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Title: The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form

Abstract

Optical properties of as-deposited and annealed thin films composed of three-dimensional arrays of sphalerite-type ZnSe and CdSe quantum dots (QDs), synthesized by chemical deposition, were investigated. Neglecting the S-D mixing of hole states, the lowest 'band to band' transitions in very small nanoclusters and in bulk-like clusters may be assigned as 1S{yields}1S and 1S{sub {delta}}{yields}1S, and are split by spin-orbit (SO) splitting energy of the bulk material-{delta}. The splitting energy between these transitions was found to be insensitive to QD size variations, which could be explained assuming that 1S hole states arising from valence band {gamma}{sub 7} and {gamma}{sub 8} components do not mix with higher angular momentum states and shift together to higher energies coupled via the isotropic hole mass. This implies significant difference between the SO splitting energies in the two semiconductors. Accounting for S-D mixing of hole states, the observed transitions may be attributed to the fundamental ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}) ones. The observed 'splittings' thus do not correspond exactly to SO splitting energy in both semiconductors, but are complex functions of it, as exact position of each hole energy level depends, besides on {delta}, also on other material-characteristicmore » parameters. - Graphical abstract: Accounting for S-D mixing of hole states, the observed optical transitions in very small sphalerite-type ZnSe and CdSe nanoclusters are attributed to the ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}). The 'splittings' do not correspond to SO splitting energy, but are complex functions of it.« less

Authors:
 [1]
  1. Faculty of Natural Sciences and Mathematics, Institute of Chemistry, Saints Cyril and Methodius University, PO Box 162, 1001 Skopje (Macedonia, The Former Yugoslav Republic of)
Publication Date:
OSTI Identifier:
21128398
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 181; Journal Issue: 8; Other Information: DOI: 10.1016/j.jssc.2008.03.038; PII: S0022-4596(08)00181-3; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANNEALING; CADMIUM SELENIDES; DEPOSITION; GROUND STATES; HOLES; L-S COUPLING; OPTICAL PROPERTIES; QUANTUM DOTS; SEMICONDUCTOR MATERIALS; SOLIDS; THIN FILMS; THREE-DIMENSIONAL CALCULATIONS; ZINC SELENIDES

Citation Formats

Pejova, Biljana. The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form. United States: N. p., 2008. Web. doi:10.1016/j.jssc.2008.03.038.
Pejova, Biljana. The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form. United States. https://doi.org/10.1016/j.jssc.2008.03.038
Pejova, Biljana. Fri . "The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form". United States. https://doi.org/10.1016/j.jssc.2008.03.038.
@article{osti_21128398,
title = {The higher excited electronic states and spin-orbit splitting of the valence band in three-dimensional assemblies of close-packed ZnSe and CdSe quantum dots in thin film form},
author = {Pejova, Biljana},
abstractNote = {Optical properties of as-deposited and annealed thin films composed of three-dimensional arrays of sphalerite-type ZnSe and CdSe quantum dots (QDs), synthesized by chemical deposition, were investigated. Neglecting the S-D mixing of hole states, the lowest 'band to band' transitions in very small nanoclusters and in bulk-like clusters may be assigned as 1S{yields}1S and 1S{sub {delta}}{yields}1S, and are split by spin-orbit (SO) splitting energy of the bulk material-{delta}. The splitting energy between these transitions was found to be insensitive to QD size variations, which could be explained assuming that 1S hole states arising from valence band {gamma}{sub 7} and {gamma}{sub 8} components do not mix with higher angular momentum states and shift together to higher energies coupled via the isotropic hole mass. This implies significant difference between the SO splitting energies in the two semiconductors. Accounting for S-D mixing of hole states, the observed transitions may be attributed to the fundamental ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}) ones. The observed 'splittings' thus do not correspond exactly to SO splitting energy in both semiconductors, but are complex functions of it, as exact position of each hole energy level depends, besides on {delta}, also on other material-characteristic parameters. - Graphical abstract: Accounting for S-D mixing of hole states, the observed optical transitions in very small sphalerite-type ZnSe and CdSe nanoclusters are attributed to the ground state-(1S{sub 3/2}, 1S{sub e}) and the ground state-(1S{sub 1/2}, 1S{sub e}). The 'splittings' do not correspond to SO splitting energy, but are complex functions of it.},
doi = {10.1016/j.jssc.2008.03.038},
url = {https://www.osti.gov/biblio/21128398}, journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = 8,
volume = 181,
place = {United States},
year = {2008},
month = {8}
}