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PbS/CdS Core/Shell quantum dots by additive, layer-by-layer shell growth

(2016) CHEMISTRY OF MATERIALS. 28(19). p.6953-6959
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Abstract
We demonstrate additive shelling of PbS core quantum dots by CdS using room-temperature colloidal atomic layer deposition. Combining in-depth electron microscopy, absorption spectroscopy and elemental analysis, we present a structural model of the PbS/CdS core/shell quantum dots after each of the successive colloidal ALD cycles. In particular, we find that such core/shell quantum dots are cation-rich and we argue that this nonstoichiometry should be attributed to a Cd-excess at the outer surface. Analyzing various PbS/CdS core/shell QDs, we demonstrate that CdS shells have no effect on the energy of the PbS band-edge transition for PbS core QDs larger than ≈4 nm, a finding we support by effective mass calculations. In spite of this, CdS shell growth generally decreases the photoluminescence quantum yield of PbS/CdS core/shell QDs as compared to PbS core QDs. This suggests that photoluminescence quenching is mainly caused by defects at the PbS/CdS interface.

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Chicago
Chiluka, Laxmi, Willem Walravens, Qiang Zhao, André Vantomme, Pieter Geiregat, and Zeger Hens. 2016. “PbS/CdS Core/Shell Quantum Dots by Additive, Layer-by-layer Shell Growth.” Chemistry of Materials 28 (19): 6953–6959.
APA
Chiluka, L., Walravens, W., Zhao, Q., Vantomme, A., Geiregat, P., & Hens, Z. (2016). PbS/CdS Core/Shell quantum dots by additive, layer-by-layer shell growth. CHEMISTRY OF MATERIALS, 28(19), 6953–6959.
Vancouver
1.
Chiluka L, Walravens W, Zhao Q, Vantomme A, Geiregat P, Hens Z. PbS/CdS Core/Shell quantum dots by additive, layer-by-layer shell growth. CHEMISTRY OF MATERIALS. 2016;28(19):6953–9.
MLA
Chiluka, Laxmi, Willem Walravens, Qiang Zhao, et al. “PbS/CdS Core/Shell Quantum Dots by Additive, Layer-by-layer Shell Growth.” CHEMISTRY OF MATERIALS 28.19 (2016): 6953–6959. Print.
@article{8115465,
  abstract     = {We demonstrate additive shelling of PbS core quantum dots by CdS using room-temperature colloidal atomic layer deposition. Combining in-depth electron microscopy, absorption spectroscopy and elemental analysis, we present a structural model of the PbS/CdS core/shell quantum dots after each of the successive colloidal ALD cycles. In particular, we find that such core/shell quantum dots are cation-rich and we argue that this nonstoichiometry should be attributed to a Cd-excess at the outer surface. Analyzing various PbS/CdS core/shell QDs, we demonstrate that CdS shells have no effect on the energy of the PbS band-edge transition for PbS core QDs larger than \ensuremath{\asymp}4 nm, a finding we support by effective mass calculations. In spite of this, CdS shell growth generally decreases the photoluminescence quantum yield of PbS/CdS core/shell QDs as compared to PbS core QDs. This suggests that photoluminescence quenching is mainly caused by defects at the PbS/CdS interface.},
  author       = {Chiluka, Laxmi and Walravens, Willem and Zhao, Qiang and Vantomme, Andr{\'e} and Geiregat, Pieter and Hens, Zeger},
  issn         = {0897-4756},
  journal      = {CHEMISTRY OF MATERIALS},
  language     = {eng},
  number       = {19},
  pages        = {6953--6959},
  title        = {PbS/CdS Core/Shell quantum dots by additive, layer-by-layer shell growth},
  url          = {http://dx.doi.org/10.1021/acs.chemmater.6b02638},
  volume       = {28},
  year         = {2016},
}

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