Energy Level Tuning of Poly(phenylene-alt-dithienobenzothiadiazole)s for Low Photon Energy Loss Solar Cells

TitleEnergy Level Tuning of Poly(phenylene-alt-dithienobenzothiadiazole)s for Low Photon Energy Loss Solar Cells
Publication TypeJournal Article
Year of Publication2017
AuthorsR. Heuvel, J.J van Franeker, R.AJ Janssen
JournalMacromolecular Chemistry and Physics
Volume218
Issue5
Pagination1600502
Abstract

Six poly(phenylene-alt-dithienobenzothiadiazole)-based polymers have been synthesized for application in polymer–fullerene solar cells. Hydrogen, fluorine, or nitrile substitution on benzo­thiadiazole and alkoxy or ester substitution on the phenylene moiety are investigated to reduce the energy loss per converted photon. Power conversion efficiencies (PCEs) up to 6.6% have been obtained. The best performance is found for the polymer–fullerene combination with distinct phase separation and crystalline domains. This improves the maximum external quantum efficiency for charge formation and collection to 66%. The resulting higher photocurrent compensates for the relatively large energy loss per photon (E loss = 0.97 eV) in achieving a high PCE. By contrast, the poly­mer that provides a reduced energy loss (E loss = 0.49 eV) gives a lower photocurrent and a reduced PCE of 1.8% because the external quantum efficiency of 17% is limited by a suboptimal morphology and a reduced driving force for charge transfer. (Figure presented.). © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

DOI10.1002/macp.201600502
Division

MaSF

Department

MSE

PID

87ed7bc4fdc8e8c25c395f8df08d5d4f

Alternate TitleMacromol. Chem. Phys.
LabelOA

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