9-arylidene-9H-fluorene-containing polymers for high efficiency polymer solar cells.
9-Arylidene-9H-fluorene containing donor-acceptor (D-A) alternating polymers P1 and P2 were synthsized and used for the fabrication of polymer solar cells (PSCs). High and low molecular weight P1 (HMW-P1 and LMW-P1) and high molecular weight P2 were prepared to study the influence of molecular weight and the position of alkoxy chains on the photovoltaic performance of PSCs. HMW-P1:PC71BM-based PSCs fabricated from 1,2-dichlorobenzene (DCB) solutions showed a power conversion efficiency (PCE) of 6.26%, while LMW-P1:PC71BM-based PSCs showed poor photovoltaic performance with a PCE of only 2.75%. PCE of HMW-P1:PC71BM-based PSCs was further increased to 6.52% with the addition of 1,8-diiodooctane (DIO) as the additive. Meanwhile, PCE of only 2.51% was obtained for P2:PC71BM-based PSCs. The results indicated that the position of alkoxy substituents on the 9-arylidene-9H-fluorene unit and the molecular weight of polymers are very crucial to the photovoltaic performance of PSCs.
Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Beijing Normal University , Beijing 100875, China.
Qian
Q
Liu
Cuihong
C
Li
Enquan
E
Jin
Zhen
Z
Lu
Youchun
Y
Chen
Fenghong
F
Li
Zhishan
Z
Bo