Energetics of charges in organic semiconductors and at organic donor-acceptor interfaces
dc.contributor.author
dc.date.accessioned
2015-11-09T10:47:57Z
dc.date.available
2015-11-09T10:47:57Z
dc.date.issued
2014-05-07
dc.identifier.issn
2050-7534
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dc.description.abstract
We calculated the energy landscape of charged molecules that is determined by electrostatic and induction interaction using the fully polarizable force field DRF90 in the bulk and at interfaces of the electron accepting material C60, and two exemplary electron donating materials pentacene and phthalocyanine. In particular, we compared the energy of a non-interacting electron-hole pair (NI-EH) without mutual electrostatic interactions to the energy of a Coulomb-bound interfacial charge-transfer state (CT). Our calculations show that due to electrostatic interactions with the environment a NI-EH state is destabilized on the phthalocyanine-C60 interface, whereas it is stabilized on the interface between pentacene and C60, even without the interaction with the counter charge. Upon adding the mutual electrostatic interaction between the opposite charges the electrostatic term overall stabilizes the CT state in both systems. This stabilization is not compensated by the reduced induction term. The resulting binding energy of the CT state amounts to several tenths of an eV, which contradicts the evidence of working solar cells based on these systems. The overestimated CT state binding energy for charges localized on a single molecule suggests that charge delocalization over multiple molecules might play an important role. Nevertheless, our results indicate clear opportunities to engineer electrostatic interactions at the interface that might lead to destabilization of NI-EH and hence to a lower binding energy of CT
dc.description.sponsorship
This work was supported by the Netherlands Organization for Scientific Research (NWO) through an VIDI grant to FCG and by the European Research Council (ERC) in the form of ERC Starting Grant to FCG. The following organizations are thanked for financial support: the Ministerio de Ciencia e Innovacion (MICINN, project number CTQ2011-25086/ BQU) and the DIUE of the Generalitat de Catalunya (project number 2009SGR528, and Xarxa de Referencia en Quimica Teorica i Computacional)
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
Royal Society of Chemistry (RSC)
dc.relation
info:eu-repo/grantAgreement/MICINN//CTQ2011-25086/ES/MODELIZACION MULTIESCALAR EN (BIO)QUIMICA/
AGAUR/2009-2014/2009 SGR-528
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Reproducció digital del document publicat a: http://dx.doi.org/10.1039/c3tc32475c
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© Journal of Materials Chemistry C, 2014, vol. 2, núm. 17, p. 3467-3475
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Articles publicats (D-Q)
dc.rights
Attribution 3.0 Spain
dc.rights.uri
dc.subject
dc.title
Energetics of charges in organic semiconductors and at organic donor-acceptor interfaces
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.embargo.terms
Cap
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
020644
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dc.relation.ProjectAcronym