Abstract
Colloidal lead halide perovskite nanocrystals (NCs) have recently emerged as versatile photonic sources. Their processing and luminescent properties are challenged by the lability of their surfaces, i.e., the interface of the NC core and the ligand shell. On the example of CsPbBr3 NCs, we model the nanocrystal surface structure and its effect on the emergence of trap states using density functional theory. We rationalize the typical observation of a degraded luminescence upon aging or the luminescence recovery upon postsynthesis surface treatments. The conclusions are corroborated by the elemental analysis. We then propose a strategy for healing the surface trap states and for improving the colloidal stability by the combined treatment with didodecyldimethylammonium bromide and lead bromide and validate this approach experimentally. This simple procedure results in robust colloids, which are highly pure and exhibit high photoluminescence quantum yields of up to 95-98%, retained even after three to four rounds of washing.
| Original language | English |
|---|---|
| Pages (from-to) | 63-74 |
| Number of pages | 12 |
| Journal | ACS Energy Letters |
| Volume | 4 |
| Issue number | 1 |
| Early online date | 27 Nov 2018 |
| DOIs | |
| Publication status | Published - 11 Jan 2019 |
Funding
This work was financially supported by the European Union through the FP7 (ERC Starting Grant NANOSOLID, GA No. 306733), by the Swiss Federal Commission for Technology and Innovation (CTI-No. 18614.1 PFNM-NM). M.I.B. acknowledges financial support from the Swiss National Foundation (SNF Ambizione Energy Grant No. PZENP2_154287). I.I. acknowledges The Netherlands Organization of Scientific Research (NWO) for financial support through the Innovational Research Incentive (Vidi) Scheme (Grant No. 723.013.002) and S.C.B. for financial support through the Innovational Research Incentives (Veni) Scheme (Grant No. 722.017.011). The computational work was carried out on the Dutch national e-infrastructure with the support of the SURF Cooperative. The authors are grateful to Empa Electron Microscopy Center for access to the instruments and for technical assistance.
| Funders | Funder number |
|---|---|
| Innovational Research Incentives | 722.017.011 |
| Netherlands Organization of Scientific Research | |
| Swiss Federal Commission for Technology and Innovation | 18614.1 PFNM-NM |
| Swiss National Foundation | |
| Seventh Framework Programme | 306733 |
| European Commission | |
| European Research Council | |
| Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | PZENP2_154287 |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 723.013.002 |
| Seventh Framework Programme |
