Critical Role of Methylammonium Librational Motion in Methylammonium Lead Iodide (CH3NH3PbI3) Perovskite Photochemistry

Myeongkee Park, Nikolay Kornienko, Sebastian E. Reyes-Lillo, Minliang Lai, Jeffrey B. Neaton, Peidong Yang, Richard A. Mathies

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


Raman and photoluminescence (PL) spectroscopy are used to investigate dynamic structure-function relationships in methylammonium lead iodide (MAPbI3) perovskite. The intensity of the 150 cm-1 methylammonium (MA) librational Raman mode is found to be correlated with PL intensities in microstructures of MAPbI3. Because of the strong hydrogen bond between hydrogens in MA and iodine in the PbI6 perovskite octahedra, the Raman activity of MA is very sensitive to structural distortions of the inorganic framework. The structural distortions directly influence PL intensities, which in turn have been correlated with microstructure quality. Our measurements, supported with first-principles calculations, indicate how excited-state MA librational displacements mechanistically control PL efficiency and lifetime in MAPbI3 - material parameters that are likely important for efficient photovoltaic devices.

Original languageEnglish
Pages (from-to)4151-4157
Number of pages7
JournalNano Letters
Issue number7
Publication statusPublished - 12 Jul 2017


  • DFT
  • MAPbI
  • Methylammonium lead iodide perovskite
  • photoluminescence microscopy
  • photovoltaics
  • Raman microscopy

ASJC Scopus subject areas

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


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