Staff Members - Benha University
PEDOTs–PCnBMs polymer–fullereneBHJsolarcells: Quantum mechanicalcalculationsofphotovoltaic and photophysicalproperties
Nano Energy(2012) 1, 608–623 • 2012
Publication Information
Authors
A.S. Shalabin, S.AbdelAal,M.M.Assem
Keywords
Not Available
Journal
Nano Energy(2012) 1, 608–623
Publisher
Not Available
Volume
Not Available
Issue
Not Available
Pages
Not Available
publication.type
International
Paper Link
Not Available
Supplementary Materials
Not Available
Abstract
The bandgaps,geometries,electronicstructures,polarizabilities,hyperpolarizabilities,dipole
moments, UV–visible,IR, 1H and 13C NMRofpoly(3,4-ethylenedioxythiophene)(PEDOT)andits
fluorine derivatives—Cn and [6,6] phenylCn butyric acidmethylesters(PCnBMs) bulk
heterojunction (BHJ)solarcellsareinvestigatedbyusingdensityfunctionaltheory(DFT)and
time-dependant densityfunctionaltheory(TD-DFT)calculations.Weaimtooptimizethe
performance ofthesesolarcellsbyalteringthefrontierorbitalenergygapsofpolymersand
fullerenes. Thiswasdonebyfunctionalizingthepolymersbackboneswithelectronwithdrawing
fluorines step-bystep,andbyaddingphenylbutyricacidmethylestertothebuckminsterC60
and C70 fullerenes. Thetheoreticaldatawerecomparedwiththeavailableexperimentaldata.
Based onthestrategyofreducingthebandgaps,thetrifluoroderivativeofPEDOT–buckminster
C70 fullerene blend(outof24blends)wasfoundtobethebestcandidateforpowerconversion
efficiency (PCE).Theadditionoffluorineatomstothepolymerbackboneiseffectivein
lowering bothHOMOsandLUMOs.Conformationalanalysisconfirmsthatthecoplanarproper-
tyof thiophenepolymersarenotdestroyedbytheincorporationoffluorineatoms.Whilestrong
localization ofHOMOsoccursonthePEDOTdonorsubunits,strongdelocaliztionofLUMOs
occurs onthebridgesbetweenthesubunits,provingtheflowoftheelectrondensityalongthe
polymer backbone.Thepolarizabilityterm bxxx and dipolemoment mx increase withincreasing
the powerconversionefficiency.Theabsorptionbandthatcorrespondstothemaximum
coefficient ofthePEDOTinvacuumismarginallyshiftedundertheeffectofincorporating
fluorines. VibrationalanalysisshowsthatfunctionalizingPEDOTleadstoamoreconjugated
polymer backboneandenhancesthechargetransfertoanacceptor.Thepowerconversion
efficiency ofthesolarcellincreaseswithincreasingthechemicalshiftsoftheconstituentC,H,
and Oatoms.
moments, UV–visible,IR, 1H and 13C NMRofpoly(3,4-ethylenedioxythiophene)(PEDOT)andits
fluorine derivatives—Cn and [6,6] phenylCn butyric acidmethylesters(PCnBMs) bulk
heterojunction (BHJ)solarcellsareinvestigatedbyusingdensityfunctionaltheory(DFT)and
time-dependant densityfunctionaltheory(TD-DFT)calculations.Weaimtooptimizethe
performance ofthesesolarcellsbyalteringthefrontierorbitalenergygapsofpolymersand
fullerenes. Thiswasdonebyfunctionalizingthepolymersbackboneswithelectronwithdrawing
fluorines step-bystep,andbyaddingphenylbutyricacidmethylestertothebuckminsterC60
and C70 fullerenes. Thetheoreticaldatawerecomparedwiththeavailableexperimentaldata.
Based onthestrategyofreducingthebandgaps,thetrifluoroderivativeofPEDOT–buckminster
C70 fullerene blend(outof24blends)wasfoundtobethebestcandidateforpowerconversion
efficiency (PCE).Theadditionoffluorineatomstothepolymerbackboneiseffectivein
lowering bothHOMOsandLUMOs.Conformationalanalysisconfirmsthatthecoplanarproper-
tyof thiophenepolymersarenotdestroyedbytheincorporationoffluorineatoms.Whilestrong
localization ofHOMOsoccursonthePEDOTdonorsubunits,strongdelocaliztionofLUMOs
occurs onthebridgesbetweenthesubunits,provingtheflowoftheelectrondensityalongthe
polymer backbone.Thepolarizabilityterm bxxx and dipolemoment mx increase withincreasing
the powerconversionefficiency.Theabsorptionbandthatcorrespondstothemaximum
coefficient ofthePEDOTinvacuumismarginallyshiftedundertheeffectofincorporating
fluorines. VibrationalanalysisshowsthatfunctionalizingPEDOTleadstoamoreconjugated
polymer backboneandenhancesthechargetransfertoanacceptor.Thepowerconversion
efficiency ofthesolarcellincreaseswithincreasingthechemicalshiftsoftheconstituentC,H,
and Oatoms.