Fabrication of Efficient Formamidinium Tin Iodide Perovskite Solar Cells through SnF 2 –Pyrazine Complex

To fabricate efficient formamidinium tin iodide (FASnI3) perovskite solar cells (PSCs), it is essential to deposit uniform and dense perovskite layers and reduce Sn(4+) content. Here we used solvent-engineering and nonsolvent dripping process with SnF2 as an inhibitor of Sn(4+). However, excess SnF2 induces phase separation on the surface of the perovskite film. In this work, we report the homogeneous dispersion of SnF2 via the formation of the SnF2-pyrazine complex. Consequently, we fabricated FASnI3 PSCs with high reproducibility, achieving a high power conversion efficiency of 4.8%. Furthermore, the encapsulated device showed a stable performance for over 100 days, maintaining 98% of its initial efficiency.

• KR
  Korea Research Institute of Chemical Technology
• NR
  National Research Foundation of Korea

  Awards: NRF-2007-00091, NRF-2015M1A2A2056542, NRF-2011-0031565