EU PVSEC Programme Online
EU PVSEC 2021, 6 - 10 September 2021
Presentation: 3AO.5.3 Process and Layer Optimization for the Fabrication of Highly Efficient Perovskite/ACIGS Thin-Film Tandem Solar Cells
Type: Oral
Date: Monday, 6th September 2021
15:15 - 16:45
Author(s): S. Essig, T. Wahl, S. Paetel, D. Hariskos, T. Magorian-Friedlmeier, M. Loy, J. Hanisch, E. Ahlswede, M. Powalla
Presenter / Speaker: S. Paetel, ZSW, Stuttgart, Germany
Event: Conference Conference
Session: 3AO.5 Tandem Solar Cells Process and Performance
Topic: 3. 5 Tandems
Summary / Abstract: Tandem cells with perovskite top cells and (Ag,Cu)(In,Ga)Se2 bottom cells (ACIGS) offer a promising strategy towards realizing all thin-film dual-junction devices with efficiencies exceeding 30%. While perovskites are an emerging and fast progressing technology, bottom cells based on chalcopyrites are a more mature technology, offer an adjustable bandgap energy and are known for their low energy payback time. In our studies we have investigated the deposition of Ag-alloyed Cu(In,Ga)Se2 absorber layers and optimized their properties for application in tandem solar cells with solution-processed perovskite top cells. The incorporation of Ag in the chalcopyrite absorber layer enables a smooth surface, which is found to be advantageous for spin-coating of subsequent top cell layers. Since currentmatching between the subcells is essential in 2-terminal tandems, we have developed narrow-bandgap ACIGS bottom cells with lower Ga-content and thus enhanced long-wavelength absorption. To further boost their red response, the integration of intermediate hole-selective metal oxide layers has been tested and cell properties were further analyzed by SEM, EDX and GDOES measurements. In our presentation, we will discuss our optimization of ACIGS bottom cells and present results of perovskite/ACIGS tandem solar cells, which have achieved efficiencies of 17.7% in initial experiments.