Cs4PbBr6 (0D) nanocrystals at room temperature have both been reported as nonemissive and green-emissive systems in conflicting reports, with no consensus regarding both the origin of the green emission and the emission quenching mechanism. Here, via ab initio molecular dynamics (AIMD) simulations and temperature-dependent photoluminescence (PL) spectroscopy, we show that the PL in these 0D metal halides is thermally quenched well below 300 K via strong electron-phonon coupling. To unravel the source of green emission reported for bulk 0D systems, we further study two previously suggested candidate green emitters: (i) a Br vacancy, which we demonstrate to present a strong thermal emission quenching at room temperature; (ii) an impurity, based on octahedral connectivity, that succeeds in suppressing nonradiative quenching via a reduced electron-phonon coupling in the corner-shared lead bromide octahedral network. These findings contribute to unveiling the mechanism behind the temperature-dependent PL in lead halide materials of different dimensionality.
|Number of pages||8|
|Early online date||13 Oct 2021|
|Publication status||Published - 27 Oct 2021|
Bibliographical noteFunding Information:
I.I. acknowledges The Netherlands Organization of Scientific Research (NWO) for financial support through the Innovational Research Incentive (Vidi) Scheme (723.013.002), and S.C.B. acknowledges financial support through the Innovational Research Incentives (Veni) Scheme (722.017.011). R.K. received funding from the European Union under the Marie Skłodowska-Curie RISE project COMPASS no. 691185 and from the AI-4-QD project financed by the Italian Ministry of Foreign affairs and International Cooperation (MAECI) within the bilateral Italy–Israel program. The computational work was carried out on the Dutch national e-infrastructure with the support of the SURF Cooperative.
© 2021 The Authors. Published by American Chemical Society.
- Density Functional Theory
- Green Emission
- Molecular Dynamics
- Nonradiative Quenching