Charge Separation in Donor-C60 Complexes with Real-Time Green Functions: The Importance of Nonlocal Correlations

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

We use the nonequilibrium Green function (NEGF) method to perform real-time simulations of the ultrafast electron dynamics of photoexcited donor-C60 complexes modeled by a Pariser-Parr-Pople Hamiltonian. The NEGF results are compared to mean-field Hartree-Fock (HF) calculations to disentangle the role of correlations. Initial benchmarking against numerically highly accurate time-dependent density matrix renormalization group calculations verifies the accuracy of NEGF. We then find that charge-transfer (CT) excitons partially decay into charge separated (CS) states if dynamical nonlocal correlation corrections are included. This CS process occurs in ∼10 fs after photoexcitation. In contrast, the probability of exciton recombination is almost 100% in HF simulations. These results are largely unaffected by nuclear vibrations; the latter become however essential whenever level misalignment hinders the CT process. The robust nature of our findings indicates that ultrafast CS driven by correlation-induced decoherence may occur in many organic nanoscale systems, but it will only be correctly predicted by theoretical treatments that include time-nonlocal correlations.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • University of Rome Tor Vergata
  • Istituto Nazionale di Fisica Nucleare
  • Istituto di Struttura della Materia ISM
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Den kondenserade materiens fysik
  • Nanoteknik

Nyckelord

Originalspråkengelska
Sidor (från-till)785-792
Antal sidor8
TidskriftNano Letters
Volym18
Utgivningsnummer2
StatusPublished - 2018 feb 14
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Emil Vinas Boström, 2018 maj 7, Lund: Lund University, Faculty of Science, Department of Physics. 177 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

Visa alla (1)