Suppressed recombination for monolithic inorganic perovskite/silicon tandem solar cells with an approximate efficiency of 23%

Potentially temperature-resistant inorganic perovskite/silicon tandem solar cells (TSCs) are promising devices for boosting efficiency past the single-junction silicon limit. However, undesirable non-radiative recombination generally leads to a significant voltage deficit. Here, we introduce an effective strategy using nickel iodide, an inorganic halide salt, to passivate iodine vacancies and suppress non-radiative recombination. NiI2-treated CsPbI3-xBrx inorganic perovskite solar cells with a 1.80 eV bandgap exhibited an efficiency of 19.53% and a voltage of 1.36 V, corresponding to a voltage deficit of 0.44 V. Importantly, the treated device demonstrated excellent operational stability, maintaining 95.7% of its initial efficiency after maximum power point tracking for 300 h under continuous illumination in a N2 atmosphere. By combining this inorganic perovskite top cell with a narrower bandgap silicon bottom cell, we for the first time achieved monolithic inorganic perovskite/silicon TSCs, which exhibited an efficiency of 22.95% with an open-circuit voltage of 2.04 V. This work provides a promising strategy for using inorganic passivation materials to achieve efficient and stable solar cells.

Automated summary

This study introduces an effective strategy using an inorganic halide salt called nickel iodide to suppress non-radiative recombination in inorganic perovskite solar cells. By combining the inorganic perovskite top cell with a silicon bottom cell, the researchers achieved efficient and stable monolithic inorganic perovskite/silicon tandem solar cells for the first time. This work provides a promising strategy for using inorganic passivation materials to improve the performance and stability of solar cells.