Abstract
A semicrystalline low-bandgap polymer (PDTPBT) based on alternating dithienopyrrole and benzothiadiazole moieties as a pair of the indene-C 60 bisadduct (ICBA) for polymeric solar cells is reported. The lowest unoccupied molecular orbital (LUMO) level of PDTPBT is measured to be -3.47 eV, ensuring sufficient energy offset for photoinduced charge transfer to ICBA. Photovoltaic cells are fabricated with ICBA and [6,6]-phenyl-C 71-butyric acid methyl ester (PC71BM) as an acceptor. By replacing PC71BM with ICBA, the open-circuit voltage is increased by 0.23 V and the resulting power conversion efficiency is improved from 1.17% to 1.71%. To optimize the ICBA-based devices, crystalline low-bandgap structures should be designed carefully as a pair of ICBA by considering the energy-level offset for charge separation and crystalline interchain ordering, for minimizing the intercalated ICBAs inside the polymer domain. A semicrystalline copolymer based on dithienopyrrole and benzothiadiazole is investigated as an active layer with the indene-C60 bisadduct (ICBA) for photovoltaic devices. A low-bandgap structure should be carefully designed as a pair of ICBA by considering the energy level offset for exciton separation and crystalline ordering for minimizing the intercalated ICBAs inside the polymer domain.
Original language | English |
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Pages (from-to) | 2083-2090 |
Number of pages | 8 |
Journal | Macromolecular Chemistry and Physics |
Volume | 214 |
Issue number | 18 |
DOIs | |
Publication status | Published - 2013 Sep |
Externally published | Yes |
Keywords
- charge transfer
- dithienopyrrole
- indene-C60 bisadduct (ICBA)
- polymer solar cells
- wide-angle X-ray scattering (WAXS)
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Organic Chemistry
- Materials Chemistry