Related Experiment Videos
Highly Emissive Green Perovskite Nanocrystals in a Solid State Crystalline Matrix
Li Na Quan1, Rafael Quintero-Bermudez1, Oleksandr Voznyy1
1Department of Electrical and Computer Engineering, University of Toronto, 35 St George Street, Toronto, Ontario, M5S 1A4, Canada.
Advanced Materials (Deerfield Beach, Fla.)
|April 4, 2017
Summary
Researchers developed a method to create highly efficient green-emitting perovskite nanocrystals (NCs) in a solid state. Embedding these NCs in a stable matrix achieved a 90% photoluminescence quantum yield (PLQY).
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Physics
Background:
- Perovskite nanocrystals (NCs) exhibit high photoluminescence quantum yield (PLQY) in solution.
- Maintaining high emission efficiency of NCs in the solid state is a significant challenge.
- Agglomeration and surface defects in solid-state NCs often lead to reduced PLQY.
Purpose of the Study:
- To develop a solution-phase synthesis for efficient solid-state green-emitting perovskite NCs.
- To embed perovskite NCs within a robust and air-stable matrix to enhance their optical properties.
- To investigate the mechanisms responsible for improved PLQY in the embedded NCs.
Main Methods:
- Solution-phase synthesis of cesium lead bromide (CsPbBr3) perovskite NCs.
- Embedding CsPbBr3 NCs within a rhombic prism hexabromide (Cs4PbBr6) microcrystal matrix.
- Photoluminescence quantum yield (PLQY) measurements.
- Theoretical modeling and experimental characterization (e.g., lattice matching, spatial confinement analysis).
Main Results:
- Achieved a high PLQY of 90% for green-emitting perovskite NCs in the solid state.
- Successfully embedded CsPbBr3 NCs in a stable Cs4PbBr6 matrix.
- Demonstrated that lattice matching between NCs and the matrix improves passivation.
- Observed that spatial confinement enhances the radiative rate of the NCs.
- Prevented NC agglomeration by dispersing them within the matrix, contributing to high PLQY.
Conclusions:
- The developed method enables the creation of highly efficient solid-state perovskite light emitters.
- Lattice matching and spatial confinement are key factors for achieving high PLQY in embedded NCs.
- Embedding perovskite NCs in a stable matrix is an effective strategy to overcome solid-state quenching and agglomeration issues.