Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages

Jie Yang; Mohammad Afsar Uddin; Yumin Tang; Yulun Wang; Yang Wang; Huimin Su; Rutian Gao; Zhi Kuan Chen; Junfeng Dai; Han Young Woo; Xugang Guo

doi:10.1021/acsami.8b04432

Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages

Jie Yang, Mohammad Afsar Uddin, Yumin Tang, Yulun Wang, Yang Wang, Huimin Su, Rutian Gao, Zhi Kuan Chen, Junfeng Dai, Han Young Woo, Xugang Guo

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

35 Citations (Scopus)

Abstract

We present here a series of wide-band-gap (E_g: >1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as an electron-donating unit and quinoxaline as an electron-Accepting co-unit to attain large open-circuit voltages (V_ocs) and short-circuit currents (J_scs) in nonfullerene organic solar cells (OSCs). Fluorination was utilized to fine-Tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate the polymer backbone planarity through intramolecular noncovalent S···F and/or H···F interactions. Polymers (P2-P4) show an improved molecular packing with a favorable face-on orientation compared to their nonfluorinated analogue (P1), which is critical to charge carrier transport and collection. When mixed with IDIC, a nonfullerene acceptor, P3 with two F atoms, achieves a remarkable V_oc of 1.00 V and a large J_sc of 15.99 mA/cm², simultaneously, yielding a power-conversion efficiency (PCE) of 9.7%. Notably, the 1.00 V V_oc is among the largest values in the IDIC-based OSCs, leading to a small energy loss (E_loss: 0.62 eV) while maintaining a large PCE. The P3:IDIC blend shows an efficient exciton dissociation through hole transfer even under a small energy offset of 0.16 eV. Further fluorination leads to the polymer P4 with increased chain-Twisting and mismatched FMO levels with IDIC, showing the lowest PCE of 2.93%. The results demonstrate that quinoxaline-based copolymers are promising donors for efficient OSCs and the fluorination needs to be fine-Adjusted to optimize the interchain packing and physicochemical properties of polymers. Additionally, the structure-property correlations from this work provide useful insights for developing wide-band-gap polymers with low-lying highest occupied molecular orbitals to minimize E_loss and maximize V_oc in nonfullerene OSCs for efficient power conversion.

Original language	English
Pages (from-to)	23235-23246
Number of pages	12
Journal	ACS Applied Materials and Interfaces
Volume	10
Issue number	27
DOIs	https://doi.org/10.1021/acsami.8b04432
Publication status	Published - 2018 Jul 11

Bibliographical note

Funding Information:
X.G. is grateful to the National Science Foundation of China (21774055), Shenzhen Peacock Plan Project (KQTD20140630110339343), Shenzhen Basic Research Fund (JCYJ20160530185244662), Guangdong Natural Science Foundation (2015A030313900), and South University of Science and Technology of China (FRG-SUSTC1501A-72). M.A.U. and H.Y.W. acknowledge the financial support from the NRF of Korea (2015R1D1A1A09056905, 20100020209) and Korea University Grant.

Publisher Copyright:
Copyright © 2018 American Chemical Society.

Keywords

energy losses
fluorination
nonfullerene organic solar cells
open-circuit voltages
polymer semiconductors

ASJC Scopus subject areas

Materials Science(all)

Access to Document

10.1021/acsami.8b04432

Cite this

@article{a91256c34f71404aa737a77315c4a403,

title = "Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages",

abstract = "We present here a series of wide-band-gap (Eg: >1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as an electron-donating unit and quinoxaline as an electron-Accepting co-unit to attain large open-circuit voltages (Vocs) and short-circuit currents (Jscs) in nonfullerene organic solar cells (OSCs). Fluorination was utilized to fine-Tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate the polymer backbone planarity through intramolecular noncovalent S···F and/or H···F interactions. Polymers (P2-P4) show an improved molecular packing with a favorable face-on orientation compared to their nonfluorinated analogue (P1), which is critical to charge carrier transport and collection. When mixed with IDIC, a nonfullerene acceptor, P3 with two F atoms, achieves a remarkable Voc of 1.00 V and a large Jsc of 15.99 mA/cm2, simultaneously, yielding a power-conversion efficiency (PCE) of 9.7%. Notably, the 1.00 V Voc is among the largest values in the IDIC-based OSCs, leading to a small energy loss (Eloss: 0.62 eV) while maintaining a large PCE. The P3:IDIC blend shows an efficient exciton dissociation through hole transfer even under a small energy offset of 0.16 eV. Further fluorination leads to the polymer P4 with increased chain-Twisting and mismatched FMO levels with IDIC, showing the lowest PCE of 2.93%. The results demonstrate that quinoxaline-based copolymers are promising donors for efficient OSCs and the fluorination needs to be fine-Adjusted to optimize the interchain packing and physicochemical properties of polymers. Additionally, the structure-property correlations from this work provide useful insights for developing wide-band-gap polymers with low-lying highest occupied molecular orbitals to minimize Eloss and maximize Voc in nonfullerene OSCs for efficient power conversion.",

keywords = "energy losses, fluorination, nonfullerene organic solar cells, open-circuit voltages, polymer semiconductors",

author = "Jie Yang and Uddin, {Mohammad Afsar} and Yumin Tang and Yulun Wang and Yang Wang and Huimin Su and Rutian Gao and Chen, {Zhi Kuan} and Junfeng Dai and Woo, {Han Young} and Xugang Guo",

note = "Funding Information: X.G. is grateful to the National Science Foundation of China (21774055), Shenzhen Peacock Plan Project (KQTD20140630110339343), Shenzhen Basic Research Fund (JCYJ20160530185244662), Guangdong Natural Science Foundation (2015A030313900), and South University of Science and Technology of China (FRG-SUSTC1501A-72). M.A.U. and H.Y.W. acknowledge the financial support from the NRF of Korea (2015R1D1A1A09056905, 20100020209) and Korea University Grant. Publisher Copyright: Copyright {\textcopyright} 2018 American Chemical Society.",

year = "2018",

month = jul,

day = "11",

doi = "10.1021/acsami.8b04432",

language = "English",

volume = "10",

pages = "23235--23246",

journal = "ACS Applied Materials and Interfaces",

issn = "1944-8244",

publisher = "American Chemical Society",

number = "27",

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TY - JOUR

T1 - Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages

AU - Yang, Jie

AU - Uddin, Mohammad Afsar

AU - Tang, Yumin

AU - Wang, Yulun

AU - Wang, Yang

AU - Su, Huimin

AU - Gao, Rutian

AU - Chen, Zhi Kuan

AU - Dai, Junfeng

AU - Woo, Han Young

AU - Guo, Xugang

N1 - Funding Information: X.G. is grateful to the National Science Foundation of China (21774055), Shenzhen Peacock Plan Project (KQTD20140630110339343), Shenzhen Basic Research Fund (JCYJ20160530185244662), Guangdong Natural Science Foundation (2015A030313900), and South University of Science and Technology of China (FRG-SUSTC1501A-72). M.A.U. and H.Y.W. acknowledge the financial support from the NRF of Korea (2015R1D1A1A09056905, 20100020209) and Korea University Grant. Publisher Copyright: Copyright © 2018 American Chemical Society.

PY - 2018/7/11

Y1 - 2018/7/11

N2 - We present here a series of wide-band-gap (Eg: >1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as an electron-donating unit and quinoxaline as an electron-Accepting co-unit to attain large open-circuit voltages (Vocs) and short-circuit currents (Jscs) in nonfullerene organic solar cells (OSCs). Fluorination was utilized to fine-Tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate the polymer backbone planarity through intramolecular noncovalent S···F and/or H···F interactions. Polymers (P2-P4) show an improved molecular packing with a favorable face-on orientation compared to their nonfluorinated analogue (P1), which is critical to charge carrier transport and collection. When mixed with IDIC, a nonfullerene acceptor, P3 with two F atoms, achieves a remarkable Voc of 1.00 V and a large Jsc of 15.99 mA/cm2, simultaneously, yielding a power-conversion efficiency (PCE) of 9.7%. Notably, the 1.00 V Voc is among the largest values in the IDIC-based OSCs, leading to a small energy loss (Eloss: 0.62 eV) while maintaining a large PCE. The P3:IDIC blend shows an efficient exciton dissociation through hole transfer even under a small energy offset of 0.16 eV. Further fluorination leads to the polymer P4 with increased chain-Twisting and mismatched FMO levels with IDIC, showing the lowest PCE of 2.93%. The results demonstrate that quinoxaline-based copolymers are promising donors for efficient OSCs and the fluorination needs to be fine-Adjusted to optimize the interchain packing and physicochemical properties of polymers. Additionally, the structure-property correlations from this work provide useful insights for developing wide-band-gap polymers with low-lying highest occupied molecular orbitals to minimize Eloss and maximize Voc in nonfullerene OSCs for efficient power conversion.

AB - We present here a series of wide-band-gap (Eg: >1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as an electron-donating unit and quinoxaline as an electron-Accepting co-unit to attain large open-circuit voltages (Vocs) and short-circuit currents (Jscs) in nonfullerene organic solar cells (OSCs). Fluorination was utilized to fine-Tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate the polymer backbone planarity through intramolecular noncovalent S···F and/or H···F interactions. Polymers (P2-P4) show an improved molecular packing with a favorable face-on orientation compared to their nonfluorinated analogue (P1), which is critical to charge carrier transport and collection. When mixed with IDIC, a nonfullerene acceptor, P3 with two F atoms, achieves a remarkable Voc of 1.00 V and a large Jsc of 15.99 mA/cm2, simultaneously, yielding a power-conversion efficiency (PCE) of 9.7%. Notably, the 1.00 V Voc is among the largest values in the IDIC-based OSCs, leading to a small energy loss (Eloss: 0.62 eV) while maintaining a large PCE. The P3:IDIC blend shows an efficient exciton dissociation through hole transfer even under a small energy offset of 0.16 eV. Further fluorination leads to the polymer P4 with increased chain-Twisting and mismatched FMO levels with IDIC, showing the lowest PCE of 2.93%. The results demonstrate that quinoxaline-based copolymers are promising donors for efficient OSCs and the fluorination needs to be fine-Adjusted to optimize the interchain packing and physicochemical properties of polymers. Additionally, the structure-property correlations from this work provide useful insights for developing wide-band-gap polymers with low-lying highest occupied molecular orbitals to minimize Eloss and maximize Voc in nonfullerene OSCs for efficient power conversion.

KW - energy losses

KW - fluorination

KW - nonfullerene organic solar cells

KW - open-circuit voltages

KW - polymer semiconductors

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SN - 1944-8244

VL - 10

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EP - 23246

JO - ACS Applied Materials and Interfaces

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IS - 27

ER -

Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages

Abstract

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Keywords

ASJC Scopus subject areas

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