6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells

Radhakrishna Ratha; Ashish Singh; Mohammad Adil Afroz; Ritesh Kant Gupta; Martin Baumgarten; Klaus Müllen; Parameswar Krishnan Iyer

doi:10.1016/j.synthmet.2019.04.013

6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells

Radhakrishna Ratha
, Ashish Singh
, Mohammad Adil Afroz
, Ritesh Kant Gupta
, Martin Baumgarten
, Klaus Müllen
, Parameswar Krishnan Iyer

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

12 Scopus citations

Abstract

This work emphasizes on the synthesis of two new acceptor units for donor (D)-acceptor (A)-based polymers used in photovoltaic devices, namely NT-Th and Th-NT-Th. Both the NT-based acceptors have been designed using 5,6-positions of benzothiadiazole (BT) and synthesized by Wittig coupling reaction. Newly synthesized acceptor units distinguishes itself from existing literature of naphtho[2,3-c][1,2,5]thiadiazole (NT) acceptor in having additional two Thiophene (Th) units attached at 6,7 position of NT, imparting into it a unique 2-dimensional (2D) type of conjugated structure. Alternate D-A co-polymer of new NT-based acceptors with commonly used BDT donor was synthesized via Stille coupling, resulting in new conjugated polymers (CPs) namely P(BDT-NTTh) and P(BDT-ThNTTh). Both the CPs were characterized by GPC, UV–vis, ¹H-NMR, ¹³C-NMR, TGA and CV. Dihedral angle for optimized geometry and ICT of newly synthesized NT-based polymers have also been investigated using DFT. Theoretical calculations suggest that incorporating two Th-units, separates the donor and acceptor as in case of P(BDT-ThNTTh) leading to lowering of dihedral angle, with maximum value of 42.9˚ resulting in more planar geometry. PSC performance of synthesized CPs have been examined by fabricating BHJ solar cells with configuration ITO/PEDOT:PSS/Polymer-PC₇₁BM/LiF/Al, which resulted in a PCE of 0.34% and 1.31% with P(BDT-NTTh) and P(BDT-ThNTTh) respectively. Hole-mobility for blend of P(BDT-NTTh) and P(BDT-ThNTTh) with PC₇₁BM were calculated using SCLC (space charge limited current) method by fabricating hole only devices of configuration ITO/PEDOT:PSS/Polymer-PC₇₁BM/Cu and mobility of 2.2 × 10⁻⁶ and 1.5 × 10^-5 cm² V^-1 s^-1 were established respectively. Morphology of active layer of fabricated PSC has been studied with atomic force microscopy (AFM) and is correlated with their performances.

Original language	English
Pages (from-to)	113-121
Number of pages	9
Journal	Synthetic Metals
Volume	252
DOIs	https://doi.org/10.1016/j.synthmet.2019.04.013
State	Published - 1 Jun 2019
Externally published	Yes

Keywords

2D polymer
Dihedral angle
Donor-acceptor conjugated polymer
Napthothiadiazole (NT)
Polymer solar cell (PSC)

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.synthmet.2019.04.013

Cite this

Ratha, R., Singh, A., Afroz, M. A., Gupta, R. K., Baumgarten, M., Müllen, K., & Iyer, P. K. (2019). 6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells. Synthetic Metals, 252, 113-121. https://doi.org/10.1016/j.synthmet.2019.04.013

@article{09344e00e2af4a43a8869296ca033b0e,

title = "6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells",

abstract = "This work emphasizes on the synthesis of two new acceptor units for donor (D)-acceptor (A)-based polymers used in photovoltaic devices, namely NT-Th and Th-NT-Th. Both the NT-based acceptors have been designed using 5,6-positions of benzothiadiazole (BT) and synthesized by Wittig coupling reaction. Newly synthesized acceptor units distinguishes itself from existing literature of naphtho[2,3-c][1,2,5]thiadiazole (NT) acceptor in having additional two Thiophene (Th) units attached at 6,7 position of NT, imparting into it a unique 2-dimensional (2D) type of conjugated structure. Alternate D-A co-polymer of new NT-based acceptors with commonly used BDT donor was synthesized via Stille coupling, resulting in new conjugated polymers (CPs) namely P(BDT-NTTh) and P(BDT-ThNTTh). Both the CPs were characterized by GPC, UV–vis, 1H-NMR, 13C-NMR, TGA and CV. Dihedral angle for optimized geometry and ICT of newly synthesized NT-based polymers have also been investigated using DFT. Theoretical calculations suggest that incorporating two Th-units, separates the donor and acceptor as in case of P(BDT-ThNTTh) leading to lowering of dihedral angle, with maximum value of 42.9˚ resulting in more planar geometry. PSC performance of synthesized CPs have been examined by fabricating BHJ solar cells with configuration ITO/PEDOT:PSS/Polymer-PC71BM/LiF/Al, which resulted in a PCE of 0.34\% and 1.31\% with P(BDT-NTTh) and P(BDT-ThNTTh) respectively. Hole-mobility for blend of P(BDT-NTTh) and P(BDT-ThNTTh) with PC71BM were calculated using SCLC (space charge limited current) method by fabricating hole only devices of configuration ITO/PEDOT:PSS/Polymer-PC71BM/Cu and mobility of 2.2 × 10−6 and 1.5 × 10-5 cm2 V-1 s-1 were established respectively. Morphology of active layer of fabricated PSC has been studied with atomic force microscopy (AFM) and is correlated with their performances.",

keywords = "2D polymer, Dihedral angle, Donor-acceptor conjugated polymer, Napthothiadiazole (NT), Polymer solar cell (PSC)",

author = "Radhakrishna Ratha and Ashish Singh and Afroz, \{Mohammad Adil\} and Gupta, \{Ritesh Kant\} and Martin Baumgarten and Klaus M{\"u}llen and Iyer, \{Parameswar Krishnan\}",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = jun,

day = "1",

doi = "10.1016/j.synthmet.2019.04.013",

language = "English",

volume = "252",

pages = "113--121",

journal = "Synthetic Metals",

issn = "0379-6779",

publisher = "Elsevier B.V.",

}

6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells. / Ratha, Radhakrishna; Singh, Ashish; Afroz, Mohammad Adil et al.
In: Synthetic Metals, Vol. 252, 01.06.2019, p. 113-121.

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

TY - JOUR

T1 - 6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells

AU - Ratha, Radhakrishna

AU - Singh, Ashish

AU - Afroz, Mohammad Adil

AU - Gupta, Ritesh Kant

AU - Baumgarten, Martin

AU - Müllen, Klaus

AU - Iyer, Parameswar Krishnan

PY - 2019/6/1

Y1 - 2019/6/1

N2 - This work emphasizes on the synthesis of two new acceptor units for donor (D)-acceptor (A)-based polymers used in photovoltaic devices, namely NT-Th and Th-NT-Th. Both the NT-based acceptors have been designed using 5,6-positions of benzothiadiazole (BT) and synthesized by Wittig coupling reaction. Newly synthesized acceptor units distinguishes itself from existing literature of naphtho[2,3-c][1,2,5]thiadiazole (NT) acceptor in having additional two Thiophene (Th) units attached at 6,7 position of NT, imparting into it a unique 2-dimensional (2D) type of conjugated structure. Alternate D-A co-polymer of new NT-based acceptors with commonly used BDT donor was synthesized via Stille coupling, resulting in new conjugated polymers (CPs) namely P(BDT-NTTh) and P(BDT-ThNTTh). Both the CPs were characterized by GPC, UV–vis, 1H-NMR, 13C-NMR, TGA and CV. Dihedral angle for optimized geometry and ICT of newly synthesized NT-based polymers have also been investigated using DFT. Theoretical calculations suggest that incorporating two Th-units, separates the donor and acceptor as in case of P(BDT-ThNTTh) leading to lowering of dihedral angle, with maximum value of 42.9˚ resulting in more planar geometry. PSC performance of synthesized CPs have been examined by fabricating BHJ solar cells with configuration ITO/PEDOT:PSS/Polymer-PC71BM/LiF/Al, which resulted in a PCE of 0.34% and 1.31% with P(BDT-NTTh) and P(BDT-ThNTTh) respectively. Hole-mobility for blend of P(BDT-NTTh) and P(BDT-ThNTTh) with PC71BM were calculated using SCLC (space charge limited current) method by fabricating hole only devices of configuration ITO/PEDOT:PSS/Polymer-PC71BM/Cu and mobility of 2.2 × 10−6 and 1.5 × 10-5 cm2 V-1 s-1 were established respectively. Morphology of active layer of fabricated PSC has been studied with atomic force microscopy (AFM) and is correlated with their performances.

AB - This work emphasizes on the synthesis of two new acceptor units for donor (D)-acceptor (A)-based polymers used in photovoltaic devices, namely NT-Th and Th-NT-Th. Both the NT-based acceptors have been designed using 5,6-positions of benzothiadiazole (BT) and synthesized by Wittig coupling reaction. Newly synthesized acceptor units distinguishes itself from existing literature of naphtho[2,3-c][1,2,5]thiadiazole (NT) acceptor in having additional two Thiophene (Th) units attached at 6,7 position of NT, imparting into it a unique 2-dimensional (2D) type of conjugated structure. Alternate D-A co-polymer of new NT-based acceptors with commonly used BDT donor was synthesized via Stille coupling, resulting in new conjugated polymers (CPs) namely P(BDT-NTTh) and P(BDT-ThNTTh). Both the CPs were characterized by GPC, UV–vis, 1H-NMR, 13C-NMR, TGA and CV. Dihedral angle for optimized geometry and ICT of newly synthesized NT-based polymers have also been investigated using DFT. Theoretical calculations suggest that incorporating two Th-units, separates the donor and acceptor as in case of P(BDT-ThNTTh) leading to lowering of dihedral angle, with maximum value of 42.9˚ resulting in more planar geometry. PSC performance of synthesized CPs have been examined by fabricating BHJ solar cells with configuration ITO/PEDOT:PSS/Polymer-PC71BM/LiF/Al, which resulted in a PCE of 0.34% and 1.31% with P(BDT-NTTh) and P(BDT-ThNTTh) respectively. Hole-mobility for blend of P(BDT-NTTh) and P(BDT-ThNTTh) with PC71BM were calculated using SCLC (space charge limited current) method by fabricating hole only devices of configuration ITO/PEDOT:PSS/Polymer-PC71BM/Cu and mobility of 2.2 × 10−6 and 1.5 × 10-5 cm2 V-1 s-1 were established respectively. Morphology of active layer of fabricated PSC has been studied with atomic force microscopy (AFM) and is correlated with their performances.

KW - 2D polymer

KW - Dihedral angle

KW - Donor-acceptor conjugated polymer

KW - Napthothiadiazole (NT)

KW - Polymer solar cell (PSC)

UR - https://www.scopus.com/pages/publications/85064509107

U2 - 10.1016/j.synthmet.2019.04.013

DO - 10.1016/j.synthmet.2019.04.013

M3 - Article

AN - SCOPUS:85064509107

SN - 0379-6779

VL - 252

SP - 113

EP - 121

JO - Synthetic Metals

JF - Synthetic Metals

ER -

6,7-Di(thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole and 4,6,7,9-tetra (thiophen-2-yl)naphtho[2,3-c][1,2,5]thiadiazole as new acceptor units for D-A type co-polymer for polymer solar cells

Abstract

Keywords

ASJC Scopus subject areas

UN SDGs

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