A series of simple oligomer-like small molecules based on oligothiophenes for solution-processed solar cells with high efficiency

Bin Kan; Miaomiao Li; Qian Zhang; Feng Liu; Xiangjian Wan; Yunchuang Wang; Wang Ni; Guankui Long; Xuan Yang; Huanran Feng; Yi Zuo; Mingtao Zhang; Fei Huang; Yong Cao; Thomas P Russell; Yongsheng Chen

doi:10.1021/jacs.5b00305

A series of simple oligomer-like small molecules based on oligothiophenes for solution-processed solar cells with high efficiency

J Am Chem Soc. 2015 Mar 25;137(11):3886-93. doi: 10.1021/jacs.5b00305. Epub 2015 Mar 11.

Authors

Bin Kan¹, Miaomiao Li¹, Qian Zhang¹, Feng Liu², Xiangjian Wan¹, Yunchuang Wang¹, Wang Ni¹, Guankui Long¹, Xuan Yang¹, Huanran Feng¹, Yi Zuo¹, Mingtao Zhang³, Fei Huang⁴, Yong Cao⁴, Thomas P Russell², Yongsheng Chen¹

Affiliations

¹ †State Key Laboratory and Institute of Elemento-Organic Chemistry and Centre for Nanoscale Science and Technology, Institute of Polymer Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin 300071, China.
² ‡Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, United States.
³ ∥Computational Center for Molecular Science, College of Chemistry, Nankai University, Tianjin 300071, China.
⁴ §State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.

PMID: 25736989
DOI: 10.1021/jacs.5b00305

Abstract

A series of acceptor-donor-acceptor simple oligomer-like small molecules based on oligothiophenes, namely, DRCN4T-DRCN9T, were designed and synthesized. Their optical, electrical, and thermal properties and photovoltaic performances were systematically investigated. Except for DRCN4T, excellent performances were obtained for DRCN5T-DRCN9T. The devices based on DRCN5T, DRCN7T, and DRCN9T with axisymmetric chemical structures exhibit much higher short-circuit current densities than those based on DRCN6T and DRCN8T with centrosymmetric chemical structures, which is attributed to their well-developed fibrillar network with a feature size less than 20 nm. The devices based on DRCN5T/PC71BM showed a notable certified power conversion efficiency (PCE) of 10.10% under AM 1.5G irradiation (100 mW cm(-2)) using a simple solution spin-coating fabrication process. This is the highest PCE for single-junction small-molecule-based organic photovoltaics (OPVs) reported to date. DRCN5T is a rather simpler molecule compared with all of the other high-performance molecules in OPVs to date, and this might highlight its advantage in the future possible commercialization of OPVs. These results demonstrate that a fine and balanced modification/design of chemical structure can make significant performance differences and that the performance of solution-processed small-molecule-based solar cells can be comparable to or even surpass that of their polymer counterparts.