Naphthacenodithiophene Based Polymers—New Members of the Acenodithiophene Family Exhibiting High Mobility and Power Conversion Efficiency

Wide‐bandgap conjugated polymers with a linear naphthacenodithiophene (NDT) donor unit are herein reported along with their performance in both transistor and solar cell devices. The monomer is synthesized starting from 2,6‐dihydroxynaphthalene with a double Fries rearrangement as the key step. By copolymerization with 2,1,3‐benzothiadiazole (BT) via a palladium‐catalyzed Suzuki coupling reaction, NDT‐BT co‐polymers with high molecular weights and narrow polydispersities are afforded. These novel wide‐bandgap polymers are evaluated as the semiconducting polymer in both organic field effect transistor and organic photovoltaic applications. The synthesized polymers reveal an optical bandgap in the range of 1.8 eV with an electron affinity of 3.6 eV which provides sufficient energy offset for electron transfer to PC70BM acceptors. In organic field effect transistors, the synthesized polymers demonstrate high hole mobilities of around 0.4 cm2 V–1 s–1. By using a blend of NDT‐BT with PC70BM as absorber layer in organic bulk heterojunction solar cells, power conversion efficiencies of 7.5% are obtained. This value is among the highest obtained for polymers with a wider bandgap (larger than 1.7 eV), making this polymer also interesting for application in tandem or multijunction solar cells.

[1]  N. Stingelin,et al.  A Novel Alkylated Indacenodithieno[3,2‐b]thiophene‐Based Polymer for High‐Performance Field‐Effect Transistors , 2016, Advanced materials.

[2]  Zhishan Bo,et al.  4-Alkyl-3,5-difluorophenyl-Substituted Benzodithiophene-Based Wide Band Gap Polymers for High-Efficiency Polymer Solar Cells. , 2016, ACS applied materials & interfaces.

[3]  Christoph J. Brabec,et al.  Air-processed polymer tandem solar cells with power conversion efficiency exceeding 10% , 2015 .

[4]  Thomas Kirchartz,et al.  Role of Polymer Fractionation in Energetic Losses and Charge Carrier Lifetimes of Polymer: Fullerene Solar Cells , 2015 .

[5]  Luping Yu,et al.  Recent Advances in Bulk Heterojunction Polymer Solar Cells. , 2015, Chemical reviews.

[6]  A. Amassian,et al.  A Thieno[3,2‐b][1]benzothiophene Isoindigo Building Block for Additive‐ and Annealing‐Free High‐Performance Polymer Solar Cells , 2015, Advanced materials.

[7]  D. Chung,et al.  Synthesis and Charge Transport Properties of Conjugated Polymers Incorporating Difluorothiophene as a Building Block , 2015 .

[8]  A. Heeger,et al.  Single‐Junction Organic Solar Cells Based on a Novel Wide‐Bandgap Polymer with Efficiency of 9.7% , 2015, Advanced materials.

[9]  Feng Liu,et al.  Single-junction polymer solar cells with high efficiency and photovoltage , 2015, Nature Photonics.

[10]  He Yan,et al.  Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells , 2014, Nature Communications.

[11]  David Beljonne,et al.  Approaching disorder-free transport in high-mobility conjugated polymers , 2014, Nature.

[12]  Yang Yang,et al.  An Efficient Triple‐Junction Polymer Solar Cell Having a Power Conversion Efficiency Exceeding 11% , 2014, Advanced materials.

[13]  Christoph J. Brabec,et al.  Environmentally Printing Efficient Organic Tandem Solar Cells with High Fill Factors: A Guideline Towards 20% Power Conversion Efficiency , 2014 .

[14]  A. Amassian,et al.  Importance of the donor:fullerene intermolecular arrangement for high-efficiency organic photovoltaics. , 2014, Journal of the American Chemical Society.

[15]  V. Snieckus,et al.  Directed ortho metalation strategies. Effective regioselective routes to 1,2-, 2,3-, and 1,2,3-substituted naphthalenes. , 2014, Organic letters.

[16]  S. Holliday,et al.  Advances in Charge Carrier Mobilities of Semiconducting Polymers Used in Organic Transistors , 2014 .

[17]  Gang Li,et al.  25th Anniversary Article: A Decade of Organic/Polymeric Photovoltaic Research , 2013, Advanced materials.

[18]  Gang Li,et al.  Recent trends in polymer tandem solar cells research , 2013 .

[19]  Henning Sirringhaus,et al.  Molecular origin of high field-effect mobility in an indacenodithiophene–benzothiadiazole copolymer , 2013, Nature Communications.

[20]  Stuart R. Thomas,et al.  The Influence of Polymer Purification on Photovoltaic Device Performance of a Series of Indacenodithiophene Donor Polymers , 2013, Advanced materials.

[21]  C. B. Nielsen,et al.  Recent advances in high mobility donor-acceptor semiconducting polymers , 2012 .

[22]  C. B. Nielsen,et al.  Design of semiconducting indacenodithiophene polymers for high performance transistors and solar cells. , 2012, Accounts of chemical research.

[23]  T. Anthopoulos,et al.  Synthesis of a novel fused thiophene-thieno[3,2-b]thiophene-thiophene donor monomer and co-polymer for use in OPV and OFETs. , 2011, Macromolecular rapid communications.

[24]  Itaru Osaka,et al.  Thienoacene‐Based Organic Semiconductors , 2011, Advanced materials.

[25]  J. D. Mello,et al.  Indacenodithiophene-co-benzothiadiazole Copolymers for High Performance Solar Cells or Transistors via Alkyl Chain Optimization , 2011 .

[26]  Kristina J. Schottler,et al.  Cyclopentadithiazole-Based Monomers and Alternating Copolymers , 2010 .

[27]  Alberto Salleo,et al.  Indacenodithiophene semiconducting polymers for high-performance, air-stable transistors. , 2010, Journal of the American Chemical Society.

[28]  K. Araki,et al.  Experimental and theoretical studies on constitutional isomers of 2,6-dihydroxynaphthalene carbaldehydes. Effects of resonance-assisted hydrogen bonding on the electronic absorption spectra. , 2009, The Journal of organic chemistry.