Structural and Chemical Changes to CH3NH3PbI3 Induced by Electron and Gallium Ion Beams

Mathias Uller Rothmann, Wei Li, Ye Zhu, Amelia Liu, Zhiliang Ku, Udo Bach, Joanne Etheridge, Yi Bing Cheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

49 Citations (Scopus)

Abstract

Organic–inorganic hybrid perovskites, such as CH3NH3PbI3, have shown highly promising photovoltaic performance. Electron microscopy (EM) is a powerful tool for studying the crystallography, morphology, interfaces, lattice defects, composition, and charge carrier collection and recombination properties at the nanoscale. Here, the sensitivity of CH3NH3PbI3 to electron beam irradiation is examined. CH3NH3PbI3 undergoes continuous structural and compositional changes with increasing electron dose, with the total dose, rather than dose rate, being the key operative parameter. Importantly, the first structural change is subtle and easily missed and occurs after an electron dose significantly smaller than that typically applied in conventional EM techniques. The electron dose conditions under which these structural changes occur are identified. With appropriate dose-minimization techniques, electron diffraction patterns can be obtained from pristine material consistent with the tetragonal CH3NH3PbI3 phases determined by X-ray diffraction. Radiation damage incurred at liquid nitrogen temperatures and using Ga+ irradiation in a focused ion beam instrument are also examined. Finally, some simple guidelines for how to minimize electron-beam-induced artifacts when using EM to study hybrid perovskite materials are provided.

Original languageEnglish
Article number1800629
JournalAdvanced Materials
Volume30
Issue number25
DOIs
Publication statusPublished - 20 Jun 2018

Keywords

  • CHNHPbI
  • composition
  • focused ion beam
  • structure
  • transmission electron microscope

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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