Dmitry Baranov
Associate senior lecturer
Exploiting the Transformative Features of Metal Halides for the Synthesis of CsPbBr3@SiO2 Core-Shell Nanocrystals
Author
Summary, in English
The encapsulation of colloidal lead halide perovskite nanocrystals within silica (SiO2)
is one of the strategies to protect them from polar solvents and other
external factors. Here, we demonstrate the overcoating of CsPbBr3 perovskite nanocrystals with silica by exploiting the anhydride-induced transformation of Cs4PbBr6 nanocrystals. CsPbBr3@SiO2 core–shell nanocrystals are obtained after (i) a reaction between colloidal Cs4PbBr6 nanocrystals and maleic anhydride in toluene that yields CsPbBr3 nanocrystals and maleamic acid and (ii) a silica-shell growth around CsPbBr3 nanocrystals via hydrolysis of added alkoxysilanes. The reaction between Cs4PbBr6
nanocrystals and maleic anhydride is necessary to promote shell
formation from alkoxysilanes, as demonstrated in control experiments.
The best samples of as-prepared CsPbBr3@SiO2 nanocrystals consist of ∼10 nm single-crystal CsPbBr3
cores surrounded by ∼5–7 nm amorphous silica shell. Despite their
core–shell structure, such nanostructures are poor emitters and degrade
within minutes of exposure to ethanol. The photoluminescence intensity
of the core–shell nanocrystals is improved by the treatment with a
solution of PbBr2 and ligands, and their stability in ethanol
is extended to several days after applying an additional silica growth
step. Overall, the investigated approach outlines a strategy for making
colloidal core–shell nanocrystals utilizing the transformative chemistry
of metal halides and reveals interesting insights regarding the
conditions required for CsPbBr3@SiO2 nanocrystal formation.
is one of the strategies to protect them from polar solvents and other
external factors. Here, we demonstrate the overcoating of CsPbBr3 perovskite nanocrystals with silica by exploiting the anhydride-induced transformation of Cs4PbBr6 nanocrystals. CsPbBr3@SiO2 core–shell nanocrystals are obtained after (i) a reaction between colloidal Cs4PbBr6 nanocrystals and maleic anhydride in toluene that yields CsPbBr3 nanocrystals and maleamic acid and (ii) a silica-shell growth around CsPbBr3 nanocrystals via hydrolysis of added alkoxysilanes. The reaction between Cs4PbBr6
nanocrystals and maleic anhydride is necessary to promote shell
formation from alkoxysilanes, as demonstrated in control experiments.
The best samples of as-prepared CsPbBr3@SiO2 nanocrystals consist of ∼10 nm single-crystal CsPbBr3
cores surrounded by ∼5–7 nm amorphous silica shell. Despite their
core–shell structure, such nanostructures are poor emitters and degrade
within minutes of exposure to ethanol. The photoluminescence intensity
of the core–shell nanocrystals is improved by the treatment with a
solution of PbBr2 and ligands, and their stability in ethanol
is extended to several days after applying an additional silica growth
step. Overall, the investigated approach outlines a strategy for making
colloidal core–shell nanocrystals utilizing the transformative chemistry
of metal halides and reveals interesting insights regarding the
conditions required for CsPbBr3@SiO2 nanocrystal formation.
Publishing year
2022-01-11
Language
English
Pages
405-413
Publication/Series
Chemistry of Materials
Volume
34
Issue
1
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Status
Published
ISBN/ISSN/Other
- ISSN: 0897-4756