posted on 2023-10-26, 21:30authored byChunqing Ma, Min-Chul Kang, Sun-Ho Lee, Yalan Zhang, Dong-Ho Kang, Wenxin Yang, Pin Zhao, Sang-Woo Kim, Seok Joon Kwon, Cheol-Woong Yang, Yang Yang, Nam-Gyu Park
Understanding
the interplay between the surface structure
and the
passivation materials and their effects associated with surface structure
modification is of fundamental importance; however, it remains an
unsolved problem in the perovskite passivation field. Here, we report
a surface passivation principle for efficient perovskite solar cells
via a facet-dependent passivation phenomenon. The passivation process
selectively occurs on facets, which is observed with various post-treatment
materials with different functionality, and the atomic arrangements
of the facets determine the alignments of the passivation layers.
The profound understanding of facet-dependent passivation leads to
the finding of 2-amidinopyridine hydroiodide as the material for a
uniform and effective passivation on both (100) and (111) facets.
Consequently, we achieved perovskite solar cells with an efficiency
of 25.10% and enhanced stability. The concept of facet-dependent passivation
can provide an important clue on unidentified passivation principles
for perovskite materials and a novel means to enhance the performance
and stability of perovskite-based devices.