1. Non-fullerene small molecular acceptors with a carbazole core for organic solar cells with high open-circuit voltage.
- Author
-
Ma, Danyang, Feng, Shiyu, Zhang, Jicheng, Kou, Chun, Gong, Xue, Li, Qiaosheng, Xu, Xinjun, Yan, Shouke, and Bo, Zhishan
- Subjects
- *
CARBAZOLE , *SOLAR cells , *OPEN-circuit voltage , *SUBSTITUENTS (Chemistry) , *ELECTROPHILES - Abstract
Two novel carbazole-cored small molecules CzC6C8 and CzC8 bearing different side chains and two 3-ethylrhodanine end-capping groups were synthesized and used as electron acceptors in organic solar cells (OSCs). Devices based on these two acceptors showed a high open circuit voltage ( V oc ) about 1 V. Due to more closely molecular stacking and improved film morphology, CzC8 bearing a linear alkyl side chain showed a better photovoltaic performance than CzC6C8 bearing a branched one. CzC8 based OSCs can still exhibit a good performance even though the Δ E LUMO and Δ E HOMO between donor and acceptor are both small. Three polymer donors (PBT, PTB7-Th, and PTFBDT) with a similar LUMO level but various HOMO levels were tested and they all showed good PCE values larger than 4.6%. Among them, PTB7-Th: CzC8 based devices afforded the highest PCE of 4.91% and PTFBDT: CzC8 based ones gave the highest V oc of 1.16 V. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF