Enhancing Dielectric Screening for Auger Suppression in CdSe/CdS Quantum Dots by Epitaxial Growth of ZnS Shell.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33938759.
- Also identified by DOI 10.1021/acs.nanolett.1c00396.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Auger recombination is the main nonradiative process in multicarrier states of high-quality quantum dots (QDs). For the most-studied CdSe/CdS core/shell QDs, we effectively reduce the biexciton Auger rate by enhancing dielectric screening of band-edge carriers via epitaxial growth of additional ZnS shells. Super volume scaling of negative-trion Auger lifetime for CdSe/CdS core/shell QDs is achieved with the outermost ZnS shells. The volume of CdSe/CdS/ZnS QDs can be less than half that of CdSe/CdS QDs with the same negative-trion Auger lifetime. Auger suppression by the ZnS shells is more pronounced for QDs with wave functions of band-edge carriers spreading close to the inorganic-organic interface, such as CdSe/CdS QDs with small cores. A maximum drop of biexciton Auger rate of ∼50% and a maximum enhancement of biexciton emission quantum yield of 75% are achieved. Auger engineering by dielectric screening opens up new opportunities to improve the emission properties of multicarrier states in QDs.