Abstract
In this study, we have synthesized a new asymmetric n-type semiconducting molecule (Me-ITBD) by combining 4,4-bis(4-hexylphenyl)-7-methyl-6-(thiophen-2-yl)-4H-indeno[1,2-b]thiophene with 2-(benzo[c][1,2,5]-thiadiazol-4-yl methylene)-malononitrile and applied it to polymer solar cells. Compared to the PhITBD acceptor without methyl substituent in the 7-position of the core, Me-ITBD showed a larger torsional angle between thiophene and indenothiophene. Non-fullerene polymer solar cells (PSCs) with the methyl-substituted asymmetric acceptor Me-ITBD displayed an enhanced power conversion efficiency (PCE) of 5.75%, compared to the PSC (PCE = 1.79%) based on a PhITBD acceptor. The higher PCE value of the Me-ITBD-based PSC was ascribed to its improved device parameters, i.e. the Jsc and FF, induced by a favorable fine morphology in the active layer. By simply introducing a methyl substituent in the indenothiophene unit of the PhITBD acceptor, the PSC performance was enhanced.
Original language | English |
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Pages (from-to) | 164-171 |
Number of pages | 8 |
Journal | Synthetic Metals |
Volume | 246 |
DOIs | |
Publication status | Published - 2018 Dec |
Bibliographical note
Funding Information:We would like to thank the National Research Foundation of Korea ( NRF2018R1D1A1B07042533 , NRF20100020209 ) for their support in carrying out this study.
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Acceptor
- Asymmetric structure
- Indenothiophene
- Methyl substituent
- Polymer solar cell
- Power conversion efficiency
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry