Document Type

Journal Article

Department/Unit

Department of Chemistry; Office of the Vice-President (Research and Development)

Title

New terthiophene-conjugated porphyrin donors for highly efficient organic solar cells

Language

English

Abstract

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.

Keywords

molecular packing, organic solar cells, peripheral substitutions, porphyrin, terthiophene

Publication Date

11-2016

Source Publication Title

ACS Applied Materials and Interfaces

Volume

8

Issue

44

Start Page

30176

End Page

30183

Publisher

American Chemical Society

Peer Reviewed

1

Copyright

© 2016 American Chemical Society

Funder

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.

DOI

10.1021/acsami.6b09790

Link to Publisher's Edition

http://dx.doi.org/10.1021/acsami.6b09790

ISSN (print)

19448244

ISSN (electronic)

19448252

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