Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties

We study the details of electronic transport related to the atomistic structure of silicon quantum dots embedded in a silicon dioxide matrix using ab initio calculations of the density of states. Several structural and composition features of quantum dots (QDs), such as diameter and amorphization le...

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Autores: Garcia-Castello, Nuria, Illera Robles, Sergio, Guerra, Roberto, Prades García, Juan Daniel, Ossicini, Stefano, Cirera Hernández, Albert
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/49046
Acceso en línea:https://hdl.handle.net/2445/49046
Access Level:acceso abierto
Palabra clave:Transport d'electrons
Semiconductors
Electrònica quàntica
Nanoelectrònica
Teoria quàntica
Optoelectrònica
Electron transport
Quantum electronics
Nanoelectronics
Quantum theory
Optoelectronics
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spelling Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport propertiesGarcia-Castello, NuriaIllera Robles, SergioGuerra, RobertoPrades García, Juan DanielOssicini, StefanoCirera Hernández, AlbertTransport d'electronsSemiconductorsElectrònica quànticaNanoelectrònicaTeoria quànticaOptoelectrònicaElectron transportSemiconductorsQuantum electronicsNanoelectronicsQuantum theoryOptoelectronicsWe study the details of electronic transport related to the atomistic structure of silicon quantum dots embedded in a silicon dioxide matrix using ab initio calculations of the density of states. Several structural and composition features of quantum dots (QDs), such as diameter and amorphization level, are studied and correlated with transport under transfer Hamiltonian formalism. The current is strongly dependent on the QD density of states and on the conduction gap, both dependent on the dot diameter. In particular, as size increases, the available states inside the QD increase, while the QD band gap decreases due to relaxation of quantum confinement. Both effects contribute to increasing the current with the dot size. Besides, valence band offset between the band edges of the QD and the silica, and conduction band offset in a minor grade, increases with the QD diameter up to the theoretical value corresponding to planar heterostructures, thus decreasing the tunneling transmission probability and hence the total current. We discuss the influence of these parameters on electron and hole transport, evidencing a correlation between the electron (hole) barrier value and the electron (hole) current, and obtaining a general enhancement of the electron (hole) transport for larger (smaller) QD. Finally, we show that crystalline and amorphous structures exhibit enhanced probability of hole and electron current, respectively.(FP7/2007-2013), Grant Agreement No. 245977American Physical Society2013info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/49046Articles publicats en revistes (Enginyeria Electrònica i Biomèdica)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésinfo:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.88.075322Reproducció del document publicat a: http://dx.doi.org/ 10.1103/PhysRevB.88.075322Physical Review B, 2013, vol. 88, num. 7, p. 075322-1-075322-11info:eu-repo/grantAgreement/EC/FP7/245977(c) American Physical Society, 2013info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/490462026-05-27T06:46:51Z
dc.title.none.fl_str_mv Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
title Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
spellingShingle Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
Garcia-Castello, Nuria
Transport d'electrons
Semiconductors
Electrònica quàntica
Nanoelectrònica
Teoria quàntica
Optoelectrònica
Electron transport
Semiconductors
Quantum electronics
Nanoelectronics
Quantum theory
Optoelectronics
title_short Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
title_full Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
title_fullStr Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
title_full_unstemmed Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
title_sort Silicon quantum dots embedded in a SiO2 matrix: From structural study to carrier transport properties
dc.creator.none.fl_str_mv Garcia-Castello, Nuria
Illera Robles, Sergio
Guerra, Roberto
Prades García, Juan Daniel
Ossicini, Stefano
Cirera Hernández, Albert
author Garcia-Castello, Nuria
author_facet Garcia-Castello, Nuria
Illera Robles, Sergio
Guerra, Roberto
Prades García, Juan Daniel
Ossicini, Stefano
Cirera Hernández, Albert
author_role author
author2 Illera Robles, Sergio
Guerra, Roberto
Prades García, Juan Daniel
Ossicini, Stefano
Cirera Hernández, Albert
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Transport d'electrons
Semiconductors
Electrònica quàntica
Nanoelectrònica
Teoria quàntica
Optoelectrònica
Electron transport
Semiconductors
Quantum electronics
Nanoelectronics
Quantum theory
Optoelectronics
topic Transport d'electrons
Semiconductors
Electrònica quàntica
Nanoelectrònica
Teoria quàntica
Optoelectrònica
Electron transport
Semiconductors
Quantum electronics
Nanoelectronics
Quantum theory
Optoelectronics
description We study the details of electronic transport related to the atomistic structure of silicon quantum dots embedded in a silicon dioxide matrix using ab initio calculations of the density of states. Several structural and composition features of quantum dots (QDs), such as diameter and amorphization level, are studied and correlated with transport under transfer Hamiltonian formalism. The current is strongly dependent on the QD density of states and on the conduction gap, both dependent on the dot diameter. In particular, as size increases, the available states inside the QD increase, while the QD band gap decreases due to relaxation of quantum confinement. Both effects contribute to increasing the current with the dot size. Besides, valence band offset between the band edges of the QD and the silica, and conduction band offset in a minor grade, increases with the QD diameter up to the theoretical value corresponding to planar heterostructures, thus decreasing the tunneling transmission probability and hence the total current. We discuss the influence of these parameters on electron and hole transport, evidencing a correlation between the electron (hole) barrier value and the electron (hole) current, and obtaining a general enhancement of the electron (hole) transport for larger (smaller) QD. Finally, we show that crystalline and amorphous structures exhibit enhanced probability of hole and electron current, respectively.
publishDate 2013
dc.date.none.fl_str_mv 2013
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/49046
url https://hdl.handle.net/2445/49046
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.88.075322
Reproducció del document publicat a: http://dx.doi.org/ 10.1103/PhysRevB.88.075322
Physical Review B, 2013, vol. 88, num. 7, p. 075322-1-075322-11
info:eu-repo/grantAgreement/EC/FP7/245977
dc.rights.none.fl_str_mv (c) American Physical Society, 2013
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) American Physical Society, 2013
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv Articles publicats en revistes (Enginyeria Electrònica i Biomèdica)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,301603

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