captured by a CIGS solar cell. Both cell types can be manufactured in thin-film technology and are particularly suitable for flexible high-efficiency solar cells and building-integrated photovoltaic solutions.