polymers—new members of the acenodithiophene family exhibiting high mobility and power conversion efficiency

DOI: 10.1002/adfm.201602285

Authors: Astrid-Caroline Knall (Imperial College London; Graz University of Technology) , Raja Shahid Ashraf (Imperial College London) , Mark Nikolka (University of Cambridge) , Christian B. Nielsen (Imperial College London; Queen Mary University of London) , Balaji Purushothaman (Imperial College London) , Aditya Sadhanala (University of Cambridge) , Michael Hurhangee (Imperial College London) , Katharina Broch (University of Cambridge) , David J. Harkin (University of Cambridge) , Jiří Novák (Masaryk University) , Marios Neophytou (King Abdullah University of Science and Technology (KAUST)) , Pascal Hayoz (BASF Schweiz AG) , Henning Sirringhaus (University of Cambridge) , Iain Mcculloch (Imperial College London; King Abdullah University of Science and Technology (KAUST))
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Advanced Functional Materials , VOL 26 , PAGES 6961 - 6969

State: Published (Approved)
Published: October 2016

Abstract: 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.

Journal Keywords: conjugated polymers; organic field-effect transistors; organic semiconductors; organic solar cells

Diamond Keywords: Photovoltaics; Semiconductors

Subject Areas: Materials, Chemistry, Energy


Instruments: I07-Surface & interface diffraction

Added On: 04/04/2017 09:38

Discipline Tags:

Surfaces Earth Sciences & Environment Sustainable Energy Systems Energy Physics Climate Change Physical Chemistry Energy Materials Chemistry Materials Science Polymer Science

Technical Tags:

Scattering Wide Angle X-ray Scattering (WAXS) Grazing Incidence Wide Angle Scattering (GIWAXS)