Self-Passivation of 2D Ruddlesden-Popper Perovskite by Polytypic Surface PbI2 Encapsulation

Hee Joon Jung, Constantinos C. Stompus, Mercouri G. Kanatzidis, Vinayak P. Dravid*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Two-dimensional Ruddlesden-Popper (2D RP) halide perovskites, C2MAn-1PbnI3n+1 (C = bulky ammonium cation; MA = methylammonium) with low n-members (n < 5), have been garnering sensational attention for photovoltaic and optoelectronic applications because of the long carrier diffusion lengths, long-term stability, and tunable bandgap. Yet, the surface modification of 2D RP under kinetic particle irradiation, such as light or electron irradiation, is ambiguous, even though it is imperative to elucidate long-stabilized conversion efficiency. Herein, we present molecular-scale observations of dynamic surface reconstruction of BA2MA2Pb3I10 (n = 3) 2D RP induced by the electron beam. The surface dynamics reveal lateral growth of polytypic PbI2 with 3R, 4H, and 2H structures at the edge and surface of the 2D perovskite, accompanied by simultaneous annihilation at the other edges. Local radiolysis occurs dominantly by the internal energy increase of electron momentum transfer, which triggers a sequential layer-by-layer degradation into PbI2. In situ observation of the polytypic PbI2 growth at the whole surface and edges of 2D RP under electron irradiation elucidates how the outer PbI2 self-passivation can protect inner 2D RP, causing longer operando stability.

Original languageEnglish (US)
Pages (from-to)6109-6117
Number of pages9
JournalNano letters
Issue number9
StatePublished - Sep 11 2019


  • 2D Ruddlesden-Popper halide perovskite
  • BAMAPbI 2D halide perovskite
  • electron beam irradiation
  • in situ TEM
  • long-term stability
  • polytypic PbI surface self-passivation

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering


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