Abstract
Postsynthetic chemical transformations of colloidal nanocrystals, such as ion-exchange reactions, provide an avenue to compositional fine-tuning or to otherwise inaccessible materials and morphologies. While cation-exchange is facile and commonplace, anion-exchange reactions have not received substantial deployment. Here we report fast, low-temperature, deliberately partial, or complete anionexchange in highly luminescent semiconductor nanocrystals of cesium lead halide perovskites (CsPbX3, X = Cl, Br, I). By adjusting the halide ratios in the colloidal nanocrystal solution, the bright photoluminescence can be tuned over the entire visible spectral region (410-700 nm) while maintaining high quantum yields of 20 80% and narrow emission line widths of 10-40 nm (from blue to red). Furthermore, fast internanocrystal anion-exchange is demonstrated, leading to uniform CsPb(Cl/Br)(3) or CsPb(Br/I)(3) compositions simply by mixing CsPbCl3, CsPbBr3, and CsPbI3 nano crystals in appropriate ratios.
Original language | English |
---|---|
Pages (from-to) | 5635-5640 |
Number of pages | 6 |
Journal | Nano Letters |
Volume | 15 |
Issue number | 8 |
DOIs | |
Publication status | Published - 12-Aug-2015 |
Externally published | Yes |
Keywords
- Nanocrystals
- perovskites
- metal halides
- cation exchange
- anion exchange
- photoluminescence
- CATION-EXCHANGE
- GALVANIC REPLACEMENT
- HOLLOW NANOCRYSTALS
- QUANTUM DOTS
- NANOSCALE
- PHASE
- LIGHT
- NANOSTRUCTURES
- BRIGHT