Abstract
We devised a colloidal approach for the synthesis of CsPbBr3 nanocrystals (NCs) in which the only ligands employed are alkyl phosphonic acids. Compared to more traditional syntheses of CsPbBr3 NCs, the present scheme delivers NCs with the following distinctive features: (i) The NCs do not have cubic but truncated octahedron shape enclosed by Pb-terminated facets. This is a consequence of the strong binding affinity of the phosphonate groups toward Pb2+ ions. (II) The NCs have near unity photoluminescence quantum yields (PLQYs), with no need of postsynthesis treatments, indicating that alkyl phosphonic acids are effectively preventing the formation of surface traps. (III) Unlike NCs coated with alkylammonium or carboxylate ligands, the PLQY of phosphonate coated NCs remains constant upon dilution, suggesting that the ligands are tightly bound to the surface.
| Original language | English |
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| Pages (from-to) | 9140-9147 |
| Number of pages | 8 |
| Journal | Chemistry of Materials |
| Volume | 31 |
| Issue number | 21 |
| DOIs | |
| Publication status | Published - 14 Oct 2019 |
Funding
We would like to thank M. Prato and G. Pugliese for carrying out the XPS and DLS measurements, respectively. We would like to thank also M. Imran for his help in the TEM analysis. We would like to thank Valerio Pinchetti of the Università degli Studi di Milano-Bicocca for measuring the PLQY of our NC systems. I.I. acknowledges The Netherlands Organization of Scientific Research (NWO) through the Innovational Research Incentive (Vidi) Scheme (Grant No. 723.013.002). The computational work was carried out on the Dutch national e-infrastructure with the support of the SURF Cooperative. We also acknowledge funding from the programme for research and Innovation Horizon 2020 (2014-2020) under the Marie Skłodowska-Curie Grant Agreement COMPASS No. 691185.