Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy
Positron annihilation lifetime spectroscopy and positron-electron momentum density (PEMD) studies on multilayers of PbSe nanocrystals (NCs), supported by transmission electron microscopy, show that positrons are strongly trapped at NC surfaces, where they provide insight into the surface composition...
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2013-08-01
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Series: | APL Materials |
Online Access: | http://link.aip.org/link/doi/10.1063/1.4818001 |
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doaj-00f2cd0b83f7409187c4abdd881756d62020-11-25T00:54:16ZengAIP Publishing LLCAPL Materials2166-532X2013-08-011202211102211110.1063/1.4818001Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopyL. ChaiW. Al-SawaiY. GaoA. J. HoutepenP. E. MijnarendsB. BarbielliniH. SchutL. C. van SchaarenburgM. A. van HuisL. RavelliW. EggerS. KaprzykA. BansilS. W. H. EijtPositron annihilation lifetime spectroscopy and positron-electron momentum density (PEMD) studies on multilayers of PbSe nanocrystals (NCs), supported by transmission electron microscopy, show that positrons are strongly trapped at NC surfaces, where they provide insight into the surface composition and electronic structure of PbSe NCs. Our analysis indicates abundant annihilation of positrons with Se electrons at the NC surfaces and with O electrons of the oleic ligands bound to Pb ad-atoms at the NC surfaces, which demonstrates that positrons can be used as a sensitive probe to investigate the surface physics and chemistry of nanocrystals inside multilayers. Ab initio electronic structure calculations provide detailed insight in the valence and semi-core electron contributions to the positron-electron momentum density of PbSe. Both lifetime and PEMD are found to correlate with changes in the particle morphology characteristic of partial ligand removal.http://link.aip.org/link/doi/10.1063/1.4818001 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
L. Chai W. Al-Sawai Y. Gao A. J. Houtepen P. E. Mijnarends B. Barbiellini H. Schut L. C. van Schaarenburg M. A. van Huis L. Ravelli W. Egger S. Kaprzyk A. Bansil S. W. H. Eijt |
spellingShingle |
L. Chai W. Al-Sawai Y. Gao A. J. Houtepen P. E. Mijnarends B. Barbiellini H. Schut L. C. van Schaarenburg M. A. van Huis L. Ravelli W. Egger S. Kaprzyk A. Bansil S. W. H. Eijt Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy APL Materials |
author_facet |
L. Chai W. Al-Sawai Y. Gao A. J. Houtepen P. E. Mijnarends B. Barbiellini H. Schut L. C. van Schaarenburg M. A. van Huis L. Ravelli W. Egger S. Kaprzyk A. Bansil S. W. H. Eijt |
author_sort |
L. Chai |
title |
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy |
title_short |
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy |
title_full |
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy |
title_fullStr |
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy |
title_full_unstemmed |
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy |
title_sort |
surfaces of colloidal pbse nanocrystals probed by thin-film positron annihilation spectroscopy |
publisher |
AIP Publishing LLC |
series |
APL Materials |
issn |
2166-532X |
publishDate |
2013-08-01 |
description |
Positron annihilation lifetime spectroscopy and positron-electron momentum density (PEMD) studies on multilayers of PbSe nanocrystals (NCs), supported by transmission electron microscopy, show that positrons are strongly trapped at NC surfaces, where they provide insight into the surface composition and electronic structure of PbSe NCs. Our analysis indicates abundant annihilation of positrons with Se electrons at the NC surfaces and with O electrons of the oleic ligands bound to Pb ad-atoms at the NC surfaces, which demonstrates that positrons can be used as a sensitive probe to investigate the surface physics and chemistry of nanocrystals inside multilayers. Ab initio electronic structure calculations provide detailed insight in the valence and semi-core electron contributions to the positron-electron momentum density of PbSe. Both lifetime and PEMD are found to correlate with changes in the particle morphology characteristic of partial ligand removal. |
url |
http://link.aip.org/link/doi/10.1063/1.4818001 |
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