liu.seSearch for publications in DiVA
Change search
Link to record
Permanent link

Direct link
BETA
Ribeiro, Luiz AntonioORCID iD iconorcid.org/0000-0001-7468-2946
Alternative names
Publications (10 of 13) Show all publications
Silva, G. G., da Cunha, W. F., de Sousa Junior, R. T., Almeida Fonseca, A. L., Ribeiro, L. A. & Magela e Silva, G. (2018). Influence of quasi-particle density over polaron mobility in armchair graphene nanoribbons. Physical Chemistry, Chemical Physics - PCCP, 20(24), 16712-16718
Open this publication in new window or tab >>Influence of quasi-particle density over polaron mobility in armchair graphene nanoribbons
Show others...
2018 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 24, p. 16712-16718Article in journal (Refereed) Published
Abstract [en]

An important aspect concerning the performance of armchair graphene nanoribbons (AGNRs) as materials for conceiving electronic devices is related to the mobility of charge carriers in these systems. When several polarons are considered in the system, a quasi-particle wave function can be affected by that of its neighbor provided the two are close enough. As the overlap may affect the transport of the carrier, the question concerning how the density of polarons affect its mobility arises. In this work, we investigate such dependence for semiconducting AGNRs in the scope of nonadiabatic molecular dynamics. Our results unambiguously show an impact of the density on both the stability and average velocity of the quasi-particles. We have found a phase transition between regimes where increasing density stops inhibiting and starts promoting mobility; densities higher than 7 polarons per 45 angstrom present increasing mean velocity with increasing density. We have also established three different regions relating electric field and average velocity. For the lowest electric field regime, surpassing the aforementioned threshold results in overcoming the 0.3 angstrom fs(-1) limit, thus representing a transition between subsonic and supersonic regimes. For the highest of the electric fields, density effects alone are responsible for a stunning difference of 1.5 angstrom fs(-1) in the mean carrier velocity.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2018
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-149710 (URN)10.1039/c8cp02373e (DOI)000436032900042 ()29878013 (PubMedID)
Note

Funding Agencies|CNPq; CAPES; FAP-DF; CENAPAD-SP; Brazilian Ministry of Planning, Development and Management [005/2016, 11/2016]; DPGU - Brazilian Union Public Defender [066/2016]; FAP-DF [0193.000.942/2015, 193.001.511/2017]

Available from: 2018-07-24 Created: 2018-07-24 Last updated: 2019-06-27
Ribeiro, L. A. & Stafström, S. (2016). Impact of the electron-phonon coupling symmetry on the polaron stability and mobility in organic molecular semiconductors. Physical Chemistry, Chemical Physics - PCCP, 18(3), 1386-1391
Open this publication in new window or tab >>Impact of the electron-phonon coupling symmetry on the polaron stability and mobility in organic molecular semiconductors
2016 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 3, p. 1386-1391Article in journal (Refereed) Published
Abstract [en]

The influence of the interplay between symmetric and antisymmetric inter-molecular electron-phonon (e-ph) coupling mechanisms on the polaron stability and mobility in organic semiconductors has been theoretically investigated at a molecular level. A semi-empirical Holstein-Peierls model is used which in addition to the symmetric and antisymmetric inter-molecular e-ph interactions also includes an antisymmetric intra-molecular e-ph coupling. Our results show that the symmetric e-ph coupling plays the role of destabilizing the polaron as a result of temperature induced phonons that, via the symmetric coupling, affects the charge distribution of the polaron. Considering this kind of coupling, the parameter space for which the polaron is dynamically stable is strongly temperature-dependent. For the combination of symmetric e-ph coupling strength and temperature, which results in a stable polaron, the velocity of the polaron, and therefore also the charge carrier mobility, is not affected by the symmetric e-ph coupling strength.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2016
National Category
Physical Chemistry
Identifiers
urn:nbn:se:liu:diva-125686 (URN)10.1039/c5cp06577a (DOI)000369482100002 ()26674995 (PubMedID)
Note

Funding Agencies|Swedish Research Council (VR); Brazilian Research Council CAPES; Brazilian Research Council FAPDF

Available from: 2016-03-01 Created: 2016-02-29 Last updated: 2019-06-27
Passos Abreu, A. V., Fernando Teixeira, J., Luciano de Almeida Fonseca, A., Gargano, R., Magela e Silva, G. & Ribeiro, L. A. (2016). Impact of the Electron-Phonon Interactions on the Polaron Dynamics in Graphene Nanoribbons. Journal of Physical Chemistry A, 120(27), 4901-4906
Open this publication in new window or tab >>Impact of the Electron-Phonon Interactions on the Polaron Dynamics in Graphene Nanoribbons
Show others...
2016 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 120, no 27, p. 4901-4906Article in journal (Refereed) Published
Abstract [en]

The influence of the electron-phonon (e-ph) interactions on the filed-included polaron dynamics in armchair graphene nanoribbons (GNRs) is theoretically investigated in the scope of a two-dimensional tight-binding model. The results show that the localization of the polaronic charge increases when the strength of e-ph coupling also increases. Consequently, the polaron saturation velocity decreases for higher e-ph coupling strengths. Interestingly, the interplay between the e-ph coupling strength and the GNR width changes substantially the polaron dynamics properties.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-130656 (URN)10.1021/acs.jpca.5b12482 (DOI)000379988900034 ()27050874 (PubMedID)
Note

Funding Agencies|FAP-DF grant [0193.000942/2015]; Brazilian Research Council CNPq; Brazilian Research Council CAPES; Brazilian Research Council FAPDF; Brazilian Research Council FINATEC

Available from: 2016-08-22 Created: 2016-08-19 Last updated: 2019-06-27
Ribeiro Junior, L. A., Santiago de Brito, S. & Henrique de Oliveira Neto, P. (2016). Trap-assisted charge transport at conjugated polymer interfaces. Chemical Physics Letters, 644, 121-126
Open this publication in new window or tab >>Trap-assisted charge transport at conjugated polymer interfaces
2016 (English)In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 644, p. 121-126Article in journal (Refereed) Published
Abstract [en]

The trap-assisted charge transport in conjugated polymers is numerically investigated in the framework of a one-dimensional tight-binding model. Our findings show that a polaron trapped within an interchain region can be released migrating between the chains at low temperature regimes. Conversely, a trapped bipolaron cannot be released even considering high temperature values. Interestingly, for systems containing more than one polaron, the formation of trapped states is avoided and there is no charge transfer between the chains. Considering more than one bipolaron, the generation of trapped states occurs and a bipolaron can migrates between the chains. (C) 2015 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2016
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:liu:diva-124631 (URN)10.1016/j.cplett.2015.12.006 (DOI)000368264500003 ()
Note

Funding Agencies|Swedish Research Council (VR); Brazilian Research Council CNPq; Brazilian Research Council CAPES; Brazilian Research Council FAPDF

Available from: 2016-02-09 Created: 2016-02-08 Last updated: 2019-06-27
Ribeiro, L. A., Ferreira da Cunha, W., de Almeida Fonseca, A. L., Garganoc, R. & Magela e Silva, G. (2015). Concentration effects on intrachain polaron recombination in conjugated polymers. Physical Chemistry, Chemical Physics - PCCP, 17(2), 1299-1308
Open this publication in new window or tab >>Concentration effects on intrachain polaron recombination in conjugated polymers
Show others...
2015 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 2, p. 1299-1308Article in journal (Refereed) Published
Abstract [en]

The influence of different charge carrier concentrations on the recombination dynamics between oppositely charged polarons is numerically investigated using a modified version of the Su-Schrieffer-Heeger (SSH) model that includes an external electric field and electron-electron interactions. Our findings show that the external electric field can play the role of avoiding the formation of excited states (polaron-exciton and neutral excitation) leading the system to a dimerized lattice. Interestingly, depending on a suitable balance between the polaron concentration and the electric field strength, the recombination mechanism can form stable polaron-excitons or neutral excitations. These results may provide guidance to improve the electroluminescence efficiency in Polymer Light Emitting Diodes.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-113492 (URN)10.1039/c4cp04514a (DOI)000346236000067 ()25423278 (PubMedID)
Note

Funding Agencies|Swedish Research Council (VR); Swedish National Infrastructure for Computing (SNIC); Brazilian Research Council CNPq; Brazilian Research Council CAPES; Brazilian Research Council FINATEC

Available from: 2015-01-19 Created: 2015-01-19 Last updated: 2019-06-27
Ferreira Monteiro, F., Lima Azevedo, D., Carlos da Silva, E., Ribeiro Jr., L. A. & Luciano de Almeida Fonseca, A. (2015). Encapsulated beta-carotene in ZnO nanotubes: Theoretical insight into the stabilization dynamics. Chemical Physics Letters, 636, 62-66
Open this publication in new window or tab >>Encapsulated beta-carotene in ZnO nanotubes: Theoretical insight into the stabilization dynamics
Show others...
2015 (English)In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 636, p. 62-66Article in journal (Refereed) Published
Abstract [en]

The stabilization dynamics of a molecular dye (beta-carotene) encapsulated in single-wall zinc oxide nanotubes (ZnONTs) is theoretically investigated in the scope of molecular dynamics and density functional theory simulations. Our findings show that the beta-carotene encapsulation in ZnONTs is an energetically favorable process. Once encapsulated, this molecular dye remains close to the ZnONT wall, in accordance with recent experimental reports. Interestingly, the interaction between the beta-carotene and ZnONT can form a charge delocalization state, where an amount of charge concentrated on beta-carotene is transferred to ZnONT. (C) 2015 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2015
National Category
Physical Chemistry
Identifiers
urn:nbn:se:liu:diva-122116 (URN)10.1016/j.cplett.2015.07.025 (DOI)000361649900011 ()
Note

Funding Agencies|Swedish Research Council (VR); Brazilian Research Council CNPq

Available from: 2015-10-19 Created: 2015-10-19 Last updated: 2019-06-27
Ferreira da Cunha, W., Ribeiro, L. A., Luciano de Almeida Fonseca, A., Gargano, R. & Magela e Silva, G. (2015). Impurity effects on polaron dynamics in graphene nanoribbons. Carbon, 91, 171-177
Open this publication in new window or tab >>Impurity effects on polaron dynamics in graphene nanoribbons
Show others...
2015 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 91, p. 171-177Article in journal (Refereed) Published
Abstract [en]

The impurity effects on the dynamics of polarons in armchair graphene nanoribbons are numerically investigated in the scope of a two-dimensional tight-binding approach with lattice relaxation. The results show that the presence of an impurity changes significantly the net charge distribution associated to the polaron structure. Moreover, the interplay between external electric field and the local impurities plays the role of drastically modifying the polaron dynamics. Interestingly, nanoribbons containing mobile polarons are noted to take place even when considering high impurity levels, which is associated with the highly conductive character of the graphene nanoribbons. This investigation may enlighten the understanding of the charge transport mechanism in carbon-based nanomaterials. (C) 2015 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2015
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-120204 (URN)10.1016/j.carbon.2015.04.065 (DOI)000356554500019 ()
Available from: 2015-07-21 Created: 2015-07-20 Last updated: 2019-06-27
Antonio Ribeiro, L. & Stafström, S. (2015). Polaron stability in molecular semiconductors: theoretical insight into the impact of the temperature, electric field and the system dimensionality. Physical Chemistry, Chemical Physics - PCCP, 17(14), 8973-8982
Open this publication in new window or tab >>Polaron stability in molecular semiconductors: theoretical insight into the impact of the temperature, electric field and the system dimensionality
2015 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 14, p. 8973-8982Article in journal (Refereed) Published
Abstract [en]

A semi-empirical Holstein-Peierls model is used to study the temperature effects on the polaron stability in organic semiconductors at a molecular scale. The approach takes into account both intra- and intermolecular electron-lattice interactions and is aimed at describing charge transport in the system. Particularly, we present a systematic numerical investigation to characterize the influence of both temperature and electric field on the stability as well as mobility of the polaron. It is found that the parameter space for which the polaron is dynamically stable is quite limited and the variations in some of these parameters strongly depend on the temperature. The electric field can play a role in further localizing the charge causing a compression of the lattice distortions associated with the polaron, increasing thereby its stability, up to a field strength of approximately 2.0 mV angstrom(-1). Considering field strengths higher than this critical value, the polaron is annihilated spreading charge through the lattice. Furthermore, we have studied the polaron mobility as a function of the anisotropy of the system, going from a one-dimensional system via a highly anisotropic two-dimensional system to a uniform two-dimensional system. There is a clearly observed mobility edge for the polaron; it exhibits a high mobility in the one-dimensional system but as the coupling in the second dimension is turned on the polaron slows down and becomes immobile in the uniform system. The results provided by this transport mechanism are in good agreement with experimental observations and may provide guidance to improve the charge transport in organic optoelectronic devices.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015
National Category
Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-117397 (URN)10.1039/c4cp06028h (DOI)000351933600050 ()25746667 (PubMedID)
Funder
Swedish Research Council
Available from: 2015-04-24 Created: 2015-04-24 Last updated: 2019-06-27Bibliographically approved
Ribeiro, L. A., Ferreira da Cunha, W., Luciano de Almeida Fonseca, A., Magela e Silva, G. & Stafström, S. (2015). Transport of Polarons in Graphene Nanoribbons. Journal of Physical Chemistry Letters, 6(3), 510-514
Open this publication in new window or tab >>Transport of Polarons in Graphene Nanoribbons
Show others...
2015 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 6, no 3, p. 510-514Article in journal (Refereed) Published
Abstract [en]

The field-induced dynamics of polarons in armchair graphene nanoribbons (GNRs) is theoretically investigated in the framework of a two-dimensional tight-binding model with lattice relaxation. Our findings show that the semiconductor behavior, fundamental to polaron transport to take place, depends upon of a suitable balance between the GNR width and the electronphonon (eph) coupling strength. In a similar way, we found that the parameter space for which the polaron is dynamically stable is limited to an even narrower region of the GNR width and the eph coupling strength. Interestingly, the interplay between the external electric field and the eph coupling plays the role to define a phase transition from subsonic to supersonic velocities for polarons in GNRs.

Place, publisher, year, edition, pages
American Chemical Society, 2015
National Category
Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-115322 (URN)10.1021/jz502460g (DOI)000349137400035 ()
Note

Funding Agencies|Swedish Research Council (VR); CNPq; CAPES; FINATEC

Available from: 2015-03-13 Created: 2015-03-13 Last updated: 2019-06-27
Ferreira da Cunha, W., Ribeiro, L. A., Gargano, R. & Magela e Silva, G. (2014). Critical temperature and products of intrachain polaron recombination in conjugated polymers. Physical Chemistry, Chemical Physics - PCCP, 16(32), 17072-17080
Open this publication in new window or tab >>Critical temperature and products of intrachain polaron recombination in conjugated polymers
2014 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 32, p. 17072-17080Article in journal (Refereed) Published
Abstract [en]

The intrachain recombination dynamics between oppositely charged polarons is theoretically investigated through the use of a version of the Su-Schrieffer-Heeger (SSH) model modified to include an external electric field, an extended Hubbard model, Coulomb interactions, and temperature effects in the framework of a nonadiabatic evolution method. Our results indicate notable characteristics concerning the polaron recombination: (1) it is found that there exists a critical temperature regime, below which an exciton is formed directly and (2) a pristine lattice is the resulting product of the recombination process, if the temperature is higher than the critical value. Additionally, it is found that the critical electric field regime plays the role of drastically modifying the system dynamics. These facts suggest that thermal effects in the intrachain recombination of polarons are crucial for the understanding of electroluminescence in optoelectronic devices, such as Polymer Light Emitting Diodes.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2014
National Category
Physical Sciences Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-110271 (URN)10.1039/c4cp02184c (DOI)000340353000022 ()25005593 (PubMedID)
Note

Funding Agencies|Swedish Research Council; Brazilian Research Council CNPq; CAPES; FINATEC

Available from: 2014-09-05 Created: 2014-09-05 Last updated: 2019-06-27Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7468-2946

Search in DiVA

Show all publications