Inorganic ammonium salt doping in nickel oxide for highly efficient planar perovskite solar cells

The article discusses the challenges and limitations of using nickel oxide (NiOx) as a hole transport material in perovskite solar cells, particularly focusing on the issues of low conductivity and impurity-induced interface redox reactions. It introduces a novel method of using ammonium salts to synthesize NiOx nanoparticles, which significantly improves the Ni3+/Ni2+ ratio and reduces impurities. This innovative approach enhances the charge conductivity and stabilizes the perovskite film/NiOx interface, leading to improved solar cell efficiency. The study also incorporates various characterization techniques to validate the enhanced performance, including X-ray diffraction, electron paramagnetic resonance, and ultraviolet-visible spectroscopy. The results demonstrate that ammonium salt doping, particularly with NH4SCN, can achieve remarkable improvements in solar cell efficiency, reaching up to 23% with the addition of a MeO-2PACz monolayer. The article concludes by emphasizing the potential of ammonium salt doping in optimizing the performance of perovskite solar cells, offering valuable insights for further research in this field.