Abstract
Two non-fullerene acceptors, PNDIT-20 and PNDIT-16, based on naphthalenediimide (NDI) and thiophene comonomers, have been synthesized for all polymer solar cells (all-PSCs) application. The incorporation of long alkyl chains onto the NDI units endows the polymers with excellent solubility in both halogen and non-halogen solvents. Halogen-free solvents, e.g. 1,3,5-trimethylbenzene (1,3,5-TMB), 1,2,4-trimethylbenzene (1,2,4-TMB), and 1,2-dimethylbenzene (1,2-DMB), have been employed to fabricate all-PSCs based on PNDIT-20 or PNDIT-16 paired with a donor polymer PTB7-Th without use of additives or post-treatment. The devices using 1,2-DMB as the solvent demonstrated PCEs of 3.88% and 4.94% for PNDIT-20 and PNDIT-16, respectively, which are among the highest values reported for PNDIT-based all-PSCs produced using environmentally friendly solvent. The performance is superior than the control device fabricated from conventional but hazardous 1,2-dichlorobenzene (1,2-DCB). Space-charge-limited current (SCLC) measurements and active layer morphological investigation revealed that non-halogenated solvent processed devices show higher and more balanced hole and electron mobilities as well as favorable surface morphology for charge transfer. The results reported in this work suggest that non-halogenated solvents for all-PSCs processing are greatly promising for the development of high performance all-PSCs.
Original language | English |
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Pages (from-to) | 203-210 |
Number of pages | 8 |
Journal | Organic Electronics |
Volume | 46 |
DOIs | |
Publication status | Published - 1 Jul 2017 |
Externally published | Yes |
Keywords
- Conjugated polymer
- Low bandgap polymer
- Non-fullerene acceptor
- Non-halogenated solvent
- Organic solar cells
- Photovoltaic
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Chemistry
- Biomaterials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry