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Updated: Mar 1, 2026
08:30
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
17.2K
Tetragonal CH3NH3PbI3 is ferroelectric
Yevgeny Rakita1, Omri Bar-Elli2, Elena Meirzadeh1
1Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 7610001, Israel.
Summary
Methylammonium lead triiodide (MAPbI3) is pyroelectric and ferroelectric, confirmed by hysteresis loops and polar domains. This finding offers insights into its potential role in high-performance solar cells.
Area of Science:
- Materials Science
- Solid State Physics
- Photovoltaics
Background:
- Halide perovskites (HaPs) show remarkable solar cell performance, attributed partly to low carrier recombination.
- The potential ferroelectric nature of methylammonium lead triiodide (MAPbI3) was hypothesized to explain carrier separation and low recombination.
- Experimental evidence for MAPbI3's ferroelectricity was lacking due to its electrical properties and stability issues.
Purpose of the Study:
- To provide experimental evidence for the ferroelectric properties of methylammonium lead triiodide (MAPbI3).
- To investigate the ferroelectric hysteresis and domain structure in MAPbI3 single crystals.
- To explore the noncentrosymmetric nature of MAPbI3 through second harmonic generation.
Main Methods:
- Operando pyroelectric measurements to establish potential ferroelectricity.
- Ferroelectric hysteresis loop measurements on single crystals at low temperatures, adapted for leaky materials.
- Chemical etching to visualize polar domains and their structural characteristics.
- Second harmonic generation (SHG) measurements to confirm noncentrosymmetry.
Main Results:
- Methylammonium lead triiodide (MAPbI3) was confirmed to be pyroelectric, a precursor to ferroelectricity.
- Ferroelectric hysteresis loops were observed in MAPbI3 single crystals, demonstrating switchable polarization.
- Polar domains, characteristic of ferroelectricity, were visualized and found to scale with crystal size.
- Second harmonic generation confirmed the noncentrosymmetric crystal structure of MAPbI3.
Conclusions:
- MAPbI3 exhibits ferroelectric properties, evidenced by hysteresis, polar domains, and noncentrosymmetry.
- The ferroelectric nature of MAPbI3, while not essential, could contribute to the performance of photovoltaic devices.
- These findings advance the understanding of halide perovskites for solar energy applications.
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