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Metal-passivated PbS nanoparticles : Fabrication and characterization

Tchaplyguine, M. LU ; Mikkelä, M. H. LU ; Mårsell, E. LU ; Polley, C. LU ; Mikkelsen, A. LU ; Zhang, W. LU ; Yartsev, A. LU ; Hetherington, C. J D LU ; Wallenberg, Reine LU and Björneholm, O. LU (2017) In Physical Chemistry Chemical Physics 19(10). p.7252-7261
Abstract

Organic-shell-free PbS nanoparticles have been produced in the size range relevant for quantum-dot solar cells (QDSCs) by a vapor aggregation method involving magnetron reactive sputtering. This method creates a beam of free 5-10 nm particles in a vacuum. The dimensions of the particles were estimated after their deposition on a substrate by imaging them using ex situ SEM and HRTEM electron microscopy. The particle structure and chemical composition could be deduced "on the fly", prior to deposition, using X-ray photoelectron spectroscopy (XPS) with tunable synchrotron radiation. Our XPS results suggest that under certain conditions it is possible to fabricate particles with a semiconductor core and 1 to 2 monolayer shells of metallic... (More)

Organic-shell-free PbS nanoparticles have been produced in the size range relevant for quantum-dot solar cells (QDSCs) by a vapor aggregation method involving magnetron reactive sputtering. This method creates a beam of free 5-10 nm particles in a vacuum. The dimensions of the particles were estimated after their deposition on a substrate by imaging them using ex situ SEM and HRTEM electron microscopy. The particle structure and chemical composition could be deduced "on the fly", prior to deposition, using X-ray photoelectron spectroscopy (XPS) with tunable synchrotron radiation. Our XPS results suggest that under certain conditions it is possible to fabricate particles with a semiconductor core and 1 to 2 monolayer shells of metallic lead. For this case the absolute energy of the highest occupied molecular orbital (HOMO) in PbS has been determined to be (5.0 ± 0.5) eV below the vacuum level. For such particles deposited on a substrate HRTEM has confirmed the XPS-based conclusions on the crystalline PbS structure of the semiconductor core. Absorption spectroscopy on the deposited film has given a value of ∼1 eV for the lowest exciton. Together with the valence XPS results this has allowed us to reconstruct the energy level scheme of the particles. The results obtained are discussed in the context of the properties of PbS QDSCs.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
19
issue
10
pages
10 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85015296773
  • wos:000396148600039
ISSN
1463-9076
DOI
10.1039/c6cp06870g
language
English
LU publication?
yes
id
667a3533-b2ab-4106-9625-cb6a97167918
date added to LUP
2017-03-30 09:47:25
date last changed
2018-01-07 11:57:32
@article{667a3533-b2ab-4106-9625-cb6a97167918,
  abstract     = {<p>Organic-shell-free PbS nanoparticles have been produced in the size range relevant for quantum-dot solar cells (QDSCs) by a vapor aggregation method involving magnetron reactive sputtering. This method creates a beam of free 5-10 nm particles in a vacuum. The dimensions of the particles were estimated after their deposition on a substrate by imaging them using ex situ SEM and HRTEM electron microscopy. The particle structure and chemical composition could be deduced "on the fly", prior to deposition, using X-ray photoelectron spectroscopy (XPS) with tunable synchrotron radiation. Our XPS results suggest that under certain conditions it is possible to fabricate particles with a semiconductor core and 1 to 2 monolayer shells of metallic lead. For this case the absolute energy of the highest occupied molecular orbital (HOMO) in PbS has been determined to be (5.0 ± 0.5) eV below the vacuum level. For such particles deposited on a substrate HRTEM has confirmed the XPS-based conclusions on the crystalline PbS structure of the semiconductor core. Absorption spectroscopy on the deposited film has given a value of ∼1 eV for the lowest exciton. Together with the valence XPS results this has allowed us to reconstruct the energy level scheme of the particles. The results obtained are discussed in the context of the properties of PbS QDSCs.</p>},
  author       = {Tchaplyguine, M. and Mikkelä, M. H. and Mårsell, E. and Polley, C. and Mikkelsen, A. and Zhang, W. and Yartsev, A. and Hetherington, C. J D and Wallenberg, Reine and Björneholm, O.},
  issn         = {1463-9076},
  language     = {eng},
  month        = {02},
  number       = {10},
  pages        = {7252--7261},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Metal-passivated PbS nanoparticles : Fabrication and characterization},
  url          = {http://dx.doi.org/10.1039/c6cp06870g},
  volume       = {19},
  year         = {2017},
}