1. Optimization Requirements of Efficient Polythiophene:Nonfullerene Organic Solar Cells
- Author
-
Long Ye, Harald Ade, Ziqi Liang, Zhongxiang Peng, Yunfeng Deng, Miaomiao Li, Sam J. Stuard, Yunpeng Qin, Yanhou Geng, and Qi Wang
- Subjects
Materials science ,Organic solar cell ,Photovoltaic system ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Miscibility ,Acceptor ,0104 chemical sciences ,chemistry.chemical_compound ,Crystallinity ,General Energy ,chemistry ,Chemical engineering ,Homogeneous ,Polythiophene ,Mixed phase ,0210 nano-technology - Abstract
Summary Polythiophene (PT) and its derivatives have attracted long-standing attention in the organic photovoltaic community for their low cost and high scalability of synthesis. However, due to the lack of rational guidelines in controlling morphology and matching materials, the power conversion efficiencies (PCEs) based on PTs reported so far are generally below 10%. Here, we establish the first-ever relationship between miscibility, morphology, and device performance of binary blends, based on various nonfullerene acceptors (ITIC-Th1, ITIC, IT4F, IDIC, and Y6) and a PT derivative named PDCBT-Cl by scattering and calorimetric characterizations. Benefiting from a properly quenched mixed phase, PDCBT-Cl:ITIC-Th1 system shows the best efficiency of over 12%. Conversely, the blend of PDCBT-Cl and the star acceptor Y6 remained in a homogeneous state due to their high miscibility, resulting in abysmal performance with PCE of 0.5%. Specific guidelines are also proposed to remediate the performance of PDCBT-Cl:Y6, which are crucial for advancing their practical applications.
- Published
- 2020