Boosted device performance of perovskite solar cells via KI processing additives

Perovskite solar cells (PSCs) have attracted great attention in both academic and industrial sectors in the past years. Studies demonstrated that processing additive engineering was a facile way to improve the crystallinity and minimize the defect of metal halide perovskites (MHPs). In this study, we report efficient and stable PSCs, where the MHPs thin film is processed with KI additives. It is found that the KI processing additives could not only enhance the crystallization and suppress the defects of MHP thin film, but also boost charge transport, suppress non-radiative recombination, and enhance the hydrophobic properties of MHP thin film. As a result, the PSCs based on the MHPs thin film processed with KI additives exhibit more than 10% enhancement in efficiency and dramatically boosted stability compared to that based on pristine MHPs thin film. Our results indicated that the MHPs processed with processing additives are a simple engineering technique to boost the device performance of PSCs.