Controlling Energy Levels and Blend Morphology for All-Polymer Solar Cells via Fluorination of a Naphthalene Diimide-Based Copolymer Acceptor

Mohammad Afsar Uddin; Youngkwon Kim; Robert Younts; Wonho Lee; Bhoj Gautam; Joonhyeong Choi; Cheng Wang; Kenan Gundogdu; Bumjoon J. Kim; Han Young Woo

doi:10.1021/acs.macromol.6b01414

Controlling Energy Levels and Blend Morphology for All-Polymer Solar Cells via Fluorination of a Naphthalene Diimide-Based Copolymer Acceptor

Mohammad Afsar Uddin, Youngkwon Kim, Robert Younts, Wonho Lee, Bhoj Gautam, Joonhyeong Choi, Cheng Wang, Kenan Gundogdu, Bumjoon J. Kim, Han Young Woo

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Abstract

We investigate the photovoltaic properties and charge dynamics of all polymer solar cells (all-PSCs) based on poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(2,2′-bithiophene)] (P(NDI2OD-T2)) and its fluorinated analogue, poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(3,3′-difluoro-2,2′-bithiophene)] (P(NDI2OD-T2F)), as the acceptor polymer and poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione] (PBDTTTPD) as the donor polymer. The PBDTTTPD:P(NDI2OD-T2)-based device has a high open-circuit voltage (V_OC) of 1.03 V but suffers from low power conversion efficiency (PCE) of 2.02% with a short-circuit current density (J_SC) and fill factor (FF) of 4.45 mA cm^-2 and 0.44, respectively. In a stark contrast, the PCE of PBDTTTPD:P(NDI2OD-T2F)-based PSC dramatically increases to 6.09% (V_OC = 1.00 V, J_SC = 11.68 mA cm^-2, and FF = 0.52). These results are attributed to the fluorination, which removes the energetic barrier for hole transfer and promotes the formation of the donor/acceptor blend morphology with suppressed phase separation and enhanced intermixed phases. The detailed charge dynamics examined by femtosecond transient absorption spectroscopy suggests the significantly increased hole transfer efficiency and larger populations of long-lived polarons for PBDTTTPD:P(NDI2OD-T2F).

Original language	English
Pages (from-to)	6374-6383
Number of pages	10
Journal	Macromolecules
Volume	49
Issue number	17
DOIs	https://doi.org/10.1021/acs.macromol.6b01414
Publication status	Published - 2016 Sept 13

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation (NRF) of Korea (2015R1A2A1A15055605, 2012M3A6A7055540). This work was also supported by the New and Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), Korea (No. 20133030011330). This work was also supported by Office of Naval Research (ONR) grant N000141310526 (B.R.G., R.Y., and K.G).

Publisher Copyright:
© 2016 American Chemical Society.

Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

ASJC Scopus subject areas

Organic Chemistry
Polymers and Plastics
Inorganic Chemistry
Materials Chemistry

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10.1021/acs.macromol.6b01414

Cite this

@article{d2ce95193803435498ca86d8f9519686,

title = "Controlling Energy Levels and Blend Morphology for All-Polymer Solar Cells via Fluorination of a Naphthalene Diimide-Based Copolymer Acceptor",

abstract = "We investigate the photovoltaic properties and charge dynamics of all polymer solar cells (all-PSCs) based on poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(2,2′-bithiophene)] (P(NDI2OD-T2)) and its fluorinated analogue, poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(3,3′-difluoro-2,2′-bithiophene)] (P(NDI2OD-T2F)), as the acceptor polymer and poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione] (PBDTTTPD) as the donor polymer. The PBDTTTPD:P(NDI2OD-T2)-based device has a high open-circuit voltage (VOC) of 1.03 V but suffers from low power conversion efficiency (PCE) of 2.02% with a short-circuit current density (JSC) and fill factor (FF) of 4.45 mA cm-2 and 0.44, respectively. In a stark contrast, the PCE of PBDTTTPD:P(NDI2OD-T2F)-based PSC dramatically increases to 6.09% (VOC = 1.00 V, JSC = 11.68 mA cm-2, and FF = 0.52). These results are attributed to the fluorination, which removes the energetic barrier for hole transfer and promotes the formation of the donor/acceptor blend morphology with suppressed phase separation and enhanced intermixed phases. The detailed charge dynamics examined by femtosecond transient absorption spectroscopy suggests the significantly increased hole transfer efficiency and larger populations of long-lived polarons for PBDTTTPD:P(NDI2OD-T2F).",

author = "Uddin, {Mohammad Afsar} and Youngkwon Kim and Robert Younts and Wonho Lee and Bhoj Gautam and Joonhyeong Choi and Cheng Wang and Kenan Gundogdu and Kim, {Bumjoon J.} and Woo, {Han Young}",

note = "Funding Information: This work was supported by the National Research Foundation (NRF) of Korea (2015R1A2A1A15055605, 2012M3A6A7055540). This work was also supported by the New and Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), Korea (No. 20133030011330). This work was also supported by Office of Naval Research (ONR) grant N000141310526 (B.R.G., R.Y., and K.G). Publisher Copyright: {\textcopyright} 2016 American Chemical Society. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.",

year = "2016",

month = sep,

day = "13",

doi = "10.1021/acs.macromol.6b01414",

language = "English",

volume = "49",

pages = "6374--6383",

journal = "Macromolecules",

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publisher = "American Chemical Society",

number = "17",

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T1 - Controlling Energy Levels and Blend Morphology for All-Polymer Solar Cells via Fluorination of a Naphthalene Diimide-Based Copolymer Acceptor

AU - Uddin, Mohammad Afsar

AU - Kim, Youngkwon

AU - Younts, Robert

AU - Lee, Wonho

AU - Gautam, Bhoj

AU - Choi, Joonhyeong

AU - Wang, Cheng

AU - Gundogdu, Kenan

AU - Kim, Bumjoon J.

AU - Woo, Han Young

N1 - Funding Information: This work was supported by the National Research Foundation (NRF) of Korea (2015R1A2A1A15055605, 2012M3A6A7055540). This work was also supported by the New and Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), Korea (No. 20133030011330). This work was also supported by Office of Naval Research (ONR) grant N000141310526 (B.R.G., R.Y., and K.G). Publisher Copyright: © 2016 American Chemical Society. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2016/9/13

Y1 - 2016/9/13

N2 - We investigate the photovoltaic properties and charge dynamics of all polymer solar cells (all-PSCs) based on poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(2,2′-bithiophene)] (P(NDI2OD-T2)) and its fluorinated analogue, poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(3,3′-difluoro-2,2′-bithiophene)] (P(NDI2OD-T2F)), as the acceptor polymer and poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione] (PBDTTTPD) as the donor polymer. The PBDTTTPD:P(NDI2OD-T2)-based device has a high open-circuit voltage (VOC) of 1.03 V but suffers from low power conversion efficiency (PCE) of 2.02% with a short-circuit current density (JSC) and fill factor (FF) of 4.45 mA cm-2 and 0.44, respectively. In a stark contrast, the PCE of PBDTTTPD:P(NDI2OD-T2F)-based PSC dramatically increases to 6.09% (VOC = 1.00 V, JSC = 11.68 mA cm-2, and FF = 0.52). These results are attributed to the fluorination, which removes the energetic barrier for hole transfer and promotes the formation of the donor/acceptor blend morphology with suppressed phase separation and enhanced intermixed phases. The detailed charge dynamics examined by femtosecond transient absorption spectroscopy suggests the significantly increased hole transfer efficiency and larger populations of long-lived polarons for PBDTTTPD:P(NDI2OD-T2F).

AB - We investigate the photovoltaic properties and charge dynamics of all polymer solar cells (all-PSCs) based on poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(2,2′-bithiophene)] (P(NDI2OD-T2)) and its fluorinated analogue, poly[(N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,5′-(3,3′-difluoro-2,2′-bithiophene)] (P(NDI2OD-T2F)), as the acceptor polymer and poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione] (PBDTTTPD) as the donor polymer. The PBDTTTPD:P(NDI2OD-T2)-based device has a high open-circuit voltage (VOC) of 1.03 V but suffers from low power conversion efficiency (PCE) of 2.02% with a short-circuit current density (JSC) and fill factor (FF) of 4.45 mA cm-2 and 0.44, respectively. In a stark contrast, the PCE of PBDTTTPD:P(NDI2OD-T2F)-based PSC dramatically increases to 6.09% (VOC = 1.00 V, JSC = 11.68 mA cm-2, and FF = 0.52). These results are attributed to the fluorination, which removes the energetic barrier for hole transfer and promotes the formation of the donor/acceptor blend morphology with suppressed phase separation and enhanced intermixed phases. The detailed charge dynamics examined by femtosecond transient absorption spectroscopy suggests the significantly increased hole transfer efficiency and larger populations of long-lived polarons for PBDTTTPD:P(NDI2OD-T2F).

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U2 - 10.1021/acs.macromol.6b01414

DO - 10.1021/acs.macromol.6b01414

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VL - 49

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JO - Macromolecules

JF - Macromolecules

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ER -

Controlling Energy Levels and Blend Morphology for All-Polymer Solar Cells via Fluorination of a Naphthalene Diimide-Based Copolymer Acceptor

Abstract

Bibliographical note

ASJC Scopus subject areas

UN SDGs

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