Science News: 2021 ACS Energy Lett. Achieve over 33% PCE Advanced Perovskite/Silicon Tandem Solar Cell through Thorough Subcell Diagnosis Methodology
ACS Energy Letters (IF 19.05) published the research by Martin Stolterfoht from University of Potsdam in Germany and Steve Albrecht et al. in September 2021. As perovskite/silicon tandem photovoltaics (PVs) are expected to accelerate the decarbonization of our energy systems, the authors of this study propose a thorough subcell diagnosis methodology to gain insight into the practical efficiency limitations of state-of-the-art perovskite/silicon tandem photovoltaics.
Sub-cell selective intensity-dependent photoluminescence (PL) and injection-related electroluminescence (EL) can measure the pseudo-VOC and power conversion efficiencies (PCEs) for both sub-cells. The article shows that identical metrics from PL and EL represent that well-aligned energy levels throughout the entire cell. However, a relatively large ideality factors and insufficient charge extraction will result in a loss of approximately 6% (absolute) for each fill factor penalty. In addition, if partial device stacks are used, the standard perovskite subcells will cause significant losses due to bulk and interfacial recombination. Through experiments using solar simulators and other instruments, finally proposed the use of triple halide (CsFAPb(IBrCl)3) based perovskites to minimize these losses. Utilizing the results can be more helpful for future device development and lay the foundation for advanced perovskite/silicon tandem PVs that can exceed 33% PCE.
Current-voltage characteristics of a triple halide perovskite-based single junction solar cell in comparison to a standard double-halide (or triple cation) perovskite.
Silicon single junction JV characteristics. Black: under non-filtered AM1.5G illumination. Red: under filtered AM1.5G illumination comparable to the silicon bottom subcell in a perovskite/silicon tandem stack.