Photodriven Dipole Reordering: Key to Carrier Separation in Metalorganic Halide Perovskites

Hung Chang Hsu, Bo Chao Huang, Shu Cheng Chin, Cheng Rong Hsing, Duc Long Nguyen, Michael Schnedler, Raman Sankar, Rafal E. Dunin-Borkowski, Ching Ming Wei, Chun Wei Chen, Philipp Ebert*, Ya Ping Chiu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)


Photodriven dipole reordering of the intercalated organic molecules in halide perovskites has been suggested to be a critical degree of freedom, potentially affecting physical properties, device performance, and stability of hybrid perovskite-based optoelectronic devices. However, thus far a direct atomically resolved dipole mapping under device operation condition, that is, illumination, is lacking. Here, we map simultaneously the molecule dipole orientation pattern and the electrostatic potential with atomic resolution using photoexcited cross-sectional scanning tunneling microscopy and spectroscopy. Our experimental observations demonstrate that a photodriven molecule dipole reordering, initiated by a photoexcited separation of electron-hole pairs in spatially displaced orbitals, leads to a fundamental reshaping of the potential landscape in halide perovskites, creating separate one-dimensional transport channels for holes and electrons. We anticipate that analogous light-induced polarization order transitions occur in bulk and are at the origin of the extraordinary efficiencies of organometal halide perovskite-based solar cells as well as could reconcile apparently contradictory materials' properties.

Original languageEnglish
Pages (from-to)4402-4409
Number of pages8
JournalACS Nano
Issue number4
Publication statusPublished - 2019 Apr 23


  • electrostatic potential
  • light-induced polarization order transitions
  • one-dimensional carrier transport channels
  • organometal halide perovskites
  • photodriven dipole reordering
  • scanning tunneling microscopy/spectroscopy

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering
  • General Physics and Astronomy


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