Abstract
The compositional engineering of lead-halide perovskite nanocrystals (NCs) via the A-site cation represents a lever to fine-tune their structural and electronic properties. However, the presently available chemical space remains minimal since, thus far, only three A-site cations have been reported to favor the formation of stable lead-halide perovskite NCs, i.e., Cs⁺ , formamidinium (FA), and methylammonium (MA). Inspired by recent reports on bulk single crystals with aziridinium (AZ) as the A-site cation, we present a facile colloidal synthesis of AZPbBr₃ NCs with narrow size distribution and size tunability down to 4 nm, producing quantum dots (QDs) in the regime of strong quantum confinement. NMR and Raman spectroscopies confirm the stabilization of the AZ cations in the locally distorted cubic structure. AZPbBr₃ QDs exhibit bright photoluminescence with quantum efficiencies of up to 80%. Stabilized with cationic and zwitterionic capping ligands, single AZPbBr₃ QDs exhibit stable single-photon emission – another essential attribute of QDs. In particular, didodecyldimethylammonium bromide and 2-octyldodecylphosphoethanolamine ligands afford AZPbBr₃ QDs with high spectral stability at both room and cryogenic temperatures, reduced blinking with a characteristic ON fraction larger than 85%, and high single-photon purity (g⁽²⁾ (0)=0.1), all comparable to the best-reported values for MAPbBr₃ and FAPbBr₃ QDs of the same size. Show more
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https://doi.org/10.3929/ethz-b-000650628Publication status
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Research SquarePublisher
Research SquareOrganisational unit
03934 - Kovalenko, Maksym / Kovalenko, Maksym
Funding
192308 - Q-Light - Engineered Quantum Light Sources with Nanocrystal Assemblies (SNF)
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Is previous version of: https://doi.org/10.3929/ethz-b-000665232
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