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Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets

The exciton states and their influence on the optical absorption spectrum of CdSe and PbS nanoplatelets (NPLs) are considered theoretically in this paper. The problem is discussed in cases of strong, intermediate, and weak size quantization regimes of charge carrier motion in NPLs. For each size qua...

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Autores principales: Baghdasaryan, Davit A., Harutyunyan, Volodya A., Hayrapetyan, David B., Kazaryan, Eduard M., Baskoutas, Sotirios, Sarkisyan, Hayk A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611409/
https://www.ncbi.nlm.nih.gov/pubmed/36296880
http://dx.doi.org/10.3390/nano12203690
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author Baghdasaryan, Davit A.
Harutyunyan, Volodya A.
Hayrapetyan, David B.
Kazaryan, Eduard M.
Baskoutas, Sotirios
Sarkisyan, Hayk A.
author_facet Baghdasaryan, Davit A.
Harutyunyan, Volodya A.
Hayrapetyan, David B.
Kazaryan, Eduard M.
Baskoutas, Sotirios
Sarkisyan, Hayk A.
author_sort Baghdasaryan, Davit A.
collection PubMed
description The exciton states and their influence on the optical absorption spectrum of CdSe and PbS nanoplatelets (NPLs) are considered theoretically in this paper. The problem is discussed in cases of strong, intermediate, and weak size quantization regimes of charge carrier motion in NPLs. For each size quantization regime, the corresponding potential that adequately describes the electron–hole interaction in this mode of space quantization of charge carriers is chosen. The single-particle energy spectra and corresponding wave functions for strong intermediate and weak size quantization regimes have been revealed. The dependence of material parameters on the number of monolayers in the sample has been considered. The related selection rules and the dependence of the absorption coefficient on the frequency and polarization direction of the incident light wave were obtained. The interband transition threshold energy dependencies were obtained for each size quantization regime. The effect of dielectric coefficient mismatch and different models of electron–hole interaction potentials have been studied in CdSe and PbS NPLs. It is also shown that with an increase in the linear dimensions of the structure, the threshold frequency of absorption decreases. The binding energies and absorption coefficient results for NPL with different thicknesses agree with the experimental data. The values of the absorption exciton peaks measured experimentally are close to our calculated values for CdSe and PbS samples.
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spelling pubmed-96114092022-10-28 Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets Baghdasaryan, Davit A. Harutyunyan, Volodya A. Hayrapetyan, David B. Kazaryan, Eduard M. Baskoutas, Sotirios Sarkisyan, Hayk A. Nanomaterials (Basel) Article The exciton states and their influence on the optical absorption spectrum of CdSe and PbS nanoplatelets (NPLs) are considered theoretically in this paper. The problem is discussed in cases of strong, intermediate, and weak size quantization regimes of charge carrier motion in NPLs. For each size quantization regime, the corresponding potential that adequately describes the electron–hole interaction in this mode of space quantization of charge carriers is chosen. The single-particle energy spectra and corresponding wave functions for strong intermediate and weak size quantization regimes have been revealed. The dependence of material parameters on the number of monolayers in the sample has been considered. The related selection rules and the dependence of the absorption coefficient on the frequency and polarization direction of the incident light wave were obtained. The interband transition threshold energy dependencies were obtained for each size quantization regime. The effect of dielectric coefficient mismatch and different models of electron–hole interaction potentials have been studied in CdSe and PbS NPLs. It is also shown that with an increase in the linear dimensions of the structure, the threshold frequency of absorption decreases. The binding energies and absorption coefficient results for NPL with different thicknesses agree with the experimental data. The values of the absorption exciton peaks measured experimentally are close to our calculated values for CdSe and PbS samples. MDPI 2022-10-20 /pmc/articles/PMC9611409/ /pubmed/36296880 http://dx.doi.org/10.3390/nano12203690 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Baghdasaryan, Davit A.
Harutyunyan, Volodya A.
Hayrapetyan, David B.
Kazaryan, Eduard M.
Baskoutas, Sotirios
Sarkisyan, Hayk A.
Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title_full Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title_fullStr Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title_full_unstemmed Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title_short Exciton States and Optical Absorption in CdSe and PbS Nanoplatelets
title_sort exciton states and optical absorption in cdse and pbs nanoplatelets
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611409/
https://www.ncbi.nlm.nih.gov/pubmed/36296880
http://dx.doi.org/10.3390/nano12203690
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