Cargando…
Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field
Using the effective mass approximation in a parabolic two-band model, we studied the effects of the geometrical parameters, on the electron and hole states, in two truncated conical quantum dots: (i) GaAs-(Ga,Al)As in the presence of a shallow donor impurity and under an applied magnetic field and (...
Autores principales: | , , , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8619694/ https://www.ncbi.nlm.nih.gov/pubmed/34835595 http://dx.doi.org/10.3390/nano11112832 |
_version_ | 1784605055591120896 |
---|---|
author | Pulgar-Velásquez, Lorenz Sierra-Ortega, José Vinasco, Juan A. Laroze, David Radu, Adrian Kasapoglu, Esin Restrepo, Ricardo L. Gil-Corrales, John A. Morales, Alvaro L. Duque, Carlos A. |
author_facet | Pulgar-Velásquez, Lorenz Sierra-Ortega, José Vinasco, Juan A. Laroze, David Radu, Adrian Kasapoglu, Esin Restrepo, Ricardo L. Gil-Corrales, John A. Morales, Alvaro L. Duque, Carlos A. |
author_sort | Pulgar-Velásquez, Lorenz |
collection | PubMed |
description | Using the effective mass approximation in a parabolic two-band model, we studied the effects of the geometrical parameters, on the electron and hole states, in two truncated conical quantum dots: (i) GaAs-(Ga,Al)As in the presence of a shallow donor impurity and under an applied magnetic field and (ii) CdSe–CdTe core–shell type-II quantum dot. For the first system, the impurity position and the applied magnetic field direction were chosen to preserve the system’s azimuthal symmetry. The finite element method obtains the solution of the Schrödinger equations for electron or hole with or without impurity with an adaptive discretization of a triangular mesh. The interaction of the electron and hole states is calculated in a first-order perturbative approximation. This study shows that the magnetic field and donor impurities are relevant factors in the optoelectronic properties of conical quantum dots. Additionally, for the CdSe–CdTe quantum dot, where, again, the axial symmetry is preserved, a switch between direct and indirect exciton is possible to be controlled through geometry. |
format | Online Article Text |
id | pubmed-8619694 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-86196942021-11-27 Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field Pulgar-Velásquez, Lorenz Sierra-Ortega, José Vinasco, Juan A. Laroze, David Radu, Adrian Kasapoglu, Esin Restrepo, Ricardo L. Gil-Corrales, John A. Morales, Alvaro L. Duque, Carlos A. Nanomaterials (Basel) Article Using the effective mass approximation in a parabolic two-band model, we studied the effects of the geometrical parameters, on the electron and hole states, in two truncated conical quantum dots: (i) GaAs-(Ga,Al)As in the presence of a shallow donor impurity and under an applied magnetic field and (ii) CdSe–CdTe core–shell type-II quantum dot. For the first system, the impurity position and the applied magnetic field direction were chosen to preserve the system’s azimuthal symmetry. The finite element method obtains the solution of the Schrödinger equations for electron or hole with or without impurity with an adaptive discretization of a triangular mesh. The interaction of the electron and hole states is calculated in a first-order perturbative approximation. This study shows that the magnetic field and donor impurities are relevant factors in the optoelectronic properties of conical quantum dots. Additionally, for the CdSe–CdTe quantum dot, where, again, the axial symmetry is preserved, a switch between direct and indirect exciton is possible to be controlled through geometry. MDPI 2021-10-25 /pmc/articles/PMC8619694/ /pubmed/34835595 http://dx.doi.org/10.3390/nano11112832 Text en © 2021 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 Pulgar-Velásquez, Lorenz Sierra-Ortega, José Vinasco, Juan A. Laroze, David Radu, Adrian Kasapoglu, Esin Restrepo, Ricardo L. Gil-Corrales, John A. Morales, Alvaro L. Duque, Carlos A. Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title | Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title_full | Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title_fullStr | Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title_full_unstemmed | Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title_short | Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field |
title_sort | shallow donor impurity states with excitonic contribution in gaas/algaas and cdte/cdse truncated conical quantum dots under applied magnetic field |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8619694/ https://www.ncbi.nlm.nih.gov/pubmed/34835595 http://dx.doi.org/10.3390/nano11112832 |
work_keys_str_mv | AT pulgarvelasquezlorenz shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT sierraortegajose shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT vinascojuana shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT larozedavid shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT raduadrian shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT kasapogluesin shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT restreporicardol shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT gilcorralesjohna shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT moralesalvarol shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield AT duquecarlosa shallowdonorimpuritystateswithexcitoniccontributioningaasalgaasandcdtecdsetruncatedconicalquantumdotsunderappliedmagneticfield |