Abstract
An asymmetric wide-bandgap (WBG) nonfullerene acceptor (C6-IDTT-T) is developed by shearing one alkyl side-chain from a symmetrically alkyl-substituted indacenodithieno[3,2-b]thiophene (IDTT) core of the fused-ring electron acceptor 2C6-IDTT-T. These two acceptors both exhibit wide optical bandgaps over 1.8 eV. Investigations on the optical, electrochemical, and active layer morphology are conducted to understand the effect of asymmetric side chains on the electrical and photovoltaic properties. Compared with symmetric 2C6-IDTT-T, asymmetric C6-IDTT-T is found to exhibit redshifted absorption and higher electron mobility. As a result, the C6-IDTT-T blend with a thienothiophene-benzodithiophene copolymer (PTB7-Th) presents higher electron mobility and more balanced charge carrier transport, which leads to an enhanced power conversion efficiency of 8.51% for C6-IDTT-T-based device with a high open-circuit voltage of 1.052 V and a low energy loss of 0.60 eV.
Original language | English |
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Article number | 2000061 |
Journal | Solar RRL |
Volume | 4 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2020 May 1 |
Bibliographical note
Publisher Copyright:© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- alkyl tailoring strategy
- asymmetric nonfullerene acceptors
- efficiency
- open-circuit voltages
- wide bandgaps
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy Engineering and Power Technology
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering