Next Article in Journal
Field Emission Characterization of MoS2 Nanoflowers
Previous Article in Journal
Dibenzyl Disulfide Adsorption on Cationic Exchanged Faujasites: A DFT Study
Previous Article in Special Issue
Effects of Laser Plasma Formation on Quasi-Phase Matching of High-Order Harmonics from Nanoparticles and Atoms
Article Menu
Issue 5 (May) cover image

Export Article

Open AccessArticle

Inhomogeneous Broadening of the Exciton Band in Optical Absorption Spectra of InP/ZnS Nanocrystals

1
NANOTECH Centre, Ural Federal University, 19 Mira str., Ekaterinburg 620002, Russia
2
Institute of Metallurgy, Ural Branch of the Russian Academy of Sciences, 101 Amundsena str., Ekaterinburg 620016, Russia
*
Author to whom correspondence should be addressed.
Nanomaterials 2019, 9(5), 716; https://doi.org/10.3390/nano9050716
Received: 10 April 2019 / Revised: 2 May 2019 / Accepted: 7 May 2019 / Published: 9 May 2019
(This article belongs to the Special Issue Photophysics of Media Doped with Nanoobjects)
  |  
PDF [3191 KB, uploaded 9 May 2019]
  |  

Abstract

In this work, we have simulated the processes of broadening the first exciton band in optical absorption spectra (OA) for InP/ZnS ensembles of colloidal quantum dots (QDs). A phenomenological model has been proposed that takes into account the effects of the exciton–phonon interaction, and allows one to analyze the influence of the static and dynamic types of atomic disorder on the temperature changes in the spectral characteristics in question. To vary the degree of static disorder in the model system, we have used a parameter δ, which characterizes the QD dispersion in size over the ensemble. We have also calculated the temperature shifts of the maxima and changes in the half-width for the exciton peaks in single nanocrystals (δ = 0), as well as for the integrated OA bands in the QD ensembles with different values of δ = 0.6–17%. The simulation results and the OA spectra data measured for InP/ZnS nanocrystals of 2.1 nm (δ = 11.1%) and 2.3 nm (δ = 17.3%), are in good mutual agreement in the temperature range of 6.5 K–RT. It has been shown that the contribution of static disorder to the observed inhomogeneous broadening of the OA bands for the QDs at room temperature exceeds 90%. The computational experiments performed indicate that the temperature shift of the maximum for the integrated OA band coincides with that for the exciton peak in a single nanocrystal. In this case, a reliable estimate of the parameters of the fundamental exciton–phonon interaction can be made. Simultaneously, the values of the specified parameters, calculated from the temperature broadening of the OA spectra, can be significantly different from the true ones due to the effects of static atomic disorder in real QD ensembles. View Full-Text
Keywords: colloidal quantum dots; core/shell; exciton absorption; half-width; ensemble; inhomogeneous and homogeneous broadening; static and dynamic disorder colloidal quantum dots; core/shell; exciton absorption; half-width; ensemble; inhomogeneous and homogeneous broadening; static and dynamic disorder
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Savchenko, S.S.; Weinstein, I.A. Inhomogeneous Broadening of the Exciton Band in Optical Absorption Spectra of InP/ZnS Nanocrystals. Nanomaterials 2019, 9, 716.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Nanomaterials EISSN 2079-4991 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top