Imec combines different solar cells to target efficiencies above 30%

Nanoelectronics research centre imec of Leuven, Belgium has unveiled its new tandem solar cell technologies, paving the way to higher cell efficiencies of photovoltaic (PV) panels on roofs as well as on vehicles or building-integrated photovoltaic (BIPV) applications such as solar cells in windows or facades. Tandem cells combine two types of solar cells applied on top of each other. Because each cell uses a different part of the sunlight spectrum, very high efficiencies beyond 30% can be achieved.

In its tandem cells, imec combines copper indium gallium selenide (CIGS) or silicon solar cells with perovskite, a material that enables thin, transparent and cheap solar cells. As perovskite solar cells utilize the visible part of the light spectrum, they are suitable for combining with CIGS or silicon solar cells, which utilize more the near-IR light portion of the spectrum instead. Tandem cells are therefore able to convert sunlight more efficiently.

Imec’s perovskite/silicon cell combines its 0.13cm2 perovskite cell, developed within the Solliance collaboration, with a 4cm2 silicon solar cell. The tandem cell achieves a conversion efficiency of 27.1%, which is higher than the best silicon solar cell (26.6%). Imec’s perovskite/CIGS cell combines the 0.13cm2 perovskite cell with a 3.8cm2 CIGS module developed by ZSW (Zentrum für Sonnenenergie- und Wasserstoff-Forschung — or Center for Solar Energy and Hydrogen Research — Baden-Württemberg) in Stuttgart, Germany. This tandem cell achieves 24.6% efficiency, which is also higher than the leading CIGS solar cells (22.9%).

“According to the International Technology Roadmap for PV (ITRPV), tandem solar cells are expected to appear in the market in 2021,” says Tom Aernouts, group leader thin-film PV at imec/Energyville. “At imec, we work on perovskite/silicon as well as on perovskite/CIGS tandems because each technology is directed towards different applications,” he adds. “For instance, silicon solar cells are especially suited for roofs and in solar cell parks, while CIGS thin-film solar cells can be produced on foils that could, in the future, be applied for building-integrated PV, turning facades and windows into electricity producers.”

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Imec’s perovskite-silicon tandem cell efficiency of 27.1% beats standalone silicon solar cell

Tags: ZSW CIGS

Visit: www.zsw-bw.de

Visit: www.imec.be

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