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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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White-Light Emission from Layered Halide Perovskites.
Matthew D Smith1, Hemamala I Karunadasa1
1Department of Chemistry , Stanford University , Stanford , California 94305 , United States.
Accounts of Chemical Research
|February 21, 2018
Summary
Researchers discovered that layered perovskites can emit broadband white light through exciton self-trapping, a promising development for energy-efficient solid-state lighting. This mechanism offers a single-material solution to overcome challenges in current white-light technologies.
Area of Science:
- Materials Science
- Solid-State Physics
- Photochemistry
Background:
- Global electricity consumption by lighting necessitates energy-efficient illumination sources.
- Current white-light technologies often rely on multiple components, leading to degradation and efficiency losses.
- A single material capable of broadband white-light emission is highly desirable.
Purpose of the Study:
- To understand the mechanism behind broadband white-light emission from layered perovskites.
- To explore the potential of these materials as efficient and stable white-light emitters.
- To identify structural parameters that can be tuned for optimal white-light emission.
Main Methods:
- Investigated layered hybrid halide perovskites, specifically focusing on lead-halide compositions.
- Employed ultrafast spectroscopic measurements to probe photoexcitation and emission dynamics.
- Correlated structural properties, such as octahedral tilting, with emission characteristics.
Main Results:
- Observed broadband white-light emission (400-700 nm) from layered perovskites upon near-UV excitation.
- Attributed the broad emission primarily to exciton self-trapping, forming transient, lattice-stabilized excited states.
- Demonstrated that increased out-of-plane octahedral tilting enhances broadband emission propensity.
Conclusions:
- Layered perovskites offer a promising single-material approach for generating high-quality white light.
- The exciton self-trapping mechanism provides a pathway for designing stable and efficient white-light emitters.
- These materials exhibit excellent color rendering and potential for cost-effective, large-area deposition in solid-state lighting applications.
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