Nonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximation

Handle URI:
http://hdl.handle.net/10754/598996
Title:
Nonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximation
Authors:
Yi, Yuanping; Coropceanu, Veaceslav; Brédas, Jean-Luc
Abstract:
There is currently increasing interest in understanding the impact of the nonlocal (Peierls-type) electron-phonon mechanism on charge transport in organic molecular semiconductors. Most estimates of the non-local coupling constants reported in the literature are based on the Γ-point phonon modes. Here, the influence of phonon modes spanning the entire Brillouin zone (phonon dispersion) on the nonlocal electron-phonon couplings is investigated for the pentacene crystal. The phonon modes are obtained by using a supercell approach. The results underline that the overall nonlocal couplings are substantially underestimated by calculations taking sole account of the phonons at the Γ point of the unit cell. The variance of the transfer integrals based on Γ-point normal-mode calculations at room temperature is underestimated in some cases by 40% for herringbone-type dimers and by over 80% for cofacial dimers. Our calculations show that the overall coupling is somewhat larger for holes than for electrons. The results also suggest that the interactions of charge carriers (both electrons and holes) with acoustic and optical phonons are comparable. Therefore, an adequate description of the charge-transport properties in pentacene and similar systems requires that these two electron-phonon coupling mechanisms be treated on the same footing. © 2012 American Institute of Physics.
Citation:
Yi Y, Coropceanu V, Brédas J-L (2012) Nonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximation. J Chem Phys 137: 164303. Available: http://dx.doi.org/10.1063/1.4759040.
Publisher:
AIP Publishing
Journal:
The Journal of Chemical Physics
KAUST Grant Number:
KUS-C1-015-21
Issue Date:
2012
DOI:
10.1063/1.4759040
PubMed ID:
23126706
Type:
Article
ISSN:
0021-9606
Sponsors:
The authors acknowledge many stimulating discussions with Dr. Y. Li. This work has been partially supported by the Office of Naval Research and the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21 made by King Abdullah University of Science and Technology, KAUST). The computational resources have been made partly available via the CRIF Program of the NSF (Award No. CHE-0946869).
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Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorYi, Yuanpingen
dc.contributor.authorCoropceanu, Veaceslaven
dc.contributor.authorBrédas, Jean-Lucen
dc.date.accessioned2016-02-25T13:50:50Zen
dc.date.available2016-02-25T13:50:50Zen
dc.date.issued2012en
dc.identifier.citationYi Y, Coropceanu V, Brédas J-L (2012) Nonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximation. J Chem Phys 137: 164303. Available: http://dx.doi.org/10.1063/1.4759040.en
dc.identifier.issn0021-9606en
dc.identifier.pmid23126706en
dc.identifier.doi10.1063/1.4759040en
dc.identifier.urihttp://hdl.handle.net/10754/598996en
dc.description.abstractThere is currently increasing interest in understanding the impact of the nonlocal (Peierls-type) electron-phonon mechanism on charge transport in organic molecular semiconductors. Most estimates of the non-local coupling constants reported in the literature are based on the Γ-point phonon modes. Here, the influence of phonon modes spanning the entire Brillouin zone (phonon dispersion) on the nonlocal electron-phonon couplings is investigated for the pentacene crystal. The phonon modes are obtained by using a supercell approach. The results underline that the overall nonlocal couplings are substantially underestimated by calculations taking sole account of the phonons at the Γ point of the unit cell. The variance of the transfer integrals based on Γ-point normal-mode calculations at room temperature is underestimated in some cases by 40% for herringbone-type dimers and by over 80% for cofacial dimers. Our calculations show that the overall coupling is somewhat larger for holes than for electrons. The results also suggest that the interactions of charge carriers (both electrons and holes) with acoustic and optical phonons are comparable. Therefore, an adequate description of the charge-transport properties in pentacene and similar systems requires that these two electron-phonon coupling mechanisms be treated on the same footing. © 2012 American Institute of Physics.en
dc.description.sponsorshipThe authors acknowledge many stimulating discussions with Dr. Y. Li. This work has been partially supported by the Office of Naval Research and the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21 made by King Abdullah University of Science and Technology, KAUST). The computational resources have been made partly available via the CRIF Program of the NSF (Award No. CHE-0946869).en
dc.publisherAIP Publishingen
dc.titleNonlocal electron-phonon coupling in the pentacene crystal: Beyond the Γ-point approximationen
dc.typeArticleen
dc.identifier.journalThe Journal of Chemical Physicsen
dc.contributor.institutionGeorgia Institute of Technology, Atlanta, United Statesen
dc.contributor.institutionKing Abdulaziz University, Jeddah, Saudi Arabiaen
kaust.grant.numberKUS-C1-015-21en
kaust.grant.fundedcenterCenter for Advanced Molecular Photovoltaics (CAMP)en

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