Monolithic perovskite/silicon tandem solar cells – which silicon surface texture is the best choice?

Bernd Stannowski, Angelika Harter, Jona Kurpiers, Tobias Bertram, Steffi Severin, Philipp Wagner, Lars Korte, Christiane Becker, Rutger Schlatmann, Steve Albrecht

Helmholtz-Zentrum Berlin, Solar Energy Division, Germany

E-mail: bernd.stannowski@helmholtz-berlin.de

Abstract

Monolithic perovskite/silicon tandem solar cells are promising candidates for next generation solar cells surpassing the power conversion efficiency (PCE) limit of silicon and enabling PV modules to cross PCEs of 30% at competitive costs. In recent years we achieved several PCE world records at HZB with tandem cells reaching 32.5% on lab size in 2023. However, various challenges will need to be overcome before a mature technology basis is available for commercialization. Upscaling the perovskite processing on top of the silicon is one key research topic. It was still done by spin coating on a polished Si surface for above lab cells, which is not a viable path for industrialization. At HZB various alternative deposition methods are investigated, with a focus on vacuum-based evaporation, but also solution-based and hybrid methods are investigated. Here, we will introduce this technology and show results obtained with these techniques on various silicon topographies, from large via sub-micron random pyramids to nano-textures.

Biography:

Bernd Stannowski is a principal investigator at Helmholtz-Zentrum Berlin (HZB) and a full professor at the University of Applied Sciences, Berliner Hochschule für Technik (BHT). His background is in thin-film silicon technology with eight years of experience in thin-film PV industry. His present research topics are silicon-heterojunction solar cells and monolithic perovskite/silicon tandem solar cells. In his work he focusses on industrial compatible process and upscaling. Bernd Stannowski is (co)author of >120 paper and holds several patents.