Yield of exciton dissociation in a donor-acceptor photovoltaic junction

Guangqi Li, Abraham Nitzan, Mark A Ratner

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

A simple model is constructed to describe dissociation of charge transfer excitons in bulk heterojunction solar cells, and its dependence on the physical parameters of the system. In bulk heterojunction organic photovoltaics (OPVs), exciton dissociation occurs almost exclusively at the interface between the donor and acceptor, following one-electron initial excitation from the HOMO to the LUMO levels of the donor, and charge transfer to the acceptor to make a charge-transfer exciton. After exciton breakup, and neglecting the trapping of individual carriers, the electron may undergo two processes for decay: one process involves the electron and/or hole leaving the interface, and migrating to the electrode. This is treated here as the electron moving on a set of acceptor sites. The second loss process is radiationless decay following recombination of the acceptor electron with the donor cation; this is treated by adding a relaxation term. These two processes compete with one another. We model both the exciton breakup and the subsequent electron motion. Results depend on tunneling amplitude, energetics, disorder, Coulomb barriers, and energy level matchups, particularly the so-called LUMO-LUMO offset.

Original languageEnglish
Pages (from-to)14270-14276
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume14
Issue number41
DOIs
Publication statusPublished - Nov 7 2012

Fingerprint

excitons
dissociation
Electrons
Charge transfer
electrons
charge transfer
Heterojunctions
heterojunctions
decay
Electron energy levels
LDS 751
Cations
Solar cells
solar cells
energy levels
trapping
disorders
cations
Electrodes
electrodes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Physics and Astronomy(all)

Cite this

Yield of exciton dissociation in a donor-acceptor photovoltaic junction. / Li, Guangqi; Nitzan, Abraham; Ratner, Mark A.

In: Physical Chemistry Chemical Physics, Vol. 14, No. 41, 07.11.2012, p. 14270-14276.

Research output: Contribution to journalArticle

@article{dada696cd0e7408eb7bea064770994c0,
title = "Yield of exciton dissociation in a donor-acceptor photovoltaic junction",
abstract = "A simple model is constructed to describe dissociation of charge transfer excitons in bulk heterojunction solar cells, and its dependence on the physical parameters of the system. In bulk heterojunction organic photovoltaics (OPVs), exciton dissociation occurs almost exclusively at the interface between the donor and acceptor, following one-electron initial excitation from the HOMO to the LUMO levels of the donor, and charge transfer to the acceptor to make a charge-transfer exciton. After exciton breakup, and neglecting the trapping of individual carriers, the electron may undergo two processes for decay: one process involves the electron and/or hole leaving the interface, and migrating to the electrode. This is treated here as the electron moving on a set of acceptor sites. The second loss process is radiationless decay following recombination of the acceptor electron with the donor cation; this is treated by adding a relaxation term. These two processes compete with one another. We model both the exciton breakup and the subsequent electron motion. Results depend on tunneling amplitude, energetics, disorder, Coulomb barriers, and energy level matchups, particularly the so-called LUMO-LUMO offset.",
author = "Guangqi Li and Abraham Nitzan and Ratner, {Mark A}",
year = "2012",
month = "11",
day = "7",
doi = "10.1039/c2cp41532a",
language = "English",
volume = "14",
pages = "14270--14276",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "41",

}

TY - JOUR

T1 - Yield of exciton dissociation in a donor-acceptor photovoltaic junction

AU - Li, Guangqi

AU - Nitzan, Abraham

AU - Ratner, Mark A

PY - 2012/11/7

Y1 - 2012/11/7

N2 - A simple model is constructed to describe dissociation of charge transfer excitons in bulk heterojunction solar cells, and its dependence on the physical parameters of the system. In bulk heterojunction organic photovoltaics (OPVs), exciton dissociation occurs almost exclusively at the interface between the donor and acceptor, following one-electron initial excitation from the HOMO to the LUMO levels of the donor, and charge transfer to the acceptor to make a charge-transfer exciton. After exciton breakup, and neglecting the trapping of individual carriers, the electron may undergo two processes for decay: one process involves the electron and/or hole leaving the interface, and migrating to the electrode. This is treated here as the electron moving on a set of acceptor sites. The second loss process is radiationless decay following recombination of the acceptor electron with the donor cation; this is treated by adding a relaxation term. These two processes compete with one another. We model both the exciton breakup and the subsequent electron motion. Results depend on tunneling amplitude, energetics, disorder, Coulomb barriers, and energy level matchups, particularly the so-called LUMO-LUMO offset.

AB - A simple model is constructed to describe dissociation of charge transfer excitons in bulk heterojunction solar cells, and its dependence on the physical parameters of the system. In bulk heterojunction organic photovoltaics (OPVs), exciton dissociation occurs almost exclusively at the interface between the donor and acceptor, following one-electron initial excitation from the HOMO to the LUMO levels of the donor, and charge transfer to the acceptor to make a charge-transfer exciton. After exciton breakup, and neglecting the trapping of individual carriers, the electron may undergo two processes for decay: one process involves the electron and/or hole leaving the interface, and migrating to the electrode. This is treated here as the electron moving on a set of acceptor sites. The second loss process is radiationless decay following recombination of the acceptor electron with the donor cation; this is treated by adding a relaxation term. These two processes compete with one another. We model both the exciton breakup and the subsequent electron motion. Results depend on tunneling amplitude, energetics, disorder, Coulomb barriers, and energy level matchups, particularly the so-called LUMO-LUMO offset.

UR - http://www.scopus.com/inward/record.url?scp=84867482241&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84867482241&partnerID=8YFLogxK

U2 - 10.1039/c2cp41532a

DO - 10.1039/c2cp41532a

M3 - Article

C2 - 22955347

AN - SCOPUS:84867482241

VL - 14

SP - 14270

EP - 14276

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 41

ER -