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Updated: Dec 17, 2025
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Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
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Photoinduced phase separation in the lead halides is a polaronic effect
David T Limmer1, Naomi S Ginsberg1
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
The Journal of Chemical Physics
|June 24, 2020
Summary
Photoinduced phase separation in lead-halide perovskites is reversible and composition-dependent. This phenomenon, driven by excess charge carriers, offers insights into material stability for optoelectronic applications.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Photophysics
Background:
- Multi-component lead-halide perovskites are crucial for optoelectronic devices.
- Understanding their phase stability under illumination is essential for device longevity.
- Photoinduced phase separation (PIPS) impacts material performance and durability.
Purpose of the Study:
- To provide a perspective on recent experimental observations of PIPS in lead-halide perovskites.
- To elucidate the mechanisms governing PIPS and its dependence on various factors.
- To review models explaining PIPS based on coupled physical phenomena.
Main Methods:
- Experimental observation of PIPS under steady-state illumination.
- Analysis of phase separation characteristics: reversibility, stochasticity, size limitations.
- Correlation of PIPS with material composition, thermodynamic state, and carrier concentration.
- Review of theoretical models involving charge carriers, composition, strain, and polarons.
Main Results:
- PIPS is a reversible, stochastic process, weakly dependent on morphology but strongly on composition and thermodynamic state.
- Phase-separated regions are self-limiting in size and grow with carrier concentration until saturation.
- Observations exclude defect-structure explanations, favoring modulation of miscibility transitions by excess charge carriers.
Conclusions:
- PIPS in lead-halide perovskites is governed by the interplay of composition, strain, and charge density fluctuations.
- The formation of polarons is a key mechanism linking these fluctuations.
- Understanding PIPS is critical for designing stable and efficient perovskite-based optoelectronic devices.
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