Interfacial electronic structure of Cl 6 SubPc non-fullerene acceptors in organic photovoltaics using soft X-ray spectroscopies

Hyunbok Lee, Sun Woo Ahn, Sim Hee Ryu, Bo Kyung Ryu, Myeung Hee Lee, Sangwan Cho, Kevin E. Smith, Tim S. Jones

Research output: Contribution to journalArticle

Abstract

In organic photovoltaics (OPVs), determining the energy-level alignment of a donor and an acceptor is particularly important since the interfacial energy gap between the highest occupied molecular orbital (HOMO) level of a donor and the lowest unoccupied molecular orbital (LUMO) level of an acceptor (EDHOMO-EALUMO) gives the theoretical maximum value of the open-circuit voltage (V OC ). To increase the EDHOMO-EALUMO, non-fullerene acceptors, which have a lower electron affinity (EA) than C 60 , are receiving increasing attention. In this study, we investigated the energy-level alignment at the interface of a boron chloride subphthalocyanine (SubPc) donor and a halogenated SubPc (Cl 6 SubPc) acceptor using soft X-ray spectroscopy techniques. The estimated EDHOMO-EALUMO of Cl 6 SubPc/SubPc was 1.95 eV, which was significantly higher than that of 1.51 eV found at the interface of C 60 /SubPc. This increased EDHOMO-EALUMO was the origin of the enhanced V OC in OPVs. Additionally, we studied the molecular orientation of Cl 6 SubPc using angle-dependent X-ray absorption spectroscopy. The highly disordered Cl 6 SubPc molecules result in low carrier mobility, which contributes to the lower short-circuit current density of the Cl 6 SubPc acceptor OPVs than the C 60 acceptor OPVs.

Original languageEnglish
Pages (from-to)31628-31633
Number of pages6
JournalPhysical Chemistry Chemical Physics
Volume19
Issue number47
DOIs
Publication statusPublished - 2017 Jan 1

Fingerprint

Molecular orbitals
Open circuit voltage
X ray spectroscopy
open circuit voltage
Electron energy levels
Electronic structure
boron chlorides
molecular orbitals
energy levels
alignment
electronic structure
Electron affinity
X ray absorption spectroscopy
Boron
interfacial energy
Molecular orientation
Carrier mobility
short circuit currents
carrier mobility
electron affinity

All Science Journal Classification (ASJC) codes

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

Cite this

Lee, Hyunbok ; Ahn, Sun Woo ; Ryu, Sim Hee ; Ryu, Bo Kyung ; Lee, Myeung Hee ; Cho, Sangwan ; Smith, Kevin E. ; Jones, Tim S. / Interfacial electronic structure of Cl 6 SubPc non-fullerene acceptors in organic photovoltaics using soft X-ray spectroscopies In: Physical Chemistry Chemical Physics. 2017 ; Vol. 19, No. 47. pp. 31628-31633.
@article{9b48ce0a67614917a00866fffffb8dcc,
title = "Interfacial electronic structure of Cl 6 SubPc non-fullerene acceptors in organic photovoltaics using soft X-ray spectroscopies",
abstract = "In organic photovoltaics (OPVs), determining the energy-level alignment of a donor and an acceptor is particularly important since the interfacial energy gap between the highest occupied molecular orbital (HOMO) level of a donor and the lowest unoccupied molecular orbital (LUMO) level of an acceptor (EDHOMO-EALUMO) gives the theoretical maximum value of the open-circuit voltage (V OC ). To increase the EDHOMO-EALUMO, non-fullerene acceptors, which have a lower electron affinity (EA) than C 60 , are receiving increasing attention. In this study, we investigated the energy-level alignment at the interface of a boron chloride subphthalocyanine (SubPc) donor and a halogenated SubPc (Cl 6 SubPc) acceptor using soft X-ray spectroscopy techniques. The estimated EDHOMO-EALUMO of Cl 6 SubPc/SubPc was 1.95 eV, which was significantly higher than that of 1.51 eV found at the interface of C 60 /SubPc. This increased EDHOMO-EALUMO was the origin of the enhanced V OC in OPVs. Additionally, we studied the molecular orientation of Cl 6 SubPc using angle-dependent X-ray absorption spectroscopy. The highly disordered Cl 6 SubPc molecules result in low carrier mobility, which contributes to the lower short-circuit current density of the Cl 6 SubPc acceptor OPVs than the C 60 acceptor OPVs.",
author = "Hyunbok Lee and Ahn, {Sun Woo} and Ryu, {Sim Hee} and Ryu, {Bo Kyung} and Lee, {Myeung Hee} and Sangwan Cho and Smith, {Kevin E.} and Jones, {Tim S.}",
year = "2017",
month = "1",
day = "1",
doi = "10.1039/c7cp04876a",
language = "English",
volume = "19",
pages = "31628--31633",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "47",

}

Interfacial electronic structure of Cl 6 SubPc non-fullerene acceptors in organic photovoltaics using soft X-ray spectroscopies . / Lee, Hyunbok; Ahn, Sun Woo; Ryu, Sim Hee; Ryu, Bo Kyung; Lee, Myeung Hee; Cho, Sangwan; Smith, Kevin E.; Jones, Tim S.

In: Physical Chemistry Chemical Physics, Vol. 19, No. 47, 01.01.2017, p. 31628-31633.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Interfacial electronic structure of Cl 6 SubPc non-fullerene acceptors in organic photovoltaics using soft X-ray spectroscopies

AU - Lee, Hyunbok

AU - Ahn, Sun Woo

AU - Ryu, Sim Hee

AU - Ryu, Bo Kyung

AU - Lee, Myeung Hee

AU - Cho, Sangwan

AU - Smith, Kevin E.

AU - Jones, Tim S.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - In organic photovoltaics (OPVs), determining the energy-level alignment of a donor and an acceptor is particularly important since the interfacial energy gap between the highest occupied molecular orbital (HOMO) level of a donor and the lowest unoccupied molecular orbital (LUMO) level of an acceptor (EDHOMO-EALUMO) gives the theoretical maximum value of the open-circuit voltage (V OC ). To increase the EDHOMO-EALUMO, non-fullerene acceptors, which have a lower electron affinity (EA) than C 60 , are receiving increasing attention. In this study, we investigated the energy-level alignment at the interface of a boron chloride subphthalocyanine (SubPc) donor and a halogenated SubPc (Cl 6 SubPc) acceptor using soft X-ray spectroscopy techniques. The estimated EDHOMO-EALUMO of Cl 6 SubPc/SubPc was 1.95 eV, which was significantly higher than that of 1.51 eV found at the interface of C 60 /SubPc. This increased EDHOMO-EALUMO was the origin of the enhanced V OC in OPVs. Additionally, we studied the molecular orientation of Cl 6 SubPc using angle-dependent X-ray absorption spectroscopy. The highly disordered Cl 6 SubPc molecules result in low carrier mobility, which contributes to the lower short-circuit current density of the Cl 6 SubPc acceptor OPVs than the C 60 acceptor OPVs.

AB - In organic photovoltaics (OPVs), determining the energy-level alignment of a donor and an acceptor is particularly important since the interfacial energy gap between the highest occupied molecular orbital (HOMO) level of a donor and the lowest unoccupied molecular orbital (LUMO) level of an acceptor (EDHOMO-EALUMO) gives the theoretical maximum value of the open-circuit voltage (V OC ). To increase the EDHOMO-EALUMO, non-fullerene acceptors, which have a lower electron affinity (EA) than C 60 , are receiving increasing attention. In this study, we investigated the energy-level alignment at the interface of a boron chloride subphthalocyanine (SubPc) donor and a halogenated SubPc (Cl 6 SubPc) acceptor using soft X-ray spectroscopy techniques. The estimated EDHOMO-EALUMO of Cl 6 SubPc/SubPc was 1.95 eV, which was significantly higher than that of 1.51 eV found at the interface of C 60 /SubPc. This increased EDHOMO-EALUMO was the origin of the enhanced V OC in OPVs. Additionally, we studied the molecular orientation of Cl 6 SubPc using angle-dependent X-ray absorption spectroscopy. The highly disordered Cl 6 SubPc molecules result in low carrier mobility, which contributes to the lower short-circuit current density of the Cl 6 SubPc acceptor OPVs than the C 60 acceptor OPVs.

UR - http://www.scopus.com/inward/record.url?scp=85038436179&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85038436179&partnerID=8YFLogxK

U2 - 10.1039/c7cp04876a

DO - 10.1039/c7cp04876a

M3 - Article

VL - 19

SP - 31628

EP - 31633

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 47

ER -