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Volumn 112, Issue 2, 2008, Pages 495-506

Phonon-driven exciton dissociation at donor - Acceptor polymer heterojunctions: direct versus bridge-mediated vibronic coupling pathways

Author keywords

[No Author keywords available]

Indexed keywords

COMPUTER SIMULATION; HETEROJUNCTIONS; PARAMETERIZATION; POLYMERS; QUANTUM THEORY; ULTRASHORT PULSES;

EID: 38749105456     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp077270p     Document Type: Article
Times cited : (41)

References (68)
  • 9
    • 33748059662 scopus 로고    scopus 로고
    • Müllen, K, Scherf, U, Eds, Wiley-VCH: New York
    • Organic Light-Emitting Devices; Müllen, K., Scherf, U., Eds.; Wiley-VCH: New York, 2006.
    • (2006) Organic Light-Emitting Devices
  • 27
    • 26444513977 scopus 로고    scopus 로고
    • Domcke, W, Yarkony, D. R, Koppel, H, Eds, World Scientific: New Jersey
    • Koppel, H.; Domcke, W.; Cederbaum, L. S. In Conical Intersections; Domcke, W., Yarkony, D. R., Koppel, H., Eds.; World Scientific: New Jersey, 2004; Vol. 15, p 323.
    • (2004) Conical Intersections , vol.15 , pp. 323
    • Koppel, H.1    Domcke, W.2    Cederbaum, L.S.3
  • 39
    • 84906362344 scopus 로고    scopus 로고
    • Worth, G. A, Beck, M. H, Jäckle, A, Meyer, H. The MCTDH Package, version 8.2; Universität Heidelberg: Heidelberg, Germany, 2000
    • (a) Worth, G. A.; Beck, M. H.; Jäckle, A.; Meyer, H. The MCTDH Package, version 8.2; Universität Heidelberg: Heidelberg, Germany, 2000.
  • 40
    • 84906390869 scopus 로고    scopus 로고
    • Meyer, H.-D. The MCTDH Package, version 8.3; Universität Heidelberg: Heidelberg, Germany, 2002. See
    • (b)Meyer, H.-D. The MCTDH Package, version 8.3; Universität Heidelberg: Heidelberg, Germany, 2002. See http://www.pci.uni-heidelberg.de/tc/ usr/mctdh/.
  • 53
    • 84906405485 scopus 로고    scopus 로고
    • The assumption of the present treatment is thus that the photogenerated exciton is localized at the interface; this assumption is implicit in the oligomer calculations we carried out.31,32 In the actual material, the highly filamented bulk heterojunction structure indeed facilitates an immediate decay since the exciton is likely to reach the interface within its short diffusion length on the order of ∼10 nm;19-20 see Introduction, Experimental observations for related polymer interfaces 64 show that a considerable range of decay time scales can exist, reflecting an ultrafast decay of a subset of excitons, while longer time scales are associated with exciton states which are not localized in the immediate vicinity of the interface. The present study focuses on the former subset of rapidly decaying excitons
    • 64 show that a considerable range of decay time scales can exist, reflecting an ultrafast decay of a subset of excitons, while longer time scales are associated with exciton states which are not localized in the immediate vicinity of the interface. The present study focuses on the former subset of rapidly decaying excitons.
  • 61
    • 84906362345 scopus 로고    scopus 로고
    • The present applications are restricted to a zero temperature setting, that is, the initial bath state is specified as ρ̂B, ψB(0)〉〈ψB(0, with |ψB〈 as the uncorrected bath ground-state wave function. This construction entails that the dissipative effects are determined by a quantum fluctuation dissipation theorem, χ(ω, ℏω coth(ℏω/2kBT)γ(ω),65,-67 taken to the zero temperature limit, coth(ℏω/2kBT) →T=0 1. Here, χ(ω, ∫dt〈ξ(0)〉(0)cos ωt is the power spectrum of the symmetrized correlation function of the fluctuating force, and γ(ω, J(ω)/ω is the damping kernel. As detailed in refs 65-67, all quantities are explicitly determined in terms of the microscopic harmonic oscillator model applied here
    • T=0 1. Here, χ(ω) = ∫dt〈ξ(0)〉(0)cos ωt is the power spectrum of the symmetrized correlation function of the fluctuating force, and γ(ω) = J(ω)/ω is the damping kernel. As detailed in refs 65-67, all quantities are explicitly determined in terms of the microscopic harmonic oscillator model applied here.
  • 63
    • 84906376553 scopus 로고    scopus 로고
    • In fact, by this construction of the external bath, energy relaxation and dephasing effects are more efficient than those generated by the higher orders of the actual HEP hierarchy. As mentioned above, the following order, that is, the second HEP order, which is disregarded here due to the n, 1 truncation, is composed of high-frequency modes; these are off-resonant with respect to the ring-torsional modes and do not produce an efficient energy relaxation; see the discussion in ref 29
    • In fact, by this construction of the external bath, energy relaxation and dephasing effects are more efficient than those generated by the higher orders of the actual HEP hierarchy. As mentioned above, the following order, that is, the second HEP order, which is disregarded here due to the n = 1 truncation, is composed of high-frequency modes; these are off-resonant with respect to the ring-torsional modes and do not produce an efficient energy relaxation; see the discussion in ref 29.
  • 65
    • 84906372175 scopus 로고    scopus 로고
    • Excitation Transport and Charge Separation in an Organic Photovoltaic Material: Watching Excitations Diffuse to Interfaces
    • Preprint
    • Barbour, L. W.; Hegadorn, M.; Arzhantsev, S.; Asbury, J. B. Excitation Transport and Charge Separation in an Organic Photovoltaic Material: Watching Excitations Diffuse to Interfaces; Preprint.
    • Barbour, L.W.1    Hegadorn, M.2    Arzhantsev, S.3    Asbury, J.B.4


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.