Department of Chemistry; Office of the Vice-President (Research and Development)
New terthiophene-conjugated porphyrin donors for highly efficient organic solar cells
To mimic the natural photosynthetic systems utilizing chlorophylls to absorb light and store light energy, two new porphyrin-based small molecules of PTTR and PTTCNR have been developed for photovoltaic applications. The highest power conversion efficiency of 8.21% is achieved, corresponding to a short-circuit current of 14.30 mA cm–2, open-circuit voltage of 0.82 V, and fill factor of 70.01%. The excellent device performances can be ascribed to the engineering of molecule structure and film morphology. The horizontal conjugation of 3,3″-dihexyl-terthiophene to porphyrin-core with the vertical aliphatic 2-octylundecyl peripheral substitutions, can not only effectively increase the solar flux coverage between the conventional Soret and Q bands of porphyrin unit, but also optimize molecular packing through polymorphism associated with side-chains and the linear π-conjugated backbones. And the additive of 1,8-diiodooctane and subsequent chloroform solvent vapor annealing facilitate the formation of the blend films with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) characteristics of bicontinuous, interpenetrating networks required for efficient charge separation and transportation.
molecular packing, organic solar cells, peripheral substitutions, porphyrin, terthiophene
Source Publication Title
ACS Applied Materials and Interfaces
American Chemical Society
© 2016 American Chemical Society
This work was financially supported by International Science & Technology Cooperation Program of China (2013DFG52740, 2010DFA52150) and the National Natural Science Foundation of China (51473053, 51073060, 91222201, 91333206). X.Z., W.-K.W., and W.-Y.W. thank Hong Kong Research Grants Council (HKBU 22304115-ECS, HKBU 203011), Hong Kong Baptist University (FRG1/14-15/058, FRG2/13-14/083, and RC-ICRS/15-16/02) and Areas of Excellence Scheme ([AoE/ P-03/08]) for the financial support. W.-Y.W. also acknowledges the Hong Kong Polytechnic University for the financial support. F.L. was financially supported by the U.S. Department of Energy, Office of Basic Energy Sciences (DE-SC0001087). Specifically, X.Z. and X.B.P. thank Chang Liu, Junbiao Peng (SCUT), and Ben Ong (HKBU) for their help and discussions in this work.
Link to Publisher's Edition
Xiao, Liangang, Song Chen, Ke Gao, Xiaobin Peng, Feng Liu, Yong Cao, Wai-Yeung Wong, Wai-Kwok Wong, and Xunjin Zhu. "New terthiophene-conjugated porphyrin donors for highly efficient organic solar cells." ACS Applied Materials and Interfaces 8.44 (2016): 30176-30183.